Designs of colonoscopic adenoma detection trials: more positive results with tandem than with parallel studies - an analysis of studies on imaging techniques and mechanical devices

Abstract

A tandem study is more likely to yield positive results than a simple parallel trial; this may be due to the use of different parameters, variable definitions and methodology, and perhaps also a higher likelihood of bias. Therefore, we suggest to accept positive results of tandem studies only if accompanied by positive results from parallel trials.