Aim: The attainment of near-normal glycaemia is an important feature in reducing complications in people with type 2 diabetes. Current treatment pathways advocate a failure-driven therapy algorithm for blood-glucose lowering that leads to the sequential addition of therapies. The addition and combination of multiple blood-glucose lowering agents may be associated with significant side effects, such as weight gain and hypoglycaemia, resulting in a detrimental quality of life. The objective of this study is to quantify the overall costs and quality-adjusted life years (QALY) associated with therapy escalation via oral only treatment strategies with different adverse event profiles as a function of target HbA1c achievement.
Methods: A previously published model was adapted to run as a non-terminating simulation model. The model is designed to evaluate the cost utility of treatment strategies in a population of type 2 diabetes mellitus patients. Model outputs include incidence of micro- and macrovascular complications, hypoglycaemia and diabetes-specific and all-cause mortality.
Results: The total number of vascular events predicted by the model varied little across the four treatment strategies because of the glycaemic profile associated with each therapy strategy being similar. The strategy with sequential addition of thiazolidinediones (TZDs) and sulphonylureas (SUs) to metformin (MF) was associated with greatest predicted hypoglycaemia burden. The addition of SU and dipeptidyl peptidase (DPP-4) inhibitors to MF was associated with the highest estimated QALYs.
Conclusions: A treatment strategy involving the sequential addition of SU and TZD to first-line MF therapy is associated with the lowest cost and lowest gain across a population, whereas addition of TZD and SU sequentially to first-line MF therapy resulted in the highest cost and incrementally less QALY gain when compared with treatment strategies involving the addition of a DPP-4 inhibitor and SU to first-line MF (irrespective of the treatment sequence) that were associated with both less cost and greatest QALY gain.