Sick Leave

The objective of this study is to evaluate the effect of an intervention, SmaRTWork, on return to work compared to usual care for individuals who are sick-listed due to musculoskeletal disorders. Potential participants are individuals of working age (20-59 years) sick-listed due to a musculoskeletal disorder (neck pain, low back pain, or widespread pain) for up to 12 weeks living in Norway. The primary outcome will be time to sustainable return to work. We will also evaluate the effect on other work outcomes and health outcomes. We will also interview participants and stakeholders about their experience with the intervention.

This prospective multicenter cohort study evaluates the predictive value of the Adaptive Load Index (ICA), a composite indicator derived from the WB6Dim well-being instrument, on long-duration sick leave (≥ 30 days) in French companies at a 6-month horizon. In France, 7% of sick leave episodes (those exceeding 6 months) account for 45% of total sickness benefit expenditure (Cour des Comptes 2024). Group disability insurance charges rose +24.4% in 2024 (France Assureurs 2025). Critically, a substantial proportion of long-duration sick leave occurs without prior escalation in administrative absence data - the 'cliff effect' - where presenteeism masks progressive deterioration (Gustafsson \& Marklund 2011). Prediction models based solely on absence history plateau at AUC 0.65 for cumulative days (Roelen 2013), while composite psychometric instruments reach C-index 0.73-0.74 (Airaksinen et al. 2018, SJWEH). The WB6Dim is a validated 28-item psychometric tool measuring 9 dimensions of workplace well-being (NCT07301879, NCT07433764; test-retest ICA .904). The ICA classifies respondents into 4 adaptive load levels. Aggregated at the company level, the ICA distribution may detect deterioration during the presenteeism window, before costly sick leave materializes. The study collects 4 WB6Dim assessments over 6 months alongside company-level absence data stratified by duration (2024-2026) and individual self-reported absence data (duration and episode count). Six pre-registered hypotheses test whether ICA predicts long-duration leave, including an exploratory hypothesis targeting companies with no prior absence signal but degraded well-being scores.

The objective of this study is to evaluate the effect of an intervention, SmaRTWork, on return to work compared to usual care for individuals who are sick-listed due to musculoskeletal disorders. Potential participants are individuals of working age (20-59 years) sick-listed due to a musculoskeletal disorder (neck pain, low back pain, or widespread pain) for up to 12 weeks living in Norway. The primary outcome will be time to sustainable return to work. We will also evaluate the effect on other work outcomes and health outcomes. We will also interview participants and stakeholders about their experience with the intervention.