Reporting on blinding in trial protocols and corresponding publications was often inadequate but rarely contradictory

TY - JOUR

T1 - Reporting on blinding in trial protocols and corresponding publications was often inadequate but rarely contradictory

AU - Hróbjartsson, Asbjørn

AU - Pildal, Julie

AU - Chan, An-Wen

AU - Haahr, Mette T

AU - Altman, Douglas G

AU - Gøtzsche, Peter C

N1 - Keywords: Clinical Protocols; Double-Blind Method; Humans; Periodicals as Topic; Publishing; Randomized Controlled Trials as Topic; Research Design

PY - 2009

Y1 - 2009

N2 - OBJECTIVE: To compare the reporting on blinding in protocols and articles describing randomized controlled trials. STUDY DESIGN AND SETTING: We studied 73 protocols of trials approved by the scientific/ethical committees for Copenhagen and Frederiksberg, 1994 and 1995, and their corresponding publications. RESULTS: Three out of 73 trials (4%) reported blinding in the protocol that contradicted that in the publication (e.g., "open" vs. "double blind"). The proportion of "double-blind" trials with a clear description of the blinding of participants increased from 11 out of 58 (19%) when based on publications alone to 39 (67%) when adding the information in the protocol. The similar proportions for the blinding of health care providers were 2 (3%) and 22 (38%); and for the blinding of data collectors, they were 8 (14%) and 14 (24%). In 52 of 58 publications (90%), it was unclear whether all patients, health care providers, and data collectors had been blinded. In 4 of the 52 trials (7%), the protocols clarified that all three key trial persons had been blinded. CONCLUSIONS: The reporting on blinding in both trial protocols and publications is often inadequate. We suggest developing international guidelines for the reporting of trial protocols and public access to protocols.

AB - OBJECTIVE: To compare the reporting on blinding in protocols and articles describing randomized controlled trials. STUDY DESIGN AND SETTING: We studied 73 protocols of trials approved by the scientific/ethical committees for Copenhagen and Frederiksberg, 1994 and 1995, and their corresponding publications. RESULTS: Three out of 73 trials (4%) reported blinding in the protocol that contradicted that in the publication (e.g., "open" vs. "double blind"). The proportion of "double-blind" trials with a clear description of the blinding of participants increased from 11 out of 58 (19%) when based on publications alone to 39 (67%) when adding the information in the protocol. The similar proportions for the blinding of health care providers were 2 (3%) and 22 (38%); and for the blinding of data collectors, they were 8 (14%) and 14 (24%). In 52 of 58 publications (90%), it was unclear whether all patients, health care providers, and data collectors had been blinded. In 4 of the 52 trials (7%), the protocols clarified that all three key trial persons had been blinded. CONCLUSIONS: The reporting on blinding in both trial protocols and publications is often inadequate. We suggest developing international guidelines for the reporting of trial protocols and public access to protocols.

U2 - 10.1016/j.jclinepi.2009.04.003

DO - 10.1016/j.jclinepi.2009.04.003

M3 - Journal article

C2 - 19635403

SN - 0895-4356

VL - 62

SP - 967

EP - 973

JO - Journal of Clinical Epidemiology

JF - Journal of Clinical Epidemiology

IS - 9

ER -