Zur Problematik von Blind-Studien
AN 14761905
AU Fergusson D, Glass KC, Waring D, Shapiro S
TI Turning a blind eye: the success
of blinding reported in a random sample
of randomised, placebo controlled trials.[see
comment]. [Review] [4 refs]
IN
SO BMJ. 328(7437):432, 2004 Feb 21.
CM Comment
in: BMJ. 2004 May 8;328(7448):1135-6; author reply
1136; PMID: 15130996, Comment in: BMJ. 2004 May 8;328(7448):1135;
author reply 1136; PMID: 15130995, Comment in: BMJ. 2004 May 8;328(7448):1136; PMID: 15130997
PT Publication
Type: Journal Article; Review; Review Literature
AB OBJECTIVE:
To examine the reporting and success of double blinding in a sample of
randomised, placebo controlled trials from leading general medicine and
psychiatry journals. METHODS: Identification of placebo controlled, randomised
controlled trials from prespecified general medical and psychiatric journals
indexed on Medline between
DE Descriptors:
*Double-Blind
Method; *Randomized Controlled Trials/mt [Methods]; Randomized Controlled
Trials/st [Standards]; Support, Non-U.S. Gov't
AN 15135549
AU Mooney M, White T, Hatsukami D
TI The blind spot in the nicotine replacement therapy
literature: assessment of the double-blind
in clinical trials. [Review] [49 refs]
IN Tobacco
Use Research Center, University of Minnesota, 2701 University Avenue S.E.,
Suite 201, Minneapolis, MN 55414, USA. Marc.E.Mooney@uth.tmc.edu
SO Addictive
Behaviors.
29(4):673-84, 2004 Jun.
PT Publication
Type: Journal Article; Meta-Analysis; Review; Review, Academic
AB While
clinical trials of medications often use a double-blind procedure, the integrity
of the blind
and its relationship to treatment outcome is seldom examined. In this review,
73 double-blind,
placebo-controlled clinical trials of the nicotine replacement therapies (NRTs)
in smoking cessation were identified. Seventeen articles were found that
assessed blindness
integrity,
demonstrating major variations in the assessment, analysis, and reporting of blindness
integrity.
Although 12 studies found that subjects accurately judged treatment assignment
at a rate significantly above chance, the available literature does not permit
definitive conclusions about blindness integrity. Recommendations for the assessment,
analysis, and reporting of blindness integrity are made. [References: 49]
DE Descriptors:
Controlled Clinical Trials; *Double-Blind Method; Human; *Nicotine/tu [Therapeutic
Use]; *Nicotinic Agonists/tu [Therapeutic Use]; *Smoking Cessation/mt
[Methods];
AN 2004120432
AU Bang H, Ni L, Davis CE
TI Assessment
of blinding in clinical trials.
IN H.
Bang, Department of Biostatistics, Univ. of N. Carolina at Chapel Hill, 137 E.
Franklin Street, Chapel Hill, NC 27599; United States. E-Mail: heejung_bang@unc.edu.
SO Controlled
Clinical Trials.
Vol. 25(2)(pp 143-156), 2004.
PT Publication
Type: Journal: Article
AB Success
of blinding
is a fundamental issue in many clinical trials. The validity of a trial may be
questioned if this important assumption is violated. Although thousands of
ostensibly double-blind trials are conducted annually and
investigators acknowledge the importance of blinding, attempts to measure
the effectiveness of blinding are rarely discussed. Several
published papers proposed ways to evaluate the success of blinding, but none of the
methods are commonly used or regarded as standard. This paper investigates a
new approach to assess the success of blinding in clinical trials. The blinding
index proposed is scaled to an interval of -1 to 1, 1 being complete lack of blinding,
0 being consistent with perfect blinding and -1 indicating opposite guessing
which may be related to unblinding. It has the ability to detect a
relatively low degree of blinding, response bias and different
behaviors in two arms. The proposed method is applied to a clinical trial of
cholesterol-lowering medication in a group of elderly people. (C) 2004 Elsevier
Inc. All rights reserved.
DE Descriptors:
*Hypocholesterolemic Agent; Placebo; *Double Blind Procedure; *Single Blind
Procedure; *Clinical Trial; Validation Process; Evaluation; Simulation;
Mathematical Model; Article
AN 15083477
AU
TI Analysis
of clinical data with breached blindness.
IN Millennium
Pharmaceuticals Inc.,
SO Statistics
in Medicine.
23(8):1185-93, 2004 Apr 30.
PT Publication
Type: Journal Article
AB In
clinical trials, blinding is usually employed to prevent bias
that may be introduced due to the knowledge of the identity of the treatment
codes. This bias could alter the conclusion of statistical inference on the
treatment effect. The purpose of this article is to propose a method for
analysing clinical data with breached blindness. The example regarding the study of
the effectiveness of an appetite suppressant in weight loss in obese woman as
described in Brownell and Stunkard (Am. J. Psychiatry 1982; 139:1487-1489) is
used to illustrate the application of the proposed methods. Copyright
2004 John Wiley & Sons, Ltd.
DE Descriptors:
Analysis of Variance; Appetite Depressants/tu [Therapeutic Use]; Bias
(Epidemiology); *Data Interpretation, Statistical; *Double-Blind Method; Female; Human;
Models, Statistical; Obesity/dt [Drug Therapy]; *Randomized Controlled
Trials/mt [Methods]; Randomized Controlled Trials/sn [Statistics &
Numerical Data]; Research Design; Treatment Outcome
AN 14608321
AU Bridgman S, Engebretsen L, Dainty K,
Kirkley A, Maffulli N, ISAKOS Scientific Committee
TI Practical aspects of
randomization and blinding in randomized
clinical trials.[erratum appears in Arthroscopy. 2004
Mar;20(3):A14].
IN Orthopaedic
Surgical Trial Unit,
SO Arthroscopy. 19(9):1000-6, 2003 Nov.
PT Publication
Type: Journal Article
AB Randomization
and blinding
are important tools in determining the effectiveness of a new intervention and
ensuring the validity of a clinical trial. However, randomness and
haphazardness are not equivalent. Randomization cannot overcome poor
experimental design or technique. Several types of randomization including
historical controls and pseudorandomization are discussed, as well as methods
of treatment allocation, stratification, and minimization techniques. The
importance of decreasing bias and the advantages and disadvantages of blinding
in randomized clinical trials are also covered.
DE Descriptors:
Bias (Epidemiology); Control Groups; *Double-Blind Method; Human; *Random
Allocation; Randomized Controlled Trials/mt [Methods]; *Randomized Controlled
Trials/sn [Statistics & Numerical Data]; Sampling Studies; *Single-Blind
Method
AN 14629838
AU Stambolovic V
TI Blind
trial: a subjugation tool.
SO Journal
of Alternative & Complementary Medicine. 9(5):615-7, 2003 Oct.
PT Publication
Type: Letter
DE Descriptors:
Complementary Therapies/mt [Methods]; *Complementary Therapies/st [Standards];
*Controlled Clinical Trials/st [Standards]; *Double-Blind Method; Human; Quality
Assurance, Health Care; Research Design/st [Standards]
AN 12707479
AU Sharpe L, Ryan B, Allard S, Sensky T
TI Testing for the integrity of blinding
in clinical trials: how valid are forced choice paradigms?.
IN
SO Psychotherapy
& Psychosomatics. 72(3):128-31, 2003 May-Jun.
PT Publication
Type: Journal Article
AB BACKGROUND:
In randomised controlled trials, an increasingly used test of the 'blindness'
of assessors is to have them guess the group to which each participant has been
allocated. Because assessors are usually aware of the trial hypotheses, we
predicted that trial participants who showed the greatest improvement would be
assumed by an assessor to have been in the 'preferred intervention' group.
METHODS: Data were derived from a trial in recent-onset rheumatoid arthritis
comparing cognitive behavioural therapy plus routine care with routine care
alone. RESULTS: Although in this trial assessor blindness was demonstrated,
patients 'guessed' by the assessor to be in the cognitive therapy group showed
significantly greater improvements than those predicted to have received
routine care alone in variables predicted to change in the study protocol.
CONCLUSIONS: These results indicate that even if an assessor's guesses about
patient group allocations are more accurate than expected by chance, this would
not necessarily demonstrate failure of blinding. This casts further doubt on the
validity of forced choice paradigms in testing the integrity of blinding in clinical trials.
Copyright 2003 S. Karger AG,
DE Descriptors:
Arthritis, Rheumatoid/px [Psychology]; Arthritis, Rheumatoid/th
[Therapy]; Cognitive Therapy; *Double-Blind Method; Human; *Randomized Controlled
Trials; Reproducibility of Results; Research Design; Support, Non-U.S. Gov't
AN 11829579
AU Devereaux PJ, Bhandari M, Montori VM, Manns
BJ, Ghali WA, Guyatt GH
TI Double blind, you are the weakest link--good-bye!.
SO ACP
Journal Club.
136(1):A11, 2002 Jan-Feb.
PT Publication
Type: Editorial
DE Descriptors:
*Double-Blind
Method; Human; Randomized Controlled Trials/mt [Methods]; Randomized Controlled
Trials/st [Standards]
AN 12088981
AU Flanagan N, Sherrington C
TI Effectiveness of blinding when comparing nitrous oxide with topical
anesthetic cream.[comment].
SO Anesthesia
& Analgesia.
95(1):251; author reply 251, 2002 Jul.
CM Comment
on: Anesth Analg. 2001 Sep;93(3):590-3; PMID: 11524323
PT Publication
Type: Comment; Letter
DE Descriptors:
Administration, Topical; *Anesthesia, Inhalation; *Anesthesia, Local;
*Anesthetics, Inhalation; *Anesthetics, Local; *Double-Blind Method; Human; *Nitrous
Oxide; *Randomized Controlled Trials/mt [Methods]; Research Design
AN 11964621
AU Park J, Lee H, White A, Ernst E
TI Suggesting an alternative
to the term "double-blind".
SO Anesthesiology. 96(4):1034; author reply 1035, 2002
Apr.
PT Publication
Type: Letter
DE Descriptors:
Acupuncture Analgesia; *Double-Blind Method; Human; Pain, Postoperative/th [Therapy]; Terminology
AN 2002116060
AU Devereaux PJ, Bhandari M, Montori VM, Manns
BJ, Ghali WA, Guyatt GH
TI 'Double blind, you are the weakest link - Goodbye!'.
