# Effectiveness of two vocational interventions on sickness absence and costs for people with musculoskeletal disorders: 12 months results from the MI-NAV multi-arm randomized trial

## TL;DR

This study found that adding motivational interviewing or vocational advice to usual care helps people with musculoskeletal disorders return to work faster and is cost-effective.

## Contribution

The study demonstrates that adding MI or SVAI to usual care reduces sick leave and is cost-effective for people with musculoskeletal disorders.

## Key findings

- UC+MI and UC+SVAI reduced sick leave days by 15.6 and 17.6 days respectively compared to UC.
- Both interventions were associated with lower odds of receiving wage replacement benefits.
- SVAI showed a higher net benefit (€7214) compared to MI (€5225) per person.

## Abstract

This study aimed to assess 12-month outcomes on return to work (RTW) and cost-effectiveness in adults on sick leave due to musculoskeletal disorders who were randomized to either usual case management (UC), UC+motivational interviewing (MI) or UC+stratified vocational advice intervention (SVAI).

The study was conducted in the Norwegian Labor and Welfare Administration (NAV). Workers on sick leave due to musculoskeletal disorders for ≥50% of their contracted work hours for ≥7 consecutive weeks were included. Trained case workers delivered MI in two face-to-face sessions, and physiotherapists provided SVAI and identified RTW obstacles. The main outcomes were sick leave days over 12 months and cost-effectiveness, cost-utility and cost-benefit.

The trial included 509 workers with a mean age of 48 years. There were statistically significant differences between UC+MI versus UC [-15.6 days, 95% confidence interval (CI) -31.0– -0.2], and UC+SVAI versus UC (-17.6 days, 95% CI -33.0– -2.2). Compared to UC, odds ratios (OR) for receiving wage replacement benefits each month were lower for UC+MI (OR=0.73, 95% CI 0.64–0.84), and UC+SVAI (OR 0.74, 95% CI 0.64–0.84). The probabilities of cost-effectiveness were high for adding either MI or SVAI to UC (ceiling ratio 0.90), and the net benefit for MI was €5225 (95% CI -592–10 985) and for SVAI €7214 ((95% CI 1548–12 851) per person.

Adding MI or SVAI to UC significantly improved RTW outcomes and was cost-effective among people on sickness absence due to musculoskeletal disorders.