Treatment intensification in patients with type 2 diabetes who failed metformin monotherapy

Abstract

To evaluate the time to and factors associated with treatment intensification in patients with type 2 diabetes who failed metformin monotherapy. In a retrospective analysis using a large US electronic medical record database, eligible patients included those with type 2 diabetes and an HbA(1c) of ≥7.0% or at least two fasting blood glucose levels of ≥126 mg/dl while on metformin monotherapy for at least 6 months within the period of 1 January 1997 to 31 December 2008. Time to treatment intensification was calculated as the time between index date (date on which HbA(1c) ≥ 7% after metformin monotherapy for at least 6 months) and first prescription for additional antihyperglycaemic agent during follow-up period. All patients were required to have data for at least 12 months prior to and following the index date. A Cox proportional hazards model was employed to determine patient baseline characteristics associated with time to treatment intensification. Of the 12 566 patients identified, mean age at index date was 63 years and 51% were female. Mean index HbA(1c) was 8.0% overall, with 66, 19 and 15% of patients having an index HbA(1c) of 7 to <8%, 8 to <9% and ≥9%, respectively. Median time to treatment intensification was 14.0 months overall and 19.0, 8.7 and 4.5 months for patients with index HbA(1c) of 7 to <8%, 8 to <9% and ≥9%, respectively. Factors associated with treatment intensification included higher index HbA(1c) , younger age, higher Charlson co-morbidity index, metformin daily dose ≥ 1500 mg and later index date (all p < 0.05). In US clinical practice, median time to receive additional antihyperglycaemic medication is more than 1 year for patients with type 2 diabetes who failed metformin monotherapy.