Assessment of sulfonylurea adherence and metabolic control

This study was designed to compare sulfonylurea adherence assessment by providers, patients' self-report, pill counts, and a medication event monitoring system (MEMS-3) device, and correlate the estimates of metabolic control by provider, patient, and laboratory. Forty-seven outpatient veterans with fair to poor metabolic control of non-insulin-dependent diabetes mellitus were enrolled and received monthly refills of sulfonylurea in vials with a cap containing an electronic medication monitoring microprocessor. Pill counts and fasting plasma glucoses were measured monthly, and glycohemoglobin and a 24-hour diet recall were obtained at 0 and 60 days. Investigators then asked providers and patients to assess adherence and metabolic control. Forty-seven percent were nonadherent to medication using MEMS-3, 29% using pill counts, 29% using provider assessment, and 31% using self-report. Thirty-one percent of providers and 53% of patients assessed metabolic control differently than laboratory values. Assessment of medication adherence by provider, patient, and pill counts did not explain metabolic control as closely as assessment by MEMS-3.