Does the upper-limb work instability scale predict transitions out of work among injured workers?

OBJECTIVE: To investigate the predictive ability of the Upper-Limb Work Instability Scale (UL-WIS) for transitioning out of work among injured workers with chronic, work-related upper extremity disorders (WRUEDs). DESIGN: Secondary analysis of a 12-month cohort study with data collection at baseline and 3-, 6-, and 12-month follow-up. Survey questionnaires were used to collect data on an array of sociodemographic, health-related, and work-related variables. SETTING: Upper extremity specialty clinics. PARTICIPANTS: Injured workers (N=356) with WRUEDs who were working at the time of initial clinic attendance. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Transitioning out of work. RESULTS: Multivariable logistic regression that considered 9 potential confounders revealed baseline UL-WIS (range, 0-17) to be a statistically significant predictor of a subsequent transition out of work (adjusted odds ratio, 1.18; 95% confidence interval [CI], 1.07-1.31; P=.001). An assessment of predictive values across the UL-WIS score range identified cut-scores of <6 (negative predictive value, .81; 95% CI, .62-.94) and >15 (positive predictive value, .80; 95% CI, .52-.96), differentiating the scale into 3 bands representing low, moderate, and high risk of exiting work. CONCLUSIONS: The UL-WIS was shown to be an independent predictor of poor work sustainability among injured workers with chronic WRUEDs; however, when applied as a standalone tool in clinical settings, some limits to its predictive accuracy should also be recognized