Effects of internet-based cognitive behavioural therapy and physical exercise on sick leave and employment in primary care patients with depression: two subgroup analyses

Objectives: Depression can negatively impact work capacity, but treatment effects on sick leave and employment are unclear. This study evaluates if internet-based cognitive behavioural therapy (ICBT) or physical exercise (PE), with already reported positive effects on clinical outcome and short-term work ability, has better effects on employment, sick leave and long-term work ability compared with treatment as usual (TAU) for depressed primary care patients (German clinical trials: DRKS00008745).

Methods: After randomisation and exclusion of patients not relevant for work-related analysis, patients were divided into two subgroups: initially unemployed (total n=118) evaluated on employment, and employed (total n=703) evaluated on long-term sick leave. Secondary outcomes were self-rated work ability and average number of sick days per month evaluated for both subgroups. Assessments (self-reports) were made at baseline and follow-up at 3 and 12 months.

Results: For the initially unemployed subgroup, 52.6% were employed after 1 year (response rate 82%). Both PE (risk ratio (RR)=0.44; 95% CI 0.23 to 0.87) and ICBT (RR=0.37; 95% CI 0.16 to 0.84) showed lower rates compared with TAU after 3 months, but no difference was found after 1 year (PE: RR=0.97; 95% CI 0.69 to 1.57; ICBT: RR=1.23; 95% CI 0.72 to 2.13). For those with initial employment, long-term sick leave (response rate 75%) decreased from 7.8% to 6.5%, but neither PE (RR=1.4; 95% CI 0.52 to 3.74) nor ICBT (RR=0.99; 95% CI 0.39 to 2.46) decreased more than TAU, although a temporary positive effect for PE was found. All groups increased self-rated work ability with no differences found.

Conclusions: No long-term effects were found for the initially unemployed on employment status or for the initially employed on sick leave. New types of interventions need to be explored.