Work ability index predicts application for disability pension after work-related medical rehabilitation for chronic back pain

Objective: To determine whether the Work Ability Index (WAI), a short 7-item self-report questionnaire addressing issues of perceived disability, impairment, and expectations for resuming work, predicts application for disability pension, recommendations for further treatment, and other adverse work-related criteria in patients with chronic back pain after rehabilitation. Design: Cohort study with 3-month follow-up. Setting: Seven inpatient rehabilitation centers. Participants: Patients (N=294; 168 women; mean age, 49.9y) with chronic back pain. Intervention: The WAI was completed at the beginning of rehabilitation. All patients were treated according to the German rehabilitation guidelines for chronic back pain and work-related medical rehabilitation. Main Outcome Measure: Application for disability pension, as assessed by a postal questionnaire 3 months after discharge. Results: Receiver operating characteristic curve analysis of the association between the WAI at baseline and subsequent application for disability pension revealed an area under the curve of.80 (95% confidence interval [CI],.62-.97). Youden index was highest when the WAI cutoff value was ≤20 points (sensitivity, 72.7%; specificity, 82.2%; total correct classification, 81.7%). After adjusting for age and sex, persons with a baseline WAI score of ≤20 points had 15.6 times (95% CI, 3.6-68.2) higher odds of subsequent application for disability pension, 4.9 times (95% CI, 1.5-16.8) higher odds of unemployment, and 6 times (95% CI, 2.4-15.2) higher odds of long-term sick leave at follow-up. Conclusions: The WAI could help rehabilitation professionals identify patients with back pain with a high risk of a subsequent application for disability pension.