Inconsistent Use of Diabetes Medications, Diabetes Complications, and Mortality in Older Mexican Americans Over a 7-Year Period

OBJECTIVE: The aim of this study was to examine the relationship between inconsistency in use of diabetes drugs and risk of renal, eye, and circulation problems and death over a 7-year period in community-dwelling older Mexican Americans. RESEARCH DESIGN AND METHODS: Data are from the four waves of the Hispanic Established Population for the Epidemiologic Study of the Elderly. In-home interviewers assessed consistency in use of diabetes medications among 908 diabetic Mexican Americans, aged >or=65 years. Diabetes and complications were by self-report. Subjects with poor consistency in use of medication were those who, at any time during the 7-year follow-up, discontinued or inconsistently used their diabetes medications and those who had no diabetic medications at home despite self-report of taking medicine for diabetes. RESULTS: Thirty-six percent of our sample were inconsistent with diabetes medication usage. Older age and lack of supplemental health insurance were significantly associated with inconsistency of use of medication. In a multivariate logistic regression model, subjects with poor consistency in use of medication were more likely to report kidney problems (odds ratio OR 1.59; 95% CI 1.13-2.23; P = 0.008) at follow-up compared with those with good consistency, after controlling for age, sex, medication type, duration of diabetes, education, income, marital status, language of interview, insurance status, cognitive function, presence of depressive symptoms, activities of daily living, and instrumental activities of daily living. In Cox regression models, poor consistency with diabetic medication was also associated with increased all-cause mortality (hazard ratio HR 1.43; 95% CI 1.13-1.82; P = 0.003) and diabetes-related deaths (1.66; 1.20-2.30; P = 0.002) over a 7-year period after adjusting for relevant confounders. CONCLUSIONS: Inconsistent use of diabetic medication was associated with an increased risk of kidney problems and deaths over a 7-year period in older Mexican Americans.