University Group Diabetes Program. A multicentered clinical trial completed in the 1960s assessed the efficacy of various oral hypoglycemics, insulin, and diet in preventing vascular complications of diabetes.cc It found that 26 of 204 patients (13%) treated with the oral hypoglycemic phenformin died unexpectedly from cardiovascular events. In contrast, 2 of 64 control patients (3%) experienced a similar outcome.

a.Test the difference for significance.