Visual analogue scales for endoscopic evaluation of nonsteroidal anti-inflammatory drug-induced mucosal damage in the stomach and duodenum.

The use of visual analogue scales in the evaluation of mucosal lesions may reduce sample size requirements in clinical trials, but they may be complex to use, and adding guide points may reduce their informative value. We found that two investigators with differing levels of endoscopic experience reached comparable conclusions in 4 clinical trials (738 scores), and their scores were highly correlated, with similar dispersion characteristics. With guide texts along the scales, thus avoiding points on the actual scales, no tendency towards accumulation was seen in 1449 scores. These results encourage the use of visual analogue scales in endoscopic studies.