IN Dr.
P.J. Devereaux,
SO Evidence
Based Medicine. Vol. 7(1)(pp 4-6), 2002.
PT Publication
Type: Journal: Article
DE Descriptors:
*Medical Research; *Double Blind Procedure; Methodology; Validation
Process; Clinical Study; Medical Information; Treatment Planning; Health
Practitioner; Outcomes Research; Data Analysis; Decision Making; Clinical
Practice; Human; Controlled Study; Article
AN 12026889
AU Devereaux PJ, Bhandari M, Montori VM, Manns
BJ, Ghall WA, Guyatt GH
TI Double blind, you have been voted off the island!.
IN
SO Evidence-Based
Mental Health.
5(2):36-7, 2002 May.
PT Publication
Type: Journal Article
DE Descriptors:
*Double-Blind
Method; *Randomized Controlled Trials
AN 12384193
AU Montori VM, Bhandari M, Devereaux PJ, Manns
BJ, Ghali WA, Guyatt GH
TI In the dark: the reporting
of blinding status in randomized
controlled trials.
IN Department
of Medicine, Mayo Clinic,
SO Journal
of Clinical Epidemiology. 55(8):787-90, 2002 Aug.
PT Publication
Type: Journal Article
AB To
determine the quality of reporting of blinding in randomized controlled trials
(RCTs), we evaluated 40 consecutive RCTs published in each of five leading
journals. We noted whether authors reported the blinding status of
participants, health care providers, data collectors,
judicial assessors of outcomes, data analysts, and manuscript writers. Explicit
reporting of blinding
status occurred in <25% of RCTs for all groups. Eighty-three RCTs, reported
as double-blind,
provided eight combinations of blinded groups. In conclusion, prestigious
journals do not currently report blinding status optimally. To do so, journals
should abandon the term "double blind" and explicitly report the blinding
status of the groups involved in RCTs. Until such reporting occurs, clinicians
will be left with uncertainty about the validity of RCTs that guide their
clinical practice.
DE Descriptors:
Bias (Epidemiology); *Double-Blind Method; Human; Journalism, Medical/st
[Standards]; *Journalism, Medical; Quality Control; *Randomized Controlled
Trials/mt [Methods]; *Randomized Controlled Trials/st [Standards]; Research
Design/st [Standards]; *Single-Blind Method;
AN 2002100901
AU Rodriguez Martin JL, Casado Collado A
TI Double-blind. The bias control in the
performance of clinical trials. Contradictions, lacks
and implications.
IN Dr.
J.L. Rodriguez Martin, Centro Cochrane Iberoamericano, Servei d'Epidemiol. Clin. Salut Pub., Hosp. de la Santa Creu i
Sant Pau, Sant Antoni M. Claret 171, 08041
SO Medicina
Clinica. Vol.
118(5)(pp 192-195), 2002. Date of Publication:
PT Publication
Type: Journal: Article
DE Descriptors:
*Double Blind
Procedure; *Clinical Trial; Epidemiology; Methodology;
AN 12353521
AU Mercer J
TI The difficulties of double blinding.[comment].
SO Science. 297(5590):2208, 2002 Sep 27.
CM Comment
on: Science. 2002 Jul 19;297(5580):325-6; PMID:
12130763
PT Publication
Type: Comment; Letter
DE Descriptors:
*Double-Blind
Method; Estrogen Replacement Therapy/ae [Adverse Effects]; *Estrogen
Replacement Therapy; Female; Human; Patient Compliance; Placebos; *Randomized
Controlled Trials
AN 11707879
AU Schulz KF
TI Assessing allocation
concealment and blinding in randomised
controlled trials: why bother?.
SO Evidence-Based
Nursing.
4(1):4-6, 2001 Jan.
PT Publication
Type: Editorial
AB As
users of RCT results, we must understand the potential for humans to interject
bias. By describing assessments of allocation concealment and blinding,
abstracts included in Evidence-Based Nursing will help readers to discern those
trials that have made superior efforts to minimise bias. Judging the quality of
allocation concealment and blinding reflects current empirical research
and reflects the commitment of the editors of this journal to apply the
principles of evidence-based practice to reporting of study findings.
DE Descriptors:
*Double-Blind
Method; Human; Random Allocation; Randomized Controlled Trials/mt [Methods];
*Randomized Controlled Trials/st [Standards]
AN 2001217108
AU Anonymous
TI Code
breaking in double-blind
trials.
SO Good
Clinical Practice Journal. Vol. 8(6)(pp 21), 2001.
PT Publication
Type: Journal: Note
DE Descriptors:
*Good Clinical Practice; *Double Blind Procedure; *Medical Ethics; Drug Safety;
Drug Information; Monitoring; Practice Guideline; Randomization; Professional
Standard; Clinical Protocol; General and Miscellaneous Procedures and
Techniques; Patient Monitoring; Note
AN 11308438
AU Devereaux PJ, Manns BJ, Ghali WA, Quan H,
Lacchetti C, Montori VM, Bhandari M, Guyatt GH
TI Physician interpretations
and textbook definitions of blinding
terminology in randomized controlled trials.[see
comment].
IN Department
of Medicine, McMaster University, 1200 Main St W, Room 2C12, Hamilton, Ontario,
Canada L8N 3Z5. philipj@mcmaster.ca
SO JAMA. 285(15):2000-3, 2001 Apr 18.
CM Comment
in: JAMA. 2001 Apr 18;285(15):2006-7; PMID: 11308440
PT Publication
Type: Journal Article
AB CONTEXT:
When clinicians assess the validity of randomized controlled trials (RCTs),
they commonly evaluate the blinding status of individuals in the RCT. The
terminology authors often use to convey blinding status (single, double, and triple blinding)
may be open to various interpretations. OBJECTIVE: To determine physician
interpretations and textbook definitions of RCT blinding terms. DESIGN AND
SETTING: Observational study undertaken at 3 Canadian university tertiary care
centers between February and May 1999. PARTICIPANTS: Ninety-one internal
medicine physicians who responded to a survey. MAIN OUTCOME MEASURES:
Respondents identified which of the following groups they thought were blinded
in single-, double-, and triple-blinded RCTs: participants, health care
providers, data collectors, judicial assessors of
outcomes, data analysts, and personnel who write the article. Definitions from
25 systematically identified textbooks published since 1990 providing
definitions for single, double, or triple blinding. RESULTS: Physician respondents
identified 10, 17, and 15 unique interpretations of single, double, and triple blinding,
respectively, and textbooks provided 5, 9, and 7 different definitions of each.
The frequencies of the most common physician interpretation and textbook
definition were 75% (95% confidence interval [CI], 65%-83%) and 74% (95% CI,
52%-90%) for single blinding, 38% (95% CI, 28%-49%) and 43% (95%
CI, 24%-63%) for double blinding, and 18% (95% CI, 10%-28%) and 14%
(95% CI, 0%-58%) for triple blinding, respectively. CONCLUSIONS: Our study
suggests that both physicians and textbooks vary greatly in their
interpretations and definitions of single, double, and triple blinding.
Explicit statements about the blinding status of specific groups involved in
RCTs should replace the current ambiguous terminology.
DE Descriptors:
*Double-Blind
Method; *Publishing/st [Standards]; *Randomized Controlled Trials/st
[Standards]; *Single-Blind Method; Support, Non-U.S. Gov't;
*Terminology
AN 2001183265
AU Kaptchuk TJ
TI The double-blind, randomized, placebo-controlled trial: Gold
standard or golden calf?.
IN T.J.
Kaptchuk,
SO Journal
of Clinical Epidemiology. Vol. 54(6)(pp 541-549), 2001.
PT Publication
Type: Journal: Review
AB The
double-blind
randomized controlled trial (RCT) is accepted by medicine as objective
scientific methodology that, when ideally performed, produces knowledge
untainted by bias. The validity of the RCT rests not just on theoretical
arguments, but also on the discrepancy between the RCT and less rigorous evidence
(the difference is sometimes considered an objective measure of bias). A brief
overview of historical and recent developments in 'the discrepancy argument' is
presented. The article then examines the possibility that some of this
'deviation from truth' may be the result of artifacts introduced by the masked
RCT itself. Can an 'unbiased' method produce bias? Among the experiments
examined are those that augment the methodological stringency of a normal RCT
in order to render the experiment less susceptible to subversion by the mind.
This methodology, a hypothetical 'platinum' standard, can be used to judge the
'gold' standard. The concealment in a placebo-controlled RCT seems capable of
generating a 'masking bias.' Other potential biases, such as 'investigator
self-selection,' 'preference,' and 'consent' are also briefly discussed. Such
potential distortions indicate that the double-blind RCT may not be
objective in the realist sense, but rather is objective in a 'softer'
disciplinary sense. Some 'facts' may not exist independent of the apparatus of
their production. (C) 2001 Elsevier Science Inc.
DE Descriptors:
*Placebo; *Double Blind Procedure; *Randomized Controlled Trial;
Validation Process; Science; Artifact; Apparatus; Outcomes Research; Informed
Consent; Alertness; Tension; Motor Performance; Pulse Rate; Systolic Blood
Pressure; Coffee; Human; Human Experiment; Normal Human; Controlled Study;
Review; Priority Journal
AN 11379846
AU Kumar S, Oakley-Browne M
TI Problems with ensuring a
double blind.[comment].
SO Journal
of Clinical Psychiatry. 62(4):295-6, 2001 Apr.
CM Comment
on: J Clin Psychiatry. 2000 Jan;61(1):26-9; PMID:
10695642
PT Publication
Type: Comment; Letter
DE Descriptors:
Comparative Study; Cyclohexanols/tu [Therapeutic Use]; Delusions/dt [Drug
Therapy]; Delusions/px [Psychology]; Depressive Disorder/dt [Drug Therapy];
Depressive Disorder/px [Psychology]; *Double-Blind Method; Fluvoxamine/tu
[Therapeutic Use]; Human; Randomized Controlled Trials/st [Standards];
*Research Design/st [Standards]; Serotonin Uptake Inhibitors/tu [Therapeutic
Use]
AN 11782039
AU Friede T, Kieser M
TI A
comparison of methods for adaptive sample size adjustment.
IN Medical
Biometry Unit,
SO Statistics
in Medicine.
20(24):3861-73, 2001 Dec 30.
PT Publication
Type: Journal Article
AB In
fixed sample size designs, precise knowledge about the magnitude of the outcome
variable's variance in the planning phase of a clinical trial is mandatory for
an adequate sample size determination. Wittes and Brittain introduced the
internal pilot study design that allows recalculation of the sample size during
an ongoing trial using the estimated variance obtained from an interim
analysis. However, this procedure requires the unblinding of the treatment
code. Since unblinding
of an ongoing trial should be avoided whenever possible, there should be some
benefit of this design compared with blinded sample size recalculation procedures
to justify the unveiling of the treatment code. In this paper, we compare
several sample size recalculation procedures with and without unblinding.
The simulation results indicate that the procedures behave similarly. In
particular, breaking
of the blind
is not required for an efficient sample size adjustment. We also compare these
pure sample size adaptation procedures with study designs which additionally
allow for early stopping. Evaluation of the cumulative distribution function of
the resulting sample sizes shows that the option for early stopping may lead to
lower expectation but generally to a higher variability. The procedures are
illustrated by an example of a trial in the treatment of depression. Copyright 2001 John Wiley & Sons, Ltd.
DE Descriptors:
Comparative Study; Computer Simulation; Depression/dt [Drug Therapy]; *Double-Blind
Method; Human; Hypericum/me [Metabolism]; Phytotherapy; *Randomized Controlled
Trials/mt [Methods]; *Sample Size; Support, Non-U.S. Gov't
AN 10948038
AU Day SJ, Altman DG
TI Statistics notes: blinding in clinical trials and other studies.
[Review] [4 refs]
IN Leo
Pharmaceuticals, Princes Risborough, Buckinghamshire HP27 9RR.
SO BMJ. 321(7259):504, 2000 Aug 19-26.
PT Publication
Type: Journal Article; Review; Review, Tutorial
DE Descriptors:
*Clinical Trials/mt [Methods]; *Double-Blind Method; Human; Single-Blind
Method
AN 10945088
AU Even C, Siobud-Dorocant E, Dardennes RM
TI Critical
approach to antidepressant trials. Blindness
protection is necessary, feasible and measurable. [Review] [22 refs]
IN Clinique
des Maladies Mentales et de l'Encephale, Centre
Hospitalier Sainte-Anne,
SO British
Journal of Psychiatry. 177:47-51, 2000 Jul.
PT Publication
Type: Journal Article; Review; Review Literature
AB BACKGROUND:
Double-blind
placebo-controlled trials are the academic standard for clinical
psychopharmacology research. AIMS: To identify the potential defects of current
double-blind
procedures in trials involving antidepressants and to investigate whether
safeguards for blindness protection are used. METHOD: We
reviewed the literature and devised a short seven-item checklist for evaluating
the quality of blindness protection. We performed a
computerised search for 1998 to identify the placebo-controlled studies that
evaluated the efficacy of an antidepressant. The checklist was used to assess
all traceable antidepressant trials published in 1998. RESULTS: Relevant
criticisms question the blindness procedures. The available methods
which may bolster blindness are very seldom used. CONCLUSIONS:
Improvement in the blindness procedures used for antidepressant
trials is necessary, feasible and measurable. [References: 22]
DE Descriptors:
*Antidepressive Agents/tu [Therapeutic Use]; *Controlled Clinical Trials/mt
[Methods]; *Depressive Disorder/dt [Drug Therapy]; *Double-Blind Method; Human;
Placebos; Retrospective Studies
AN 2000373748
AU Gissane C, Eston R, Rowlands A
TI Who should be blinded? (multiple
letters) [2].
IN C.
Gissane, Department of Health Studies, Brunel University, Osterley Campus,
Isleworth, Middlesex TW7 5DU; United Kingdom.
SO British
Journal of Sports Medicine. Vol. 34(5)(pp 403), 2000.
PT Publication
Type: Journal: Letter
DE Descriptors:
*Medical Research; *Single Blind Procedure; *Double Blind Procedure; Methodology;
Medical Literature; Sports Medicine; Randomized Controlled Trial; Outcomes
Research; Publication; Stretching; Exercise; Leg Injury; General Practitioner;
Clinical Practice; Human; Letter
AN 11624657
AU Marks HM
TI Trust and mistrust in the
marketplace: statistics and clinical research, 1945-1960.
IN
SO History
of Science. 38
Pt 3(121):343-55, 2000 Sep.
PT Publication
Type: Historical Article; Journal Article
DE Descriptors:
*Clinical Protocols; *Double-Blind Method; History of Medicine, 20th Cent.;
*Random Allocation; Risk; *Statistics/hi [History]
AN 11152048
AU Jobst KA
TI Blinding
and the tapestry of trial design: revealing the weaving and the woven.
SO Journal
of Alternative & Complementary Medicine. 6(6):475-7, 2000 Dec.
PT Publication
Type: Editorial
DE Descriptors:
*Clinical Trials; *Complementary Therapies; *Double-Blind Method; Human; Placebo
Effect
AN 11152049
AU Reilly D
TI The unblind leading the blind:
the Achilles heel of too many trials.
SO Journal
of Alternative & Complementary Medicine. 6(6):479-80, 2000 Dec.
PT Publication
Type: Editorial
DE Descriptors:
*Clinical Trials; *Double-Blind Method; Human; Placebo Effect
AN 11152053
AU Caspi O, Millen C, Sechrest L
TI Integrity
and research: introducing the concept of dual blindness.
how blind are
double-blind clinical trials in
alternative medicine?. [Review] [43 refs]
IN Department
of Psychology,
SO Journal
of Alternative & Complementary Medicine. 6(6):493-8, 2000 Dec.
PT Publication
Type: Journal Article; Review; Review, Tutorial
AB Double-blind
methodology is used in clinical studies to control for potential external or
nonspecific influences such as belief and expectation, as well as to maintain
as much objectivity as possible on the part of the researchers. Despite not
being feasible in all medical disciplines, as in the case of some modalities of
complementary and alternative medicine, there are numerous studies that
spuriously claim its use. Distinctions and standards therefore need to be set
to avoid misleading information. We propose a new term in research methodology,
dual-blind,
to describe a methodological alternative in which the caregiver is not blind
but the patient and an external evaluator/investigator are. The term double-blind
should be used strictly to describe a methodology in which both the patient and
the caregiver are blind. Making the distinction between these
two terms will result in more reliable reports of clinical trials and will
support integrity
in research. [References: 43]
DE Descriptors:
Bias (Epidemiology); Caregivers; *Clinical Trials; Complementary Therapies;
*Double-Blind
Method; Human; Patients; Placebo Effect
AU Beck P
TI Single
blind placebo in drug research.
SO J
Med Ethics 2000 Dec;26(6):477.
LG eng
PT Publication
Type: Comment; Letter
DE Descriptors:
Clinical Trials/*methods; Drug Evaluation/*standards; Human; *Human
Experimentation; Placebos/*standards; *Single-Blind Method;
AU Evans M
TI Justified deception? The single blind placebo in
drug research.
IN Centre
for Philosophy and Health Care,
SO J
Med Ethics 2000 Jun;26(3):188-93.
LG eng
PT Publication
Type: Journal Article
AB "Run-in"
and "washout" periods involving the withholding of medication are
widely used in drug research trials in pursuit of both patient safety and
scientific reliability. Such no-medication periods can be justified ethically
provided that they are apparent to patients, who can thereby properly consent
to undergoing them. Less widespread, but still common, is the practice of
"single blinding"
no-medication periods, concealing them from patients by means of placebo. Whilst all placebos involve a measure of
concealment, their use is typically justified in drug research trials (i) by
their preserving the uncertainty generated by the random allocation of
different treatments within a drug trial; and (ii) by the researchers openly
declaring both the randomisation process and the chances of receiving placebo.
In the single blind placebo "run-in" or "washout",
neither of these conditions is met. This paper considers three possible
defences of the practice of using single blind placebo "run-ins" or
"washouts" and finds them all to fail; the practice appears ethically
unjustified.
DE Descriptors:
Clinical Trials/*legislation & jurisprudence; *Deception; *Ethics, Medical;
Human; Informed Consent/legislation & jurisprudence; Morals; Research
Subjects; *Single-Blind Method; Therapeutic Human
Experimentation
AN 10234873
AU Sheldrake R
TI How widely is blind assessment used in scientific research?.
IN Institute
of Noetic Sciences,
SO Alternative
Therapies in Health & Medicine. 5(3):88-91, 1999 May.
PT Publication
Type: Journal Article
DE Descriptors:
*Double-Blind
Method; Human; *Research Design; *Single-Blind Method; Support, Non-U.S. Gov't
AN 1999146724
AU Strong III FC
TI The
history of the double blind test and the
placebo.
IN F.C.
Strong III,
SO Journal
of Pharmacy & Pharmacology. Vol. 51(3)(pp 237-238), 1999.
PT Publication
Type: Journal: Editorial
DE Descriptors:
Placebo; *Double Blind Procedure; Drug Screening; Editorial
AN 9810062
AU Dossey L
TI On double-blinds and double standards: a response to the
recent
SO Alternative
Therapies in Health & Medicine. 4(6):18, 20, 1998 Nov.
PT Publication
Type: Journal Article
DE Descriptors:
*Complementary Therapies; *Double-Blind Method; Human; Research/st [Standards]
AN 9825123
AU Knipschild PG, Hoerr R, Oschmann R, van Rossum E, van Dongen MC
TI Optimization
of placebos for double-blind clinical
trials. Experience with a phytopharmaceutical.
IN Department
of Epidemiology,
SO Arzneimittel-Forschung. 48(10):1033-6, 1998 Oct.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB The
maintenance of double-blind conditions in placebo-controlled trials
depends on the quality of the placebo preparation. The placebo should match the
active substance-containing preparation as closely as possible, but it must not
contain any substances that might themselves be pharmacologically active.
Active substances characterized by a particular colour, taste, smell or other
easily perceptible properties constitute a challenge to researchers. The way of
developing a placebo that matches a phytopharmaceutical to a satisfactory
extent is described and discussed.
DE Descriptors:
Aged; *Central Nervous System Agents/tu [Therapeutic Use]; *Clinical
Protocols/st [Standards]; Comparative Study; Dose-Response Relationship, Drug;
*Double-Blind
Method; *Flavonoids/tu [Therapeutic Use]; Human; *Memory Disorders/dt [Drug
Therapy]; Memory Disorders/et [Etiology]; *Placebos; Plant Extracts/tu
[Therapeutic Use]; *Randomized Controlled Trials/mt [Methods]; Randomized
Controlled Trials/st [Standards]
AN 9571262
AU Meinert CL
TI Masked
monitoring in clinical trials--blind
stupidity?.
IN
SO
PT Publication
Type: Journal Article
DE Descriptors:
Bias (Epidemiology); *Double-Blind Method; Human; *Randomized Controlled
Trials/mt [Methods]; Research Design
AN 9283510
AU Basoglu M, Marks I, Livanou M, Swinson R
TI Double-blindness procedures, rater blindness, and ratings of outcome. Observations from
a controlled trial.
IN Department
of Psychiatry,
SO Archives
of General Psychiatry. 54(8):744-8, 1997 Aug.
PT Publication
Type: Clinical Trial; Journal Article; Multicenter Study; Randomized Controlled
Trial
AB BACKGROUND:
We determined whether blindness in a double-blind randomized controlled
trial of alprazolam and exposure therapies in patients with panic disorder and
agoraphobia was maintained in assessors and patients, what were the factors
related to "unblinding," and whether unblinding
was associated with clinical outcome. METHOD: In 129 patients with panic
disorder and agoraphobia who were randomized to alprazolam-exposure,
placebo-exposure, alprazolam-relaxation, or placebo-relaxation conditions, blindness
was tested at the end of treatment by the independent assessors' and patients'
classification of the treatment condition. RESULTS: Assessors' classifications
were correct in 82% of the alprazolam group and 78% of the placebo group;
corresponding figures for patients' classifications were 73% and 70%,
respectively. Factors associated with unblinding included drug side effects but not
assessors' ratings of treatment outcome. CONCLUSION: Judgment of the validity
of the outcome of a randomized controlled trial is easier if the report notes
not only the use of a double-blindness procedure but also details how blind
the raters remained and how any unblinding affected their ratings of clinical
outcome.
DE Descriptors:
Agoraphobia/th [Therapy]; Alprazolam/ae [Adverse Effects]; Alprazolam/tu
[Therapeutic Use]; Combined Modality Therapy; *Double-Blind Method; Drug
Administration Schedule; Human; Panic Disorder/th [Therapy]; Placebos;
*Randomized Controlled Trials/st [Standards]; Relaxation Techniques; Support,
Non-U.S. Gov't; Treatment Outcome
AN 9158270
AU Ellis SJ, Adams RF
TI The
cult of the double-blind
placebo-controlled trial. [Review] [13 refs]
IN
SO British
Journal of Clinical Practice. 51(1):36-9, 1997 Jan-Feb.
PT Publication
Type: Journal Article; Review; Review, Academic
AB The
double-blind,
placebo-controlled trial is held as the gold standard in medical knowledge, but
this tool of investigation has its weaknesses. These include ethical
limitations on the types of comparison that can be undertaken, the central
conflict between best practice for an individual and trial protocols, problems
of applicability to the general population and applicability of work done on
one population to another, type II errors, publication bias, misuse and
limitation of statistics, fraud, maintenance of blinding, asking the wrong
question, and a simplistic, reductionist view of clinical management. The
concentration on the randomised, controlled trial devalues information from
other sources, such as natural history studies, clinical experience and case
reports. The randomised, controlled trial is an important source of information
and as physicians we should welcome more well-crafted trials, but they are not
the only source of information. [References: 13]
DE Descriptors:
*Controlled Clinical Trials/st [Standards]; *Double-Blind Method; False Negative
Reactions; Fraud; Human; *Publication Bias
AN 8795875
AU Kiene H
TI A
critique of the double-blind clinical
trial. Part 1. [Review] [41 refs]
IN Inno
Vision Communications,
SO Alternative
Therapies in Health & Medicine. 2(1):74-80, 1996 Jan.
PT Publication
Type: Journal Article; Review; Review, Tutorial
AB The
randomized, double-blind study is generally regarded as the gold
standard of clinical drug trials. Bias can occur as a result of the blinding
procedure itself, but discussions of this type of bias have been few and far
between. This article presents a detailed discussion of such blinding
errors, which can obscure genuine drug effects and be of a sufficient magnitude
as to generate false-negative results. Uncritical blinding in clinical studies
should therefore be questioned. [References: 41]
DE Descriptors:
Bias (Epidemiology); *Double-Blind Method; False Negative Reactions; Human;
*Randomized Controlled Trials/st [Standards]
AN 8795890
AU Kiene H
TI A critique of the double-blind clinical trial. Part 2. [Review] [36 refs]
IN Kritik der klinischen Doppelblindstudie, Munich, Germany.
SO Alternative
Therapies in Health & Medicine. 2(2):59-64, 1996 Mar.
PT Publication
Type: Journal Article; Review; Review, Tutorial
AB The
randomized, double-blind study is generally regarded as the gold
standard of clinical drug trials. Bias can occur as a result of the blinding
procedure itself, but discussions of this type of bias have been few and far
between. This article continues with a detailed discussion of such blinding
errors, which can obscure genuine drug effects and be of a sufficient magnitude
as to generate false-negative results. Uncritical blinding in clinical studies
should therefore be questioned. [References: 36]
DE Descriptors:
*Clinical Trials; *Double-Blind Method; Human; Research
AN 8889343
AU Gotzsche PC
TI Blinding during data analysis and writing of
manuscripts.
IN Nordic
Cochrane Centre, Rigshospitalet,
SO Controlled
Clinical Trials.
17(4):285-90; discussion 290-3, 1996 Aug.
PT Publication
Type: Journal Article
DE Descriptors:
*Bias (Epidemiology); Data Interpretation, Statistical; *Double-Blind
Method; Drug Evaluation/mt [Methods]; Drug Evaluation/st [Standards]; Human;
*Randomized Controlled Trials/mt [Methods]; Randomized Controlled Trials/st
[Standards]; *Research Design
AN 8889344
AU Haakenson C, Akiyama T, Hallstrom A, Sather MR
TI Masking drug treatments in the Cardiac Arrhythmia
Pilot Study (CAPS). FASHP for the CAPS Investigators.
IN VA
Cooperative Studies Program.
SO Controlled
Clinical Trials.
17(4):294-303, 1996 Aug.
PT Publication
Type: Clinical Trial; Controlled Clinical Trial; Journal Article; Randomized
Controlled Trial
AB The
effectiveness of masking in the Cardiac Arrhythmia Suppression Study (CAPS)
was assessed by surveying investigators and study coordinators. CAPS patients
were assigned one of five treatments: encainide, flecainide, imipramine,
moricizine, or placebo. Had all treatments appeared identical and equal numbers
of patients been assigned to each, 20% of guesses of treatment assignment would
be correct by chance alone. Since neither was possible in CAPS, higher rates of
correct guessing were expected. Overall, respondents correctly identified
treatment 39% of the time. Investigators identified the drug 30% of the time
with rates of 20%, 24%, 37%, 20%, and 55% for the five treatment groups,
respectively, whereas coordinators identified the treatments 47% of the time
with scores of 42%, 45%, 50%, 40%, and 60%. Side effects and a suboptimal masking
design detracted from masking; electrocardiographic changes did not
imipramine, which caused characteristic side effects, was the most frequently
identified active treatment. Scores were higher for investigators who had prior
experience with the drugs, but scores did not improve over the course of the
trial. Findings suggest that to improve masking all drugs should have been matched in
appearance or persons evaluating treatments should not have been allowed to see
the drugs.
DE Descriptors:
Anti-Arrhythmia Agents/pd [Pharmacology]; *Arrhythmia/dt [Drug Therapy];
Arrhythmia/et [Etiology]; *Bias (Epidemiology); *Clinical Trials/mt [Methods];
*Double-Blind
Method; *Drug Evaluation/mt [Methods]; Follow-Up Studies; Human; Myocardial
Infarction/co [Complications]; Pilot Projects; Placebos; Research Design;
Support, U.S. Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.
AN 1996258705
AU Boateng F, Sampson A, Schwab B
TI Statistical
analysis of possible bias of clinical judgements due to observing an on-therapy
marker variable.
IN RW
Johnson Pharmaceutical Res. Inst.,
SO Statistics
in Medicine.
Vol. 15(16)(pp 1747-1755), 1996.
PT Publication
Type: Journal: Article
AB In
certain double-blind clinical trials there is the possibility
that certain 'marker variables' observable during the trial may in part unblind
the trial, even at a subliminal level. At issue is whether or not this
potential unblinding
biases the investigators' clinical efficacy assessments. This issue arose after
the completion of three clinical trials that compared tretinoin emollient cream
(TEC) 0.05 per cent to its vehicle in patients with photodamaged skin, The
question raised was whether or not possible 'subliminal unblinding' of the
investigators and patients, due to the cutaneous irritation associated with
topical tretinoin, might have caused a treatment bias in the study. To address
this issue, we undertook a reanalysis of these three clinical trials. In doing
so, we develop in this paper a statistical modelling approach to address issues
of possible bias introduced by the ability to observe such marker variables.
The approach utilizes a linear discriminant analysis to introduce an auxiliary
categorical variable for the efficacy analysis. A suitable categorical data
model permits the estimation of relevant bias effects. We illustrate this
approach with data from the three TEC 0.05 per cent trials.
DE Descriptors:
Retinoic Acid/ae [Adverse Drug Reaction]; Retinoic Acid/ct [Clinical Trial];
Retinoic Acid/dt [Drug Therapy]; *Decision Making; *Double Blind Procedure; Article;
Clinical Trial; Controlled Study; Human; Light Damage/dt [Drug Therapy]; Skin
Irritation/si [Side Effect]; Statistical Analysis; Statistical Model
AN 1995304066
AU Garcia Puig J, Mateos Anton F, Gil Aguado
A, Barcina Sanchez C
TI Can the double blind be known prior to revealing of
identification codes? [1]. [Spanish]
IN Serv.
de Medicina Interna, Hospital La Paz, Laboratorios Zeneca Farma S.A.,
SO Medicina
Clinica. Vol.
