Radiology, Vol 170, 377-380, Copyright © 1989 by Radiological Society of North America
Quality assessment of randomized controlled trials of contrast media
NR Powe, ML Kinnison and EP Steinberg
Johns Hopkins Program for Medical Technology and Practice Assessment, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Numerous randomized controlled trials (RCTs) have been conducted to define
the relative benefits of low-osmolality contrast media (LOM) and
high-osmolality contrast media (HOM). Because of the clinical and economic
significance of the conclusions drawn from these RCTs, the authors used a
standardized instrument to evaluate the quality of study design and data
analysis of 100 RCTs published between 1982 and 1987 that compared LOM and
HOM. The mean quality score (+/- standard deviation) was 39 +/- 12 (maximum
possible score, 100). The largest number of patients studied in any RCT was
435; the smallest was five. A majority of the RCTs received high scores on
three attributes of quality, intermediate scores on seven, and low scores
on nine. These results underscore the difficulty of designing, performing,
analyzing, and reporting high-quality RCTs. Nevertheless, limitations in
study design and data analysis need to be considered when interpreting
results of these RCTs. Future RCTs comparing LOM and HOM should be
performed with greater attention to basic elements of good study design and
data analysis.
