Article

OBJECTIVE: To assess systematically the reporting of sample size calculation in
randomized controlled trials (RCTs) in 5 leading journals in the field of
physical medicine and rehabilitation (PM&R).
The data source was
full reports of RCTs in 5 leading PM&R journals (Journal of Rehabilitation
Medicine, Archives of Physical Medicine and Rehabilitation, American Journal of
Physical Medicine and Rehabilitation, Clinical Rehabilitation, and Disability and
Rehabilitation) between January and December of 1998 and 2008. Articles were
identified in Medline. STUDY SELECTION: A total of 111 articles met our inclusion
criteria, which include RCTs of human studies in the 5 selected journals. DATA
EXTRACTION: Sample size calculation reporting and trial characteristics were
collected for each trial by independent investigators. DATA SYNTHESIS: In 2008,
57.3% of articles reported sample size calculation as compared with only 3.4% in
1998. The parameters that were commonly used were a power of 80% and alpha of 5%.
Articles often failed to report effect size or effect estimates for sample size
calculation. Studies reporting sample size calculation were more likely to
describe the main outcome and to have a sample size greater than 50 subjects. The
study outcome (positive vs negative) was not associated with the likelihood of
sample size reporting. Trial characteristics of the 2 periods (1998 vs 2008) were
similar except that in 1998 there were more negative studies compared with 2008.
CONCLUSIONS: Although sample size calculation reporting has improved dramatically
in 10 years and is comparable with other fields in medicine, it is still not
adequate given current publication guidelines.
CI - Copyright (c) 2011 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.
evidence based medicine; EBM ;
Medecine physique et réadaptation; MPR;
Essais cliniques randomisés ; Revue de la littérature

Langue : ANGLAIS