Quality assessment of randomized controlled trials of low-osmolality versus high-osmolality contrast media

Because of the significance of conclusions drawn from randomized controlled trials (RCTs) comparing the benefits of low-osmolality versus high-osmolality contrast media, the authors employed a standardized instrument to evaluate the quality of 100 RCTs comparing these media. The mean +- standard deviation quality score was 38.9 +- 11.8 (maximum possible score = 100). A majority of RCTs received high scores on three of the dimensions of quality that we rated; intermediate scores on seven dimensions; and low scores on nine dimensions. Therefore, it is difficult to interpret the results of these RCTs. RCTs comparing contrast media should be performed with greater attention paid to basic elements of study design