Reducing loneliness to prevent depression in older adults in Australia: A modelled cost-effectiveness analysis

Abstract Purpose : The aim of the study was to evaluate the cost-effectiveness of the Friendship Enrichment Programme (FEP) and a volunteer-led internet and computer training (VICT) intervention to reduce loneliness in older adults and, in turn, prevent depression. Method : A population-based Markov model was developed to estimate the cost per quality-adjusted life year (QALY) gained and the return on investment (ROI) generated by investing in the interventions from a partial societal perspective. The model consisted of three health states (lonely, not lonely and dead). Costs, QALYs, and the subsequent impacts on depression associated with different health states were modelled. Both interventions were compared to a ‘no intervention’ scenario over a 5-year time horizon. Probabilitistic and deterministic sensitivity analyses were undertaken for both interventions. Results : The incremental cost-effectiveness ratio was dominant across both interventions, indicating that they were less costly and more effective when compared to the comparator. Results remained robust in the deterministic sensitivity analyses. However, probabilistic sensitivity analyses indicated high uncertainty, with only 55% and 68% of uncertainty iterations lying below the A$50,000 per QALY gained willingness-to-pay threshold for FEP and VICT, respectively. Both interventions generated cost savings that were greater than intervention costs, with a ROI of 2.87 for the FEP and 2.14 for the VICT intervention after 5 years. Conclusion : While FEP and VICT were found to be cost saving with positive returns on investment, the current evidence on intervention effectiveness is limited and needs to be strengthened before routine rollout can be recommended.