Work Ability Index Predicts Application for Disability Pension After Work-Related Medical Rehabilitation for Chronic Back Pain

ObjectiveTo 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.DesignCohort study with 3-month follow-up.SettingSeven inpatient rehabilitation centers.ParticipantsPatients (N=294; 168 women; mean age, 49.9y) with chronic back pain.InterventionThe 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 MeasureApplication for disability pension, as assessed by a postal questionnaire 3 months after discharge.ResultsReceiver 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.ConclusionsThe WAI could help rehabilitation professionals identify patients with back pain with a high risk of a subsequent application for disability pension.