Informing participants of allocation to placebo at trial closure: postal survey.

Abstract:

OBJECTIVES:To assess whether and how investigators of placebo controlled randomised trials inform participants of their treatment allocation at trial closure and to assess barriers to feedback. DESIGN:Postal survey with a semistructured questionnaire. PARTICIPANTS:All investigators who published a placebo controlled randomised trial in 2000 in five leading medical journals, and a random sample of 120 trials listed in the national research register database. MAIN OUTCOME MEASURES:Number of investigators who informed participants of their treatment allocation at trial closure, methods for delivering the information, and barriers to unmasking treatment. RESULTS:45% of investigators informed either all or most participants of their treatment allocation, and 55% did not inform any participant or only informed those who asked. The main reasons for not informing participants were that the investigators never considered this option (40%) or to avoid biasing results at study follow up (24%). CONCLUSION:Further research is required to examine sensitive ways to communicate treatment information to trial participants.

journal_name

BMJ

authors

Di Blasi Z,Kaptchuk TJ,Weinman J,Kleijnen J

doi

10.1136/bmj.325.7376.1329

keywords:

subject

Has Abstract

pub_date

2002-12-07 00:00:00

pages

1329

issue

7376

eissn

0959-8138

issn

1756-1833

journal_volume

325

pub_type

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