Scand J Work Environ Health 2014;40(4):428-431 pdf full text
https://doi.org/10.5271/sjweh.3428 | Published online: 03 Apr 2014, Issue date: 01 Jul 2014
Work ability as prognostic risk marker of disability pension: single-item work ability score versus multi-item work ability index
Objectives Work ability predicts future disability pension (DP). A single-item work ability score (WAS) is emerging as a measure for work ability. This study compared single-item WAS with the multi-item work ability index (WAI) in its ability to identify workers at risk of DP.
Methods This prospective cohort study comprised 11 537 male construction workers, who completed the WAI at baseline and reported DP after a mean 2.3 years of follow-up. WAS and WAI were calibrated for DP risk predictions with the Hosmer-Lemeshow (H-L) test and their ability to discriminate between high- and low-risk construction workers was investigated with the area under the receiver operating characteristic curve (AUC).
Results At follow-up, 336 (3%) construction workers reported DP. Both WAS [odds ratio (OR) 0.72, 95% confidence interval (95% CI) 0.66–0.78] and WAI (OR 0.57, 95% CI 0.52–0.63) scores were associated with DP at follow-up. The WAS showed miscalibration (H-L model χ²=10.60; df=3; P=0.01) and poorly discriminated between high- and low-risk construction workers (AUC 0.67, 95% CI 0.64–0.70). In contrast, calibration (H-L model χ²=8.20; df=8; P=0.41) and discrimination (AUC 0.78, 95% CI 0.75–0.80) were both adequate for the WAI.
Conclusion Although associated with the risk of future DP, the single-item WAS poorly identified male construction workers at risk of DP. We recommend using the multi-item WAI to screen for risk of DP in occupational health practice.
Key terms construction worker; disability pension; discriminative ability; prognostic research; prognostic risk marker; risk marker; ROC curve; sensitivity; single-item workability score; specificity; WAI; WAS; work ability; work ability index