Patients with a future diagnosis of diabetes have higher drug use and costs: an analysis of community pharmacy data

This study explores whether patients with Type 2 diabetes mellitus have higher drug use as compared to patients without diabetes over a time period prior to and after diagnosis of diabetes. A case-control study compared drug use of patients with a future diagnosis of diabetes (cases) with patients without a diagnosis (controls) based on community pharmacy records. Cases had used oral hypoglycaemic drugs during 2006. A repeated measures analysis calculated the mean number of packages and costs of drugs in cases during the two years prior to diagnosis and the first year following diagnosis and in control patients during three years. Volume of drug use was expressed as the number of packages consumed by a patient. Drug costs were based on the public price. Our dataset covered 2,697 patients (899 cases and 1,798 control patients). The mean annual number of packages and costs of drugs increased over time for cases and control patients (p<0.001). In patients with a future diagnosis of diabetes, the growth in drug use and costs over time was more pronounced than in control patients (p<0.001). Higher drug use and costs were mainly observed for cardiovascular drugs, antidepressant and antipsychotic drugs, and drugs related to gastric acid disorders. Patients with a future diagnosis of diabetes have higher drug use and costs prior to diagnosis than control patients. Drug use could be an indicator to trigger active monitoring for Type 2 diabetes mellitus.