Role of endoscopy in nonsteroidal anti-inflammatory drug clinical trials

Endoscopy is a useful tool that can be used to determine the acute or chronic gastrointestinal (GI) toxicity of nonsteroidal anti-inflammatory drugs (NSAIDs) and to confirm outcomes in clinical trials. However, since evaluations of endoscopic injuries are to some extent subjective (e.g., the endoscopic distinction between an erosion and an ulcer), such injuries must be clearly and correctly defined before the data can be analyzed and considered meaningful. Definitions of injury, endpoints, and protocol design must be consistent with the intent of the study. This becomes evident in drawing distinctions between acute injury, which may resolve, and chronic injury that occurs over a longer period of time. The intent of the study itself should be clearly defined and based on realistic and realizable goals. Only when these criteria are met, and preferably standardized, can clinically relevant studies be performed and compared.