TY - JOUR
T1 - An observational study found that authors of randomized controlled trials frequently use concealment of randomization and blinding, despite the failure to report these methods
AU - Devereaux, P. J.
AU - Choi, Peter T.L.
AU - El-Dika, Samer
AU - Bhandari, Mohit
AU - Montori, Victor M.
AU - Schünemann, Holger J.
AU - Garg, Amit X.
AU - Busse, Jason W.
AU - Heels-Ansdell, Diane
AU - Ghali, William A.
AU - Manns, Braden J.
AU - Guyatt, Gordon H.
N1 - Funding Information:
P.J.D. is supported by a Canadian Institutes of Health Research, Senior Research Fellowship Award. P.T.-L.C. is supported by a Vancouver Coastal Health Research Institute Mentored Clinician Scientist Award. M.B. is supported by a Department of Clinical Epidemiology and Biostatistics, McMaster University, Clinical Scientist Fellowship Award. V.M.M. is a Mayo Foundation Scholar. J.B. is supported by a Canadian Institutes of Health Research Fellowship Award. A.X.G. is supported by a Canadian Institutes of Health Research Clinician Scientist Training Award. W.A.G. is supported by a Population Health Investigator Award from the Alberta Heritage Foundation for Medical Research and holds a Government of Canada Research Chair in health services research. B.J.M. is supported by a Canadian Institutes of Health Research New Investigator Award.
PY - 2004/12
Y1 - 2004/12
N2 - Readers of randomized controlled trials (RCTs) commonly assume that what was not reported did not occur. We undertook an observational study to determine whether concealment of randomization or blinding was used in RCTs that failed to report these bias-reducing strategies. We recorded the reporting of concealment of randomization and blinding in 105 RCTs. We subsequently contacted the authors and determined if they had used these methodological safeguards. We successfully obtained data from 98 authors. The authors in the full-text publications of these 98 RCTs failed to report the presence or absence of concealment of randomization in 55%, and the blinding status of participants in 26%, health care providers in 64%, data collectors in 84%, outcome assessors in 83%, and data analysts in 96%. In direct contact, authors frequently reported concealing randomization (96%; 95% confidence interval CI = 87-100%), blinding participants (20%; 95% CI = 7-41%), blinding health care providers (65%; 95% CI = 52-77%), blinding data collectors (65%; 95% CI = 53-75%), blinding outcome assessors (79%; 95% CI = 69-87%), and blinding data analysts (50%; 95% CI = 40-60%), despite not reporting the use of these methodological safeguards in their publications. Readers should not assume that bias-reducing procedures not reported in an RCT did not occur.
AB - Readers of randomized controlled trials (RCTs) commonly assume that what was not reported did not occur. We undertook an observational study to determine whether concealment of randomization or blinding was used in RCTs that failed to report these bias-reducing strategies. We recorded the reporting of concealment of randomization and blinding in 105 RCTs. We subsequently contacted the authors and determined if they had used these methodological safeguards. We successfully obtained data from 98 authors. The authors in the full-text publications of these 98 RCTs failed to report the presence or absence of concealment of randomization in 55%, and the blinding status of participants in 26%, health care providers in 64%, data collectors in 84%, outcome assessors in 83%, and data analysts in 96%. In direct contact, authors frequently reported concealing randomization (96%; 95% confidence interval CI = 87-100%), blinding participants (20%; 95% CI = 7-41%), blinding health care providers (65%; 95% CI = 52-77%), blinding data collectors (65%; 95% CI = 53-75%), blinding outcome assessors (79%; 95% CI = 69-87%), and blinding data analysts (50%; 95% CI = 40-60%), despite not reporting the use of these methodological safeguards in their publications. Readers should not assume that bias-reducing procedures not reported in an RCT did not occur.
KW - Blinding
KW - CONSORT statement
KW - Randomization
KW - Randomized controlled trial
KW - Research methodology
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U2 - 10.1016/j.jclinepi.2004.03.017
DO - 10.1016/j.jclinepi.2004.03.017
M3 - Article
C2 - 15617948
AN - SCOPUS:19944411435
SN - 0895-4356
VL - 57
SP - 1232
EP - 1236
JO - Journal of Clinical Epidemiology
JF - Journal of Clinical Epidemiology
IS - 12
ER -