Diagnostic Accuracy of the Work Functioning Impairment Scale (WFun): A Method to Detect Workers Who Have Health Problems Affecting their Work and to Evaluate Fitness for Work.

Objective: This study evaluated the diagnostic accuracy of the Work Functioning Impairment Scale (WFun), a questionnaire to detect workers with health problems which affect their work, using an assessment by an occupational health nurse as objective standard.

Methods: The WFun was completed by 294 employees. The nurse interviewed to assess 1) health problems; 2) effects of health on their work; necessity for 3) treatment, 4) health care instruction, and 5) consideration of job accommodation.

Results: The odds ratio in the high work functioning impairment group compared with the low was highly statistically significant with 9.05, 10.26, 5.77, 9.37, and 14.70, respectively. The WFun demonstrated the high detectability with an area under the receiver operating characteristic of 0.75, 0.81, 0.72, 0.79, and 0.83, respectively.

Conclusions: This study suggests that the WFun is useful in detecting those who have health problems affecting their work.