THE COST-EFFECTIVENESS OF POTENTIAL IMPROVEMENTS IN THE DIAGNOSIS OF AND TREATMENT OF DEPRESSION AMONGST PEOPLE WITH DIABETES

Purpose:    To estimate the cost-effectiveness of potential changes to the care pathway for people with diabetes. The changes considered were improved opportunistic screening for depression, and implementing collaborative care treatment for people with diabetes and depression.

Method(s):    A discrete-event simulation mathematical model was developed of the depression care pathway experienced by people diagnosed with type-2 diabetes in England. Model parameters were based on systematic reviews of the literature. The model was used to assess the costs and health outcomes associated with the potential service changes from an NHS perspective, wider social benefits were also explored. The lifetime outcomes considered were time spent with depression, diabetes-related complications, quality adjusted life years (QALYs), mortality, and healthcare system costs. The changes were considered both separately and in combination, resulting in three potential service changes.

Result(s):    All three changes were associated with reductions in both the time spent with depression and the number of diabetes-related complications experienced. In addition, each of the three policies was associated with an improvement in quality of life and an increase in both life years and depression-free years compared with current practice, but also with an increase in health care costs. Collaborative care dominated improved opportunistic screening, being both cheaper and more effective. The incremental cost-effectiveness ratio (ICER) for collaborative care compared with current care pathways was £10,798 per QALY. Compared to collaborative care, the combined policy of both collaborative care and opportunistic screening had an ICER of £68,017 per QALY.

Conclusion(s):    Service changes to improve the diagnosis of, and treatment of, depression in patients with diabetes may lead to reductions in diabetes related complications and depression, which in turn increases life expectancy and improves health-related quality of life. However, all three service changes lead to an increase in health care costs. Of the changes considered, implementing collaborative care was cost-effective based on current national guidance in England.