VA cooperative study on antiplatelet agents in diabetic patients after amputation for gangrene. IV. Issues in design, interpretation, and analysis.

This paper review some of the issues faced by the investigators involved in a VA Cooperative Study on Antiplatelet Agents in Diabetic Patients after Amputation for Gangrene. The study was a negative one, and some of the reasons for this are considered. In addition, suggestive results in two subgroups, cerebrovascular disease and unexpected, sudden, or unobserved deaths, were found. The implications and interpretation of these findings are discussed.