Trends in selection and timing of first-line pharmacotherapy in older patients with type 2 diabetes diagnosed between 1994 and 2006.

AIMS To characterize temporal trends in the selection and timing of first-line pharmacotherapy among older patients with Type 2 diabetes. DESIGN AND METHODS We studied five population-based cohorts every 3 years, from 1994 to 2006. In each of those years, we identified all subjects aged 66 years or older newly diagnosed with diabetes and determined the initial glucose-lowering drug and the time between diagnosis and drug initiation. We calculated the proportion of patients prescribed each agent and estimated time from diagnosis to initiation using Kaplan-Meier survival analysis. RESULTS We identified a total of 64 368 eligible people who initiated drug therapy during the study period. From 1994 to 2006, first-line metformin use increased from 20.1 to 79.0%. Glyburide (glibenclamide) decreased from 71.1% of all first-line therapies in 1994 to 9.8% in 2006, while first-line use of insulin or combination therapy have changed little at approximately 5% each. No other medication exceeded 2% of first-line therapies. The median time from diagnosis to initiation of pharmacotherapy increased dramatically during the study period, from 1.8 years in 1994 to 4.6 years in 2006. CONCLUSIONS Metformin has become the most commonly used initial medication for the treatment of diabetes. Although guidelines have evolved to recommend more aggressive initiation and intensification of pharmacotherapy, our results suggest that the time from diagnosis to initiation has increased substantially.