Objectives: Schizophrenia has been found to be associated with poor medication adherence, and a higher prevalence of diabetes. As appropriate adherence to hypoglycemic therapy is crucial for good glycemic control, this study aimed to compare medication adherence to oral hypoglycemic therapy, as well as diabetic care and risk of acute complications between type II diabetics with schizophrenia versus those without schizophrenia. Methods: This study used the National Health Insurance claims data of a randomly selected sample. Enrollees who had received oral hypoglycemic therapy in 2002 and had been diagnosed with schizophrenia were included in the study (the case group). Enrollees without schizophrenia who had received oral hypoglycemic therapy in 2002 were selected to match the age and gender of the case group (1:3) (the comparison group). All subjects were observed for one year after their index dates – the dates of their first filled prescriptions in 2002. Medication possession ratio (MPR) was measured as MPR<0.8 indicated poor adherence. Indicators of diabetic care included blood glucose test and HbA1c test. Acute complications were defined as emergency room visits or hospital admissions due to coma, hypoglycemia, hyperglycemia, or diabetic ketoacidosis. Logistic models were used to evaluate likelihood of poor medication adherence and access to diabetic care. Cox proportional hazards model was adopted to assess risk of acute complications. Results: There were 202 and 606 subjects in the case group and comparison group, respectively. The mean age was 52, and 48% were male. Approximately half of both groups were poorly adherent to their oral hypoglycemic therapy. Diabetics with schizophrenia were less likely to receive HbA1c test. Their risks of acute complications were comparable. Conclusions: According to our preliminary results, diabetics with schizophrenia, compared with those without such a condition, had worse diabetic care. Better disease management will be necessary for this patient group.
