Impact of asthma or respiratory symptoms on work-functioning impairment among Japanese workers: The Japanese Red Cross Kumamoto Study

This study evaluated work-functioning impairment (presenteeism) among Japanese workers with asthma or respiratory symptoms. This cross-sectional study included 3038 workers who completed respiratory function tests, a routine interview questionnaire regarding disease history and symptoms, and an additional questionnaire, the Work-Functioning Impairment Scale (WFun), during health checkups. Workers were divided by presence of asthma, respiratory symptoms, or treatment. According to the WFun score, outcomes were classified into two groups: no work-functioning impairment (a score of ≦20) and work-functioