Cost-effectiveness of a multicomponent intervention against cognitive decline.

Introduction: The societal costs of dementia and cognitive decline are substantial and likely to increase during the next decades due to the increasing number of people in older age groups. The aim of this multicenter cluster-randomized controlled trial was to assess the cost-effectiveness of a multi-domain intervention to prevent cognitive decline in older people who are at risk for dementia.

Methods: We used data from a multi-centric, two-armed, cluster-randomized controlled trial ( trial, ID: DRKS00013555). Eligible participants with increased dementia risk at baseline (Cardiovascular Risk Factors, Aging, and Incidence of Dementia/CAIDE Dementia Risk Score ≥ 9), 60-77 years of age, were recruited by their general practitioners, and assigned randomly to a multi-domain lifestyle intervention or general health advice. We performed a cost-effectiveness analysis from the societal perspective. The time horizon was 2 years. Health care utilization was measured using the "Questionnaire for Health-Related Resource Use in Older Populations." As effect measure, we used quality-adjusted life-years (QALYs) based on the 5-level EQ-5D version (EQ-5D-5L). We calculated the incremental cost-effectiveness ratios (ICER) and cost-effectiveness acceptability curves (CEAC) using the net-benefit approach. Exploratory analyses considering women and the EQ visual analogue scale (EQ VAS) were conducted.

Results: Data were available for 819 participants (mean age 69.0 [standard deviation (SD)5-level EQ-5D version 4.9]); 378 were treated in the intervention group and 441 in the control group. The participants in the intervention group caused higher costs (+€445.88 [SD: €1,244.52]) and gained additional effects (+0.026 QALY [SD: 0.020]) compared to the participants in the control group (the difference was statistically significant). The ICER was €17,149.23/QALY. The CEAC showed that the probability of the intervention being cost-effective was moderate, reaching 59% at a willingness-to-pay (WTP) of €50,000/QALY. The exploratory analyses showed promising results, especially in the female subsample.

Discussion: Considering aspects like the WTP and the limited time horizon, the multi-domain intervention was cost-effective compared to general health advice.

Highlights: The first German randomized controlled trial (RCT) evaluating a multicomponent approach against cognitive decline.We found a favorable incremental cost-effectiveness ratio.The probability of cost-effectiveness reached 78.6%.Women could be an important target group.A longer time horizon is needed.