Early part-time sick leave results in considerable savings in social security costs at national level: an analysis based on a quasi-experiment in Finland

Objectives We analyzed social security costs based on an earlier quasi-experiment that compared work participation between partial sickness beneficiaries and a matched group of full sickness beneficiaries. Methods Utilizing a population-based 70% representative sample, 1878 persons with part-time sick leave (intervention group) due to musculoskeletal diseases or mental disorders at an early stage of work disability and their propensity-score-matched controls with full-time sick leave were followed for two years. The outcome was the difference (absolute and relative) in social security costs between the intervention and control groups during follow-up. Costs of sickness absence, vocational rehabilitation, unemployment, and retirement days were calculated from national administrative registers. Results A cost reduction of €2395 per person per year [95% confidence interval (CI) -2890– -1899) was observed in the intervention compared with the control group. The cost ratio was 0.512 (95% CI 0.511–0.513). The largest savings were attributable to differences in the costs of retirement and vocational rehabilitation. The savings were higher for the second compared with the first follow-up year. Costs were saved across both genders and diagnostic groups, however, savings for women with musculoskeletal diseases were lowest. Conclusions Part-time instead of full-time sick leave, at the early stage of work disability due to musculoskeletal diseases or mental disorders, leads to considerable social security cost savings during two years, in correspondence with increased work participation and in addition to earlier reported health benefits. Part-time sick leave can be recommended from an economic perspective; however more consideration should be given to women with musculoskeletal diseases.