Increasing days at work using function-centered rehabilitation in nonacute nonspecific low back pain: a randomized controlled trial.

Objective: To evaluate the effect of function-centered compared with pain-centered inpatient rehabilitation in patients whose absence from work is due to chronic nonspecific low back pain (LBP).

Design: Single-blinded randomized controlled trial with follow-up assessments immediately after treatment and at 3 months.

Setting: Center for work rehabilitation in Switzerland.

Participants: Patients with more than 6 weeks of work absence due to chronic nonspecific LBP (N=174; 137 men, 37 women; mean age +/- standard deviation, 42+/-8 y; mean sick leave before study, 6.5 mo).

Interventions: Function-centered treatment (FCT) (4h/d, 6d/wk, for 3 wk) consisted of work simulation, strength, endurance, and cardiovascular training. Pain-centered treatment (PCT) (2.5h/d, 6d/wk, for 3 wk) used a mini back school, individually selected passive and active mobilization, stretching, and low-intensity strength training.

Main Outcome Measures: The number of days at work in 3 months after treatment, self-efficacy, lifting capacity, pain, mobility, strength, and global perceived effect. Effect sizes (ESs) (Cohen d ) were defined as small (ES range, 0.2-0.5), moderate (ES range, 0.5-0.8), and large (ES, >0.8).

Results: Groups were comparable at baseline. Moderate ESs for the FCT group versus PCT group were found for days at work (25.9 d vs 15.8d, ES=.36, P =.029), self-efficacy (5.9 points vs -7.4 points, ES=.55, P =.003), and lifting capacity (2.3 kg vs 0.2 kg, ES=.54, P =.004).

Conclusions: Function-centered rehabilitation increases the number of work days, self-efficacy, and lifting capacity in patients with nonacute nonspecific LBP.