Delaying Second Line Diabetes Treatment Onset In Patients Uncontrolled With Metformin Xr In Saudi Arabia: Cost-Effectiveness Analysis

Type 2 diabetes mellitus (T2DM) treatment guidelines recommend therapy intensification with a second oral agent if glycated hemoglobin (HbA1c) target is not achieved over three to six months. However, in clinical practice, therapy intensification occurs as soon as one month. The objective of this study was to compare the cost-effectiveness of treatment intensification with metformin/ DPP4i inhibitor fixed-dose combination in uncontrolled patients (HbA1c > 7.5%) at three versus one month(s) after metformin XR monotherapy initiation. A discrete event simulation model was created based on UKPDS and a comprehensive literature review was performed in order to model lifetime therapeutic sequence in T2DM. This model was adapted to include a monthly HbA1c profile progression, an adherence impact on effectiveness and to consider Saudi Arabian specific data. This model allowed the lifetime assessment of quality adjusted life years (QALY), persistence in metformin, time to insulin therapy, percentage of patients with diabetes complications and costs. Postponing therapy intensification will lead to more patients achieving HbA1c target, augmenting metformin monotherapy (3 months group: 3.58 years vs 1 month group: 3.28 years) and delaying insulin therapy initiation by 6.8 months (3 months group: 12.31 years vs 1 month group: 11.75 years). As a consequence, cost savings of 7,591 SAR (3 months group: 420,356 SAR vs 1 month group: 427,948 SAR) and QALY gains (3 months group: 12.46 QALY vs 1 month group: 12.39 QALY) are estimated. The percentage of patients with long-term diabetes complications as congestive heart failure decreases with postponing therapy intensification (3 months group: 12.02% vs 1 month group: 12.17%), as well as diabetes complications costs (3 months group: 185,936 SAR vs 1 month group: 186,310 SAR). Saudi Arabian guidelines recommendation is not only cost saving but also increases metformin persistence and time to insulin therapy initiation.