105(11)(pp 437-438), 1995.
PT Publication
Type: Journal: Letter
DE Descriptors:
*Lisinopril/dt [Drug Therapy]; *Lisinopril/ct [Clinical Trial]; *Nifedipine/dt
[Drug Therapy]; *Nifedipine/ct [Clinical Trial]; *Double Blind Procedure; *Drug
Identification; Clinical Trial; Controlled Study; Diabetes Mellitus; Human;
Hypertension/dt [Drug Therapy]; Letter; Major Clinical Study; Microalbuminuria;
Multicenter Study
AN 7618021
AU Morin CM, Colecchi C, Brink D, Astruc M,
Mercer J, Remsberg S
TI How "blind" are double-blind
placebo-controlled trials of benzodiazepine hypnotics?.
IN
SO Sleep. 18(4):240-5, 1995 May.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB This
study examined the accuracy of insomnia patients and their treating physicians
in rating whether an active hypnotic drug or a placebo was given in treatment.
Forty older adults with primary insomnia were randomly assigned to either an
active (temazepam) or a placebo condition using a double-blind strategy. Ratings of
treatment conditions were obtained at 1 week (early treatment), 4 weeks
(midtreatment), and 8 weeks (late treatment). Patients were able to accurately
discriminate (beyond chance levels) between the active and placebo medications
at the early (76.9% accuracy) and late treatment assessment timepoints (78.1%
accuracy), but not at midtreatment (51.5% accuracy). Therapists, however, were
able to make accurate discriminations at the late treatment assessment
timepoint only (80% accuracy); early (69.2% accuracy) and midtreatment (47.2%
accuracy) ratings did not exceed chance levels. Patients who had used hypnotic
drugs prior to this trial were more accurate in their judgments of treatment
conditions than those without prior exposure. The findings raise an important
issue about the internal validity of the double-blind strategy, which may in
fact be only a single-blind procedure.
DE Descriptors:
Aged; Benzodiazepines/ae [Adverse Effects]; *Benzodiazepines/tu [Therapeutic
Use]; *Double-Blind Method; Female; Human; Male; Middle Aged; Perception;
*Randomized Controlled Trials; *Sleep Initiation and Maintenance Disorders/dt
[Drug Therapy];
AN 8552900
AU Shih WJ, Gould AL
TI Re-evaluating
design specifications of longitudinal clinical trials without unblinding when the key response is rate of
change.
IN Merck
Research Laboratories,
SO Statistics
in Medicine.
14(20):2239-48, 1995 Oct 30.
PT Publication
Type: Journal Article
AB The
design of clinical trials often requires knowledge of quantities such as
between- and within subject variances about which only imprecise information exists.
To provide assurance that the study has the desired power to
detect a minimum clinically meaningful difference between treatment groups.
Gould, Gould and Shih, and Shih have recommended obtaining relevant information
from the trial at an interim stage without unblinding. Wittes and Brittain provided a
similar recommendation, but viewed the portion up to the interim stage as an
(internal) pilot study and required unblinding. This paper considers the problem
of re-evaluating the design specifications in longitudinal clinical trials when
the key response is the rate of change (slope). The proposed method aims to
re-evaluate the sample size and study duration in a way that maintains the
trial's blinding,
using an EM algorithm. Simulation results show that the effect on type I error
rate in negligible, but the potential gain in power can be substantial. The
procedure is simple to use in practice, as it does not unblind patients' treatment
identifications, and, since it does not unveil the relative efficacy of
treatments, it fulfils the requirement of a valid 'administrative' (interim)
analysis.
DE Descriptors:
Algorithms; Analysis of Variance; Computer Simulation; *Double-Blind
Method; Human; *Longitudinal Studies; *Randomized Controlled Trials/mt
[Methods]; Reproducibility of Results; Sample Size; *Single-Blind
Method; Time Factors
AN 8135885
AU Hogel J, Walach H, Gaus W
TI Change-to-Open-Label
Design. Proposal and discussion of a new design for clinical parallel-group
double-masked trials.
IN Universitat Ulm, Klinische Dokumentation, Fed. Rep. of
SO Arzneimittel-Forschung. 44(1):97-9, 1994 Jan.
PT Publication
Type: Journal Article
AB The
"Change-to-Open-Label Design" (COLA-design) is proposed to overcome
some of the ethical and organizational problems of the usual double-masked
design in certain situations while preserving its scientific rigor. Patients
are randomized on a doubled-masked basis into treatment groups. During the
trial the patient or the treating physician may ask for a change from the masked
treatment to any open-label treatment of their choice (experimental or not), if
the masked
treatment is thought to be unsatisfactory. It seems to be easier to obtain a
patient's informed consent to participate in placebo controlled double-masked
trials especially for long term studies. The main outcome variable in
COLA-design is the time until a patient demands for such a change.
"Survival analysis" is a powerful statistical method to evaluate this
outcome variable. Even patients lost from observation can be included in the
evaluation: they still deliver censored outcome values. Evidently, in trials
with a COLA-design the patient's personal impression of the therapy is the most
important factor in its assessment. Therapeutical success is mingled with
undesirable effects into the outcome measure; therefore this design is
especially applicable to investigate treatments supposed to increase quality of
life.
DE Descriptors:
*Double-Blind
Method; Drug Therapy/ae [Adverse Effects]; Human; Patient Satisfaction;
Physicians; Quality Control; *Randomized Controlled Trials; *Research Design
AN 7906321
AU Anonymous
TI Blinded
by science.[see comment][comment].
SO Lancet. 343(8897):553-4, 1994 Mar 5.
CM Comment
in: Lancet. 1994 Apr 23;343(8904):1040; PMID: 7909070,
Comment on: Lancet. 1994 Mar 5;343(8897):568-71; PMID:
7906329
PT Publication
Type: Comment; Editorial
DE Descriptors:
Aged; *Beds; Control Groups; *Decubitus Ulcer/pc [Prevention & Control];
*Double-Blind
Method; Human; Randomized Controlled Trials; Research Subjects
AN 7968033
AU Kleijnen J, de Craen AJ, van Everdingen J, Krol L
TI Placebo effect in double-blind clinical trials: a review of interactions
with medications. [Review] [18 refs]
IN Department
of Clinical Epidemiology and Biostatistics,
SO Lancet. 344(8933):1347-9, 1994 Nov 12.
PT Publication
Type: Journal Article; Review; Review, Academic
DE Descriptors:
*Double-Blind
Method; Human; Informed Consent; *Placebo Effect; *Randomized Controlled Trials
AN 8290055
AU Noseworthy JH, Ebers GC, Vandervoort MK, Farquhar RE, Yetisir E,
Roberts R
TI The
impact of blinding on the results of a
randomized, placebo-controlled multiple sclerosis clinical trial.
IN Department
of Neurology, Mayo Clinic and Foundation,
SO Neurology. 44(1):16-20, 1994 Jan.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB In
the randomized, placebo-controlled, physician-blinded Canadian cooperative
trial of cyclophosphamide and plasma exchange, neither active treatment
regimens (group I: i.v. cyclophosphamide and prednisone; group II: weekly
plasma exchange, oral cyclophosphamide, and prednisone) were superior to
placebo (group III: sham plasma exchange and placebo medications) using the blinded,
evaluating neurologists' assessments of disease course (primary analysis). All
patients were examined by both a blinded and an unblinded neurologist at each
assessment in this trial. We compared the blinded and unblinded neurologists'
judgment of treatment response and analyzed the clinical behavior of patients
who correctly guessed their treatment. The unblinded (but not the blinded) neurologists' scores
demonstrated an apparent treatment benefit at 6, 12, and 24 months for the
group II patients (not group I or placebo; p < 0.05, two-tailed). There were
no significant differences in the time to treatment failure or in the
proportions of patients improved, stable, or worse between the group II and
group III patients who correctly guessed their treatment assignments and those
who did not. Physician blinding prevented an erroneous conclusion
about treatment efficacy (false positive, type 1 error).
DE Descriptors:
Comparative Study; Cyclophosphamide/tu [Therapeutic Use]; *Double-Blind
Method; Human; *Multiple Sclerosis/th [Therapy]; *Physicians; Placebos; Plasma
Exchange; Prednisone/tu [Therapeutic Use]; *Single-Blind Method; Support,
Non-U.S. Gov't
AN 8501455
AU Fisher S, Greenberg RP
TI How sound is the double-blind design for evaluating psychotropic drugs?. [Review] [42 refs]
IN Department
of Psychiatry, State University of
SO Journal
of Nervous & Mental Disease. 181(6):345-50, 1993 Jun.
PT Publication
Type: Journal Article; Review; Review, Tutorial
AB Sufficient
data have accumulated to raise serious doubts about the integrity of the double-blind
design that is presumed to shield psychotropic drug trials from bias and
expectations. A major deficit in most drug trials has been the use of inert
rather than active placebos. The deficiencies of the double-blind
paradigm call for a questioning stance with respect to previous studies of
psychotropic drug efficacy. Various possible ways of strengthening the double-blind
paradigm are reviewed. [References: 42]
DE Descriptors:
*Clinical Trials/st [Standards]; *Double-Blind Method; Human; Placebos; *Psychotropic
Drugs/tu [Therapeutic Use]
AN 7870914
AU Kirsch I, Rosadino MJ
TI Do double-blind studies with informed consent yield
externally valid results? An empirical test.
IN Department
of Psychology,
SO Psychopharmacology. 110(4):437-42, 1993.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB Subjective
and physiological effects of caffeine were investigated via a 3 x 2 x 3 design
that assessed independent and interactive effects of instructions (told
caffeine versus told no caffeine versus not told whether beverage contained
caffeine), actual beverage content (caffeine versus no caffeine), and time
after ingestion (15, 30, and 45 min). Instructions affected alertness at 15 min
after ingestion. Caffeine increased alertness at 30 min after ingestion and
systolic blood pressure at 30 min and 45 min after ingestion. A highly
significant instruction by drug interaction on tension was obtained at all
measurement points, indicating an increase in tension only among subjects who
knowingly received caffeine. Because people are generally informed of drug
content in non-research settings, these data challenge the external validity of
typical double-blind studies, in which subjects are informed
of the possibility of receiving a placebo as part of the consent procedure.
DE Descriptors:
Adolescent; Adult; *Affect/de [Drug Effects]; Attention/de [Drug Effects];
Blood Pressure/de [Drug Effects]; *Caffeine/pd [Pharmacology]; *Clinical
Trials/mt [Methods]; *Double-Blind Method; Female; Human; *Informed
Consent; Male; Placebos; Pulse/de [Drug Effects]
AN 1443253
AU White K, Kando J, Park T, Waternaux C,
Brown WA
TI Side effects and the "blindability" of clinical drug trials.[see comment].
IN Department
of Psychiatry,
SO American
Journal of Psychiatry. 149(12):1730-1, 1992 Dec.
CM Comment
in: Am J Psychiatry. 1993 Nov;150(11):1759-60; author
reply 1760-1; PMID: 8214202, Comment in: Am J Psychiatry. 1993 Nov;150(11):1760; author reply 1760-1; PMID: 8214203
PT Publication
Type: Journal Article; Multicenter Study
AB A
novel, simple approach to retrospective assessment of "blindability"
was applied to data on outpatients in a controlled, double-blind clinical comparison of
a putative antidepressant, etoperidone, and placebo. A "blind"
evaluator proved capable of discriminating between the active drug and placebo
on the basis of reported side effects alone, raising questions about the true blindness
of the study.
DE Descriptors:
Ambulatory Care; *Antidepressive Agents/ae [Adverse Effects]; Antidepressive
Agents/tu [Therapeutic Use]; Bias (Epidemiology); *Clinical Trials/st [Standards];
Depressive Disorder/dt [Drug Therapy]; *Double-Blind Method; Human;
Placebos; Retrospective Studies; Support, Non-U.S. Gov't; Trazodone/ae [Adverse
Effects]; *Trazodone/aa [Analogs & Derivatives]; Trazodone/tu [Therapeutic
Use]
AN 1490788
AU Fischer W, Haase W, Ruther E, Clarenbach P, Hajak G
TI Problems in performing a
double-blind multicenter study using a
hypnotic in private practice.
IN Rhone-Poulenc
Rorer GmbH,
SO International
Journal of Clinical Pharmacology, Therapy, & Toxicology. 30(11):474, 1992 Nov.
PT Publication
Type: Journal Article
AB 1. The procedure described--the
immediate data transfer and entry system (ITES)--is suitable to improve the
quality of data collected in multicentre studies in private practice. 2. The
results of the study show that regarding influence on sleep quality and daytime
well-being the non-benzodiazepine Z is significantly superior to placebo and
slightly superior to the benzodiazepines F and T. 3. The advantage of Z
treatment is the better daytime well-being after taking the hypnotic for sleep
induction the night before. 4. This study shows that a quality standard equal
to that in clinical practice may be achieved in private practice.
DE Descriptors:
Adolescent; Adult; Aged; *Double-Blind Method; *Family Practice; Female; Human;
Hypnotics and Sedatives/ae [Adverse Effects]; *Hypnotics and Sedatives/tu
[Therapeutic Use]; Male; Middle Aged; *Multicenter Studies; *Randomized
Controlled Trials; *Sleep Disorders/dt [Drug Therapy]; Sleep Disorders/px
[Psychology]
AN 1353838
AU Sacristan JA, Soto J, Alanis A
TI Complacency bias in
clinical trials.
SO Lancet. 340(8815):375, 1992 Aug 8.
PT Publication
Type: Letter
DE Descriptors:
*Bias (Epidemiology); *Clinical Trials/st [Standards]; *Double-Blind
Method; Human; *Motivation; *Research Personnel/px [Psychology]
AN 1793642
AU Charlton BG
TI Medical practice and the
double-blind, randomized controlled trial.[see comment].
SO British
Journal of General Practice. 41(350):355-6, 1991 Sep.
CM Comment
in: Br J Gen Pract. 1991 Dec;41(353):520; PMID:
1807334
PT Publication
Type: Editorial
DE Descriptors:
*Clinical Medicine; *Double-Blind Method; Human; Physician's Role;
Randomized Controlled Trials
AN 2054578
AU Double D
TI Blinding
trials.[see comment][comment].
SO British
Journal of Psychiatry. 158:573-4, 1991 Apr.
CM Comment
in: Br J Psychiatry. 1991 Jul;159:159-60; PMID:
1888966, Comment on: Br J Psychiatry. 1990 Aug;157:300;
PMID: 2224388, Comment on: Br J Psychiatry. 1990 Dec;157:934-5;
PMID: 2136594
PT Publication
Type: Comment; Letter
DE Descriptors:
*Antidepressive Agents/tu [Therapeutic Use]; *Clinical Trials; *Depressive
Disorder/dt [Drug Therapy]; Depressive Disorder/px [Psychology]; *Double-Blind
Method; Human
AN 1888966
AU Newcombe R
TI Double blind acceptance.[comment].
SO British
Journal of Psychiatry. 159:159-60, 1991 Jul.
CM Comment
on: Br J Psychiatry. 1991 Apr;158:573-4; PMID: 2054578
PT Publication
Type: Comment; Letter
DE Descriptors:
Bias (Epidemiology); *Double-Blind Method; Human; Random Allocation;
Research Design/st [Standards]
AN 2002136
AU Margraf J, Ehlers A, Roth WT, Clark DB,
Sheikh J, Agras WS, Taylor CB
TI How "blind" are double-blind
studies?.
IN Philipps-University
Marburg,
SO Journal
of Consulting & Clinical Psychology. 59(1):184-7, 1991 Feb.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB Psychopharmacological
studies usually attempt to eliminate "nonspecific" influences on
outcome by double-blind designs. In a randomized, double-blind
comparison of alprazolam, imipramine, and placebo, the great majority of panic
disorder patients (N = 59) and their physicians were able to rate accurately
whether active drug or placebo had been given. Moreover, physicians could
distinguish between the two types of active drugs. Inasmuch as correct rating
was possible halfway through treatment, concerns about the internal validity of
the double-blind
strategy arise.
DE Descriptors:
Adult; Alprazolam/tu [Therapeutic Use]; Anxiety Disorders/di [Diagnosis];
Anxiety Disorders/dt [Drug Therapy]; *Double-Blind Method; Female; Human;
Imipramine/tu [Therapeutic Use]; Male; Middle Aged; Panic; Placebos;
Psychotherapy; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.
AN 2180531
AU Newcombe RG
TI Double-blind trials.[see
comment][comment].
SO British
Journal of Psychiatry. 156:282, 1990 Feb.
CM Comment
in: Br J Psychiatry. 1990 Aug;157:300; PMID: 2224388,
Comment on: Br J Psychiatry. 1989 Nov;155:700-1; PMID:
2611601
PT Publication
Type: Clinical Trial; Comment; Letter
DE Descriptors:
Clinical Trials; *Double-Blind Method; Human
AN 2224388
AU Double DB
TI Limitations of double-blind trials.[see
comment][comment].
SO British
Journal of Psychiatry. 157:300, 1990 Aug.
CM Comment
in: Br J Psychiatry. 1990 Dec;157:934-5; PMID:
2136594, Comment in: Br J Psychiatry. 1991 Apr;158:573-4;
PMID: 2054578, Comment on: Br J Psychiatry. 1990 Feb;156:282;
PMID: 2180531
PT Publication
Type: Comment; Letter
DE Descriptors:
Bias (Epidemiology); *Clinical Trials/mt [Methods]; *Double-Blind
Method; Human; *Mental Disorders/dt [Drug Therapy]; *Randomized Controlled
Trials/mt [Methods]
AN 2136594
AU Newcombe RG
TI Limitations of double-blind trials.[see
comment][comment].
SO British
Journal of Psychiatry. 157:934-5, 1990 Dec.
CM Comment
in: Br J Psychiatry. 1991 Apr;158:573-4; PMID:
2054578, Comment on: Br J Psychiatry. 1990 Aug;157:300;
PMID: 2224388
PT Publication
Type: Comment; Letter
DE Descriptors:
*Double-Blind
Method; Human; *Psychotropic Drugs/tu [Therapeutic Use]; *Randomized Controlled
Trials
AN 2611601
AU Oxtoby A, Jones A, Robinson M
TI Is your 'double-blind' design truly double-blind?[see comment].
IN
SO British
Journal of Psychiatry. 155:700-1, 1989 Nov.
CM Comment
in: Br J Psychiatry. 1990 Feb;156:282; PMID: 2180531,
Comment in: Br J Psychiatry. 1990 Jul;157:151-2; PMID:
2397355
PT Publication
Type: Journal Article
DE Descriptors:
*Clinical Trials/st [Standards]; *Double-Blind Method; Human; Periodicals/st
[Standards]; Research Design/st [Standards]
AN 2805022
AU
TI Topics
in clinical research. III. The importance of randomized, double-blind
procedures in clinical trials.
IN Division
of Endocrinology and Metabolism,
SO Clinical
Therapeutics.
11(5):565-7, 1989 Sep-Oct.
PT Publication
Type: Journal Article
DE Descriptors:
*Double-Blind
Method; *Pharmacology, Clinical/td [Trends]; Placebos; *Randomized Controlled
Trials; Research Design
RN CAS
Registry number: 0 (Placebos)
AN 2909265
AU Ney PG
TI Double-blinding in clinical trials.
SO CMAJ
Canadian Medical Association Journal. 140(1):15, 1989 Jan 1.
PT Publication
Type: Letter
DE Descriptors:
*Clinical Trials/mt [Methods]; Clinical Trials/st [Standards]; *Double-Blind
Method/st [Standards]; *Drug Evaluation/st [Standards]; Human; *Research
Design/st [Standards]
AN 2723134
AU Munjack DJ, Brown RA, McDowell D, Palmer R
TI Actual medication versus
therapist guesses: in a blind study, how blind is blind?.
SO Journal
of Clinical Psychopharmacology. 9(2):148-9, 1989 Apr.
PT Publication
Type: Letter
DE Descriptors:
*Clinical Trials; *Double-Blind Method; Human; Mental Disorders/dt [Drug
Therapy]; Mental Disorders/px [Psychology]; *Research Design
AN 2668682
AU Allen AD
TI Making moral decisions on a
double-blinded drug trial in progress
without breaking the code: a primer on
posterior analysis.
IN Biomedical
Sciences Division, Algorithms, Inc.,
SO Medical
Decision Making.
9(3):207-16, 1989 Jul-Sep.
PT Publication
Type: Journal Article
AB The
double blinding
of drug trials to prevent bias deprives physicians of information they need in
order to comply with their duty to treat patients and do them no harm. This
ethical dilemma can be ameliorated with a standard statistical method known as
posterior analysis. The clinical researcher can use posterior analysis to
calculate the probability that a patient in a double-blinded drug trial is in the
placebo group, based on the patient's clinical status. The clinician can also
calculate the probability that the drug is safe and efficacious, as compared
with the placebo, without breaking the code.
DE Descriptors:
*Clinical Trials; *Decision Support Techniques; *Double-Blind Method; *Ethics,
Medical; Government Regulation; Human; Nontherapeutic Human Experimentation;
Placebos; Probability; Random Allocation; *Research Design/st [Standards];
Research Subjects; Risk Assessment
AN 3365327
AU Kirsch I, Weixel LJ
TI Double-blind versus deceptive administration of a
placebo.
IN
SO Behavioral
Neuroscience.
102(2):319-23, 1988 Apr.
PT Publication
Type: Clinical Trial; Controlled Clinical Trial; Journal Article
AB Subjects
were given varying doses of a placebo, consisting of decaffeinated coffee, with
double-blind
or deceptive instructions. Deceptive administration simulated clinical
situations in that subjects were led to believe that they were receiving an
active drug. In contrast, subjects in double-blind conditions were aware
that they might receive a placebo. Double-blind and deceptive administration of the
placebo produced different, and in some instances, opposite effects on pulse
rate, systolic blood pressure, and subjective mood. Deceptive administration
produced an increase in pulse rate, whereas double-blind administration did not.
A theoretically predicted curvilinear effect on systolic blood pressure,
alertness, tension, and certainty of having consumed caffeine was confirmed
with deceptive administration, but not with double-blind administration. Double-blind
administration produced curves in the opposite direction on each of these
variables. The effects of the placebo on motor performance varied as a function
of subject's beliefs about the effects of caffeine. These data challenge the
validity of double-blind experimental designs and suggest that
this common method of drug assessment may lead to spurious conclusions.
DE Descriptors:
Adolescent; Adult; *Clinical Trials/mt [Methods]; *Double-Blind Method; Female; Human;
Male; Patient Participation; *Placebos; *Research Design
AN 3816016
AU Moscucci M, Byrne L, Weintraub M, Cox C
TI Blinding,
unblinding, and the placebo effect: an
analysis of patients' guesses of treatment assignment in a double-blind clinical trial.
SO Clinical
Pharmacology & Therapeutics. 41(3):259-65, 1987 Mar.
PT Publication
Type: Journal Article
AB We
administered a questionnaire to assess maintenance of patients' blindness
at the end of a double-blind clinical trial of Osmotic Release Oral
System phenylpropanolamine (PPA) vs. placebo in mild obesity. Seventy-four
percent of placebo participants and 43% of PPA participants guessed their
treatment correctly. Appetite control was the most frequently reported basis
for guessing PPA, even by placebo participants. Lack of adverse drug reactions
was the most frequently reported basis for guessing placebo, even by PPA
participants. Participants receiving either PPA or placebo and guessing PPA
lost more weight, had less diet difficulty, and had more adverse drug reactions
than had participants receiving either PPA or placebo and guessing placebo.
Although blindness
was probably maintained in the PPA group, the placebo group seems to have been,
at least at the study's end, unblinded. These results suggest that in
double-blind
studies, differences in outcome or incidence of adverse drug reactions may act
as unblinding
factors.
DE Descriptors:
Body Weight/de [Drug Effects]; *Clinical Trials; Delayed-Action Preparations;
Diet, Reducing; *Double-Blind Method; Human; Obesity/dt [Drug
Therapy]; Phenylpropanolamine/ae [Adverse Effects]; Phenylpropanolamine/tu
[Therapeutic Use]; *Placebos; Questionnaires; Random Allocation; *Research
Design; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.
AN 3641026
AU Ney PG, Collins C, Spensor C
TI Double blind: double talk or are there ways to do better
research.
SO Medical
Hypotheses.
21(2):119-26, 1986 Oct.
PT Publication
Type: Journal Article
AB In
an attempt to counteract placebo effects, scientists studying the effectiveness
of medication often use the 'double blind' trial. Unfortunately, in less than 5%
of the studies reported in major medical and psychiatric journals was there a
check to determine whether patients and observers were blind. Between 1972 and 1983
there was increasing reliance on active placebos which attempt to mimic the
effects of the medication. It is unlikely however, that patients are not aware
of significantly different physiologic changes within them resulting from the
different chemicals. Whenever a physician informs a subject that they may be on
placebo or active treatment medication, they will spend much time in trying to
guess when they are taking which. In these situations Philip's paradox will
apply. This states that the more potent a therapeutic variable the less likely
its efficacy can be 'proven' in a double-blind study. One can only 'prove' that
medication is no more effective than placebo. To have a truly blind
procedure, the active placebo must have identical physiological effects to
those of the medication being studied. We are now using the patient's and the
observer's awareness of changes as useful information to obtain: a guess
factor, the percentage of correct guesses whether the patient is on medication
or placebo; a direction factor, whether the patient considers the change
beneficial or detrimental; an attributional factor, whether the change is
considered to result from medication or other intervening variables. This
information is usually reliable and can be analyzed with the usual statistical
procedures.
DE Descriptors:
Attitude to Health; Awareness; *Double-Blind Method; Ethics, Medical; Human;
Patients/px [Psychology]; Physicians/px [Psychology]; *Placebos; *Research
Design
AN 3538107
AU Rabkin JG, Markowitz JS, Stewart J, McGrath
P,
TI How blind is blind?
Assessment of patient and doctor medication guesses in a placebo-controlled
trial of imipramine and phenelzine.
SO Psychiatry
Research.
19(1):75-86, 1986 Sep.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB The
purpose of the double blind is to protect the internal validity of a
clinical trial by preventing knowledge of treatment conditions from influencing
outcome or its assessment. We studied medication guesses of 137 depressed
patients and/or their doctors at the end of a 6-week randomized trial of
placebo, imipramine, and phenelzine. Overall, 78% of the patients and 87% of
the doctors correctly distinguished between placebo and active medication.
Clinical outcome, treatment condition, and their interaction each contributed
to guessing accuracy, while medication experience and side effects assessed
only in week 6 did not. Accuracy was high, however, even when cases were
stratified for clinical outcome, indicating that other cues were available to
the patients and doctors. These may include patterns and timing of side effects
and clinical response not detectable in this end-point analysis.
DE Descriptors:
Adolescent; Adult; Clinical Trials; Comparative Study; Cues; *Depressive
Disorder/dt [Drug Therapy]; *Double-Blind Method/st [Standards]; Human;
Imipramine/ae [Adverse Effects]; *Imipramine/tu [Therapeutic Use]; Middle Aged;
Patients/px [Psychology]; Phenelzine/ae [Adverse Effects]; *Phenelzine/tu
[Therapeutic Use]; Physicians/px [Psychology]; Random Allocation; *Research
Design/st [Standards]; Support, U.S. Gov't, P.H.S.
AN 4074613
AU Jones AL, Grainger SL, Smith SE
TI The
elimination of treatment predictability in double-blind
studies.
SO British
Journal of Clinical Pharmacology. 20(4):428-9, 1985 Oct.
PT Publication
Type: Journal Article
DE Descriptors:
*Double-Blind
Method; Human; Pharmaceutical Preparations/ae [Adverse Effects]; Placebos;
*Research Design
AN 1985112015
AU Buckalew LW
TI Methodological
issues in drug assessment research.
IN Aerospace
Medical Research Branch, USAF
SO Drug
Development Research. Vol. 5(2)(pp 103-110), 1985.
PT Publication
Type: Journal
AB Increased
sensitivity to methodological issues in drug assessment research is needed in
light of challenges to research design, conduct, and outcomes. Major issues
presented include (a) the nature and adequacy of placebo controls, (b) problems
in maintaining the integrity of 'blind' conditions, and (c) the
potential design-compromising effects of informed consent. The necessity of
true matching placebos, particularly concerning physical/perceptual
characteristics and the ability to produce transitory changes in subjects, was
stressed. Though the double-blind condition has conceptual integrity,
the operation of drug and placebo side effects and associated guess bias may
confound research results. Use of a triple-blind condition and addition of a
drug-disguised group is suggested. Last, the issue of informed consent and its
implications for the integrity of drug research is a problem
deserving more attention.
DE Descriptors:
*Placebo; *Control System; *Double Blind Procedure; *Drug Determination; *Drug
Efficacy; *Drug Therapy; Priority Journal; Therapy; Review; Human;
Psychological Aspect; Controlled Study
AN 3974051
AU Byington RP, Curb JD, Mattson ME
TI Assessment
of double-blindness at the conclusion of
the beta-Blocker Heart Attack Trial.
SO JAMA. 253(12):1733-6, 1985 Mar 22-29.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB At
the conclusion of a double-blinded, randomized clinical trial of
propranolol hydrochloride, but before unblinding, the patients and clinic personnel were
asked to guess the treatment group assignment of each patient. While 79.9% of
the patients receiving propranolol correctly identified their treatment group
assignment, 57.2% of the patients receiving placebo incorrectly guessed that
they were also in the propranolol group. No specific mechanism was identified
to explain why more patients receiving propranolol were better able to guess
their group assignment. Clinic physicians correctly identified the group
assignment of 69.9% of the patients receiving propranolol and 68.8% of the
patients receiving placebo. Clinic coordinators correctly identified the group
assignment of 67.1% of the patients receiving propranolol and 70.6% of the
patients receiving placebo. For clinic personnel, heart rate level and heart
rate change seem to be the mechanisms employed to identify their patients'
treatment assignment.
DE Descriptors:
Adult; Aged; *Clinical Trials/mt [Methods]; Control Groups; *Double-Blind
Method/st [Standards]; Female; Heart Rate/de [Drug Effects]; Human; Male;
Middle Aged; *Myocardial Infarction/dt [Drug Therapy]; *Propranolol/tu
[Therapeutic Use]; Random Allocation; *Research Design/st [Standards];
Socioeconomic Factors;
AN 2861298
AU Spodick DH
TI Double-blind as a BHAT.
SO JAMA. 254(6):755, 1985 Aug 9.
PT Publication
Type: Letter
DE Descriptors:
*Adrenergic beta-Antagonists/tu [Therapeutic Use]; *Double-Blind Method; Human;
*Myocardial Infarction/dt [Drug Therapy]; *Research Design
AN 3998203
AU Hughes JR, Krahn D
TI Blindness and the validity of the double-blind procedure.
SO Journal
of Clinical Psychopharmacology. 5(3):138-42, 1985 Jun.
PT Publication
Type: Clinical Trial; Journal Article; Randomized Controlled Trial
AB This
article describes a method for assessing whether the blindness of a double-blind
study is maintained and, if not, whether failure to maintain blindness
could have invalidated the results of the study. The benefit of using the
method is illustrated in a study of the effect of nicotine gum on the tobacco
withdrawal syndrome. In that study, many subjects were able to identify which
drug they received; however, a drug effect was present among subjects who
correctly identified their drug, among subjects who incorrectly identified
their drug, and among subjects who could not tell which drug they received.
Thus, failure to maintain blindness could not have invalidated the
results of the study. The authors believe double-blind studies should
routinely assess blindness, and they recommend their method as
a simple and easy way to assess blindness.
DE Descriptors:
Chewing Gum; *Double-Blind Method/st [Standards]; Human;
Nicotine/ad [Administration & Dosage]; Random Allocation; *Research
Design/st [Standards]; Smoking/pc [Prevention & Control]; Substance
Withdrawal Syndrome/dt [Drug Therapy]; Support, Non-U.S. Gov't
AN 6468216
AU Bonfils S, Baron JH, Blum A
TI Uncontrolled factors in
controlled trials of peptic ulcer.
SO Digestive
Diseases & Sciences. 29(9):858-61, 1984 Sep.
PT Publication
Type: Journal Article
DE Descriptors:
*Anti-Ulcer Agents/tu [Therapeutic Use]; *Clinical Trials/mt [Methods];
*Double-Blind
Method; Human; Patients/px [Psychology]; Peptic Ulcer/dt [Drug Therapy];
Physician-Patient Relations; Placebos; *Research Design
AN 6846655
AU Barsa JA
TI More
on the fallibility of the double-blind.
SO American
Journal of Psychiatry. 140(6):820-1, 1983 Jun.
PT Publication
Type: Letter
DE Descriptors:
*Double-Blind
Method/st [Standards]; Human; Informed Consent; Psychiatry; *Research Design/st
[Standards]
AN 6753613
AU Brownell KD, Stunkard AJ
TI The double-blind in danger: untoward consequences of informed
consent.
SO American
Journal of Psychiatry. 139(11):1487-9, 1982 Nov.
PT Publication
Type: Clinical Trial; Journal Article
AB Patients
and physicians correctly identified medication assignments in 70% of the cases
in a double-blind
trial of an appetite suppressant. The breach of the double-blind design may have had
therapeutic consequences; correct identification was associated with favorable
outcome. These findings suggest that requirements for describing the side
effects of medications to patients before they give informed consent may help
them guess which medication they receive and thus may influence the integrity
of double-blind
studies and the results of controLled trials.
DE Descriptors:
Adult; Aged; Body Weight; Clinical Trials; Dizziness/ci [Chemically Induced];
*Double-Blind
Method/st [Standards]; Fatigue/ci [Chemically Induced]; Female; Fenfluramine/ae
[Adverse Effects]; Human; *Informed Consent; Middle Aged; Placebos; *Research
Design/st [Standards]; Risk Assessment;
AN 7127995
AU Howard J,
TI How blind was the patient blind
in AMIS?.
SO Clinical
Pharmacology & Therapeutics. 32(5):543-53, 1982 Nov.
PT Publication
Type: Journal Article
AB The
Aspirin Myocardial Infarction Study (AMIS) was a double-blind placebo-controlled
trial to test the effect of aspirin on the survival of 4524 people who had experienced
a prior heart attack. Shortly before their closeout visits, 400 of the
participants were randomly selected to be interviewed concerning their
perceptions of their treatment assignments; 380 were actually interviewed. A
bare majority (52)% correctly identified their study
therapy, 28% mistakenly named the alternative treatment, 13% declined to guess,
and 7% specified extraneous substances. According to the proposed formula for
evaluating the patient blind, only 24% of the sample made
"informed" guesses regarding their therapy, while the remainder
guessed in an uninformed way or not at all. Those who tested their capsules
(usually be taste) showed proportionately more correct responses than the
nontesters. Correctness also varied with the reasons for the subjects' guesses
(e.g., side effects). Among the sample as a whole, most people were only
moderately or less than moderately certain their guess was correct. Even among
those who were in fact correct, only 18% were absolutely certain of their choice.
DE Descriptors:
Adult; Aged; Aspirin/tu [Therapeutic Use]; *Double-Blind Method; Female; Human;
Male; Middle Aged; Myocardial Infarction/dt [Drug Therapy]; Perception;
*Placebos; Random Allocation; *Research Design; Support, U.S. Gov't, P.H.S.
AN 7160189
AU Halperin M, Lan KK, Ware JH, Johnson NJ, DeMets DL
TI An
aid to data monitoring in long-term clinical trials.
SO Controlled
Clinical Trials.
3(4):311-23, 1982 Dec.
PT Publication
Type: Journal Article
DE Descriptors:
*Clinical Trials/st [Standards]; *Double-Blind Method; Human; Mortality; *Research
Design; *Statistics;
AN 6789934
AU Gore SM
TI Assessing
clinical trials- double-blind trials.
SO British
Medical Journal Clinical Research Ed..
283(6284):122-4, 1981 Jul 11.
PT Publication
Type: Journal Article
DE Descriptors:
Attitude of Health Personnel; *Clinical Trials/mt [Methods]; *Double-Blind
Method; *Research Design; Statistics
AN 6105316
AU Friedman L, Passamani E, May G, Furberg C, Friedewald W
TI Placebo controlled double blind trials.
SO Lancet. 2(8186):147-8, 1980 Jul 19.
PT Publication
Type: Letter
DE Descriptors:
*Clinical Trials; *Double-Blind Method; Drug Administration Schedule;
*Drug Therapy; Human; Placebos; *Research Design
AN 618704
AU Zifferblatt SM, Wilbur CS
TI A
psychological perspective for double-blind
trials.
SO Clinical
Pharmacology & Therapeutics. 23(1):1-10, 1978 Jan.
PT Publication
Type: Journal Article
AB Blind
breaking
is likely to occur in a long-term clinical trial involving subjects at risk.
Double-blind
conditions require subjects to live with ambiguity regarding their health
status. It is unrealistic to expect them to tolerate this ambiguity over an
extended period of time. A logical step for a subject is to break
the blind
and surreptitiously seek the best medical care available. Moreover, the staff
assigned to monitor protocol adherence may further contribute to blind
breaking
because of ambiguity regarding their proper clinical role. Several steps are
recommended to manage blind breaking within a trial, including improving the
quality of medical care, more rigorous screening procedures, and maintaining a
clinical environment that promotes accurate disclosure of blind breaking.
DE Descriptors:
Attitude of Health Personnel; *Double-Blind Method/px [Psychology]; Double-Blind
Method/st [Standards]; Human; Patient Compliance; *Research Design; Research
Personnel
AN 368823
AU Reinharez D
TI [Errors
of the placebo test]. [French]
SO Phlebologie. 31(4):313-20, 1978 Oct-Dec.
PT Publication
Type: Clinical Trial; Controlled Clinical Trial; Journal Article
AB The
difficulties inherent in clinical experimentation in phlebology, stem from the
fact that they concern highly subjective functional problems, and are thus
difficult to measure. The answer to these difficulties seems to be found in the
use of the double blind method. This method, however, contains
numerous causes of errors in phlebology, since in order to be mathematically
applied to computer use, it is too sketchy and does not take into account many
additional factors, incidental parameters and unfavorable coincidences related
either to chronobiology (weather, seasonal changes), to hormonal problems
(periods of the cycle, pregnancies, contraception, menopause), to the environment
(professional posture, ground heat, periods of vacation or work), or associated
diseases (neuro-vegetative and rheumatic disorders, excessive weight, metabolic
disorders), etc. It seems that in such cases, wide experimentation, with a very
critical clinician, who attributes the improvement obtained to the drugs
prescribed only when left with no other possibility and after having eliminated
all the coincidental factors, gives results closer to reality than double blind
experiments, behind whose pseudo-scientific appearance lies
a sketchiness that is the cause of numerous errors.
DE Descriptors:
Clinical Trials; Diagnostic Errors; *Double-Blind Method; Drug
Evaluation; English Abstract; Environment; Hormones; Human; *Placebos;
*Research Design; Time Factors
AN 334685
AU Modestin J, Hodel J
TI [How blind is a double-blind
trial really? Validity of controlled investigations].
[German]
SO International
Pharmacopsychiatry. 12(3):129-36, 1977.
PT Publication
Type: Clinical Trial; Controlled Clinical Trial; Journal Article
AB During
a double blind
trial lasting 4 weeks (Diazepam versus Loxapin), two investigators tried to
identify the given drug prematurely. Only the more experienced
investigator was able to identify the two drugs (p = 0.01). His judgement was
based neither on observation of side-effects nor on a clinical improvement but
apparently on a summary of particular subtle effects, the cognition of which
requires a specific experience. The use of an adequate comparative drug instead
of a placebo in a double blind study does not completely prevent a premature
decoding
but should reduce this risk and therefore increase the validity of the method.
DE Descriptors:
Anxiety/dt [Drug Therapy]; Clinical Trials; Comparative Study; Diazepam/tu
[Therapeutic Use]; *Double-Blind Method/st [Standards]; Drug Evaluation;
English Abstract; Human; Loxapine/tu [Therapeutic Use]; *Research Design/st
[Standards]