Comments on the study 'Renal Effects of Ibuprofen, Piroxicam, and Sulindac in Patients With Asymptomatic Renal Failure,' by Andrew Whetton. Types of patients who are at risk for an acute ischemic insult to the kidney when given nonsteroidal anti-inflammatory drugs (NSAID); Information on the important findings of the study; Description of an ideal characteristic of epidemiologic studies on the effects of NSAID on renal function.