Turning a blind eye: the success of blinding reported in a random sample of randomised, placebo controlled trials

Fergusson, Dean; Glass, Kathleen Cranley; Waring, Duff R.; Shapiro, Stan

doi:10.1136/bmj.37952.631667.ee

Cited by 201 publications

(129 citation statements)

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“…Lack of information on the methods used to retrieve and assess the validity of the primary studies was identified as the main deficiency. Factors associated with bias in RCTs include lack of concealment of randomization; lack of blinding of physicians, patients, outcome assessors and data analysts, and failure to report reasons for excluding patients , Juni et al 1999, Moher et al 1999b, Schulz 2000, Bhandari et al 2002a, Fergusson et al 2004. Several checklists and scales have been proposed for the assessment of study quality, which include those factors (Moher et al 1995).…”

Section: Was the Methodological Quality Of The Studies Assessed?mentioning

confidence: 99%

How to interpret a meta-analysis and judge its value as a guide for clinical practice

et al. 2007

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Section: Was the Methodological Quality Of The Studies Assessed?mentioning

confidence: 99%

How to interpret a meta-analysis and judge its value as a guide for clinical practice

et al. 2007

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“…perfect, it was more successful than in most randomized, double-blind trials. 31,32 Measurements of urinary sucralose levels suggested a high rate of adherence. Previous trials may have yielded inconsistent results because of small samples, short duration, poor adherence, or lack of individual randomization.…”

Section: Figure 2 Urinary Sucralose Concentrationsmentioning

confidence: 99%

A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children

et al. 2012

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“…Blinding is a cornerstone of randomized clinical trials in drug evaluation (Fergusson, Glass, Waring, & Shapiro, 2004;Gaudino & Herbert, 2005;Hrobjartsson & Gotzsche, 2003. Studies of pharmacotherapies for tobacco dependence have adhered to this tradition.…”

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confidence: 99%

Belief about drug assignment and abstinence in treatment of cigarette smoking using nortriptyline

Hall

Gorecki

Reus

et al. 2007

CNTR

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The purpose of this study was to assess the relationship of beliefs about drug assignment and abstinence status in two treatment studies using nortriptyline hydrochloride as an adjunct to smoking cessation. Smokers (N=345) drawn from two clinical trials were asked at the final follow-up (FFU) at 52-64 weeks whether they believed they had received active or placebo drug; responses were obtained from 76% of the sample (n=262). Biochemically verified abstinence was collected at end of treatment (EOT) and FFU. In both studies, participants were correct in guessing drug assignment.At FFU, belief about drug assignment was not related to abstinence for either active or placebo participants. Participants who received active drug and who were smoking at EOT were more likely to believe they had received placebo than active drug participants who were abstinent at EOT. There was no significant relationship between belief about drug and abstinence status for placebo participants at EOT. Baseline variables did not significantly predict correctness of drug identification. Participants who experienced drug side effects not easily attributable to nicotine withdrawal were more likely to identify their drug assignment as nortriptyline. We conclude that experience during the active treatment period, including side effects and treatment success, may be related to belief about drug assignment, that the field would be well served by at least two assessments of blindness in clinical trials, and that discrepancy between these findings and those studying NRT may be due to differences in dependent variables.3

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Turning a blind eye: the success of blinding reported in a random sample of randomised, placebo controlled trials

Abstract: 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.

Cited by 201 publications

References 21 publications

How to interpret a meta-analysis and judge its value as a guide for clinical practice

How to interpret a meta-analysis and judge its value as a guide for clinical practice

A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children

Belief about drug assignment and abstinence in treatment of cigarette smoking using nortriptyline

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