Two parallel Danish randomised controlled trials known as the IBBIS Trials have found that a programme combining mental health care with vocational rehabilitation for people on sick leave cost more than service as usual, and did not pay for itself through improved productivity or health. The health economic evaluation, published in the journal Cost Effectiveness and Resource Allocation, reports that both variants of the intervention produced negative economic impacts over a 24-month follow-up period.
Common mental disorders of this kind affect approximately 20% of the adult population and have a significant impact on labour market participation and productivity, which is why the economic stakes of return-to-work policy are so high.
At 24 months, the Integrated Intervention showed a net societal cost of €4,645 per participant compared with Service As Usual, while the Mental Health Care arm showed a net societal cost of €7,680. From the government budget perspective, the corresponding net costs were €2,994 for the Integrated Intervention and €5,831 for Mental Health Care. In other words, whichever way the analysis was sliced, both interventions left budgets worse off than standard services.
The primary driver of these negative results was reduced productivity, and the trials found no significant counterbalancing improvements in health-related quality of life.
On the basis of these findings, the authors conclude that the interventions did not achieve cost-effectiveness. They emphasise the need for new treatments that effectively reduce sickness absence and enhance workability after people return to work. According to the discussion, the trials have shown that current interventions are under pressure and fall short of providing the expected economic and health benefits, making it essential to develop innovative strategies that genuinely support individuals’ return to work.
The conclusion drawn by the research team is that the IBBIS Trials highlight the economic challenges of current interventions for common mental disorders and underscore the importance of addressing both health and vocational outcomes if meaningful economic benefits are to be achieved. Developing and testing new approaches that can provide real value and support to those affected remains, in their words, an important unresolved research area.
The study was pre-registered on the Open Science Framework, and the article was published as open access on 28 October 2026 by Andreas Hoff, Rasmus Jacobsen, Serkan Korkmaz and Lene Eplov. For policymakers, the message is sobering: integrating healthcare and employment services, however intuitively appealing, does not automatically deliver savings, and the search for models that do is still open.
Subject of Research: Health economic evaluation of integrated mental health and vocational rehabilitation interventions for people on sick leave with common mental disorders
Article Title: Health economic evaluation of the danish ibbis randomised controlled trials
Article References: Hoff, A., Jacobsen, R., Korkmaz, S., & Eplov, L. (2026). Health economic evaluation of the danish ibbis randomised controlled trials. Cost Effectiveness and Resource Allocation. https://doi.org/10.1186/s12962-026-00851-9
Image Credits: AI Generated
DOI: 10.1186/s12962-026-00851-9
Keywords: IBBIS Trials, common mental disorders, sick leave, return to work, cost-effectiveness, health economics, vocational rehabilitation, randomised controlled trial, Denmark, productivity, mental health care, societal perspective
News Source: Glenn Wilkins. (October 28, 2026). Integrated mental health and return-to-work programme costs more than usual care in Danish trials. Scienmag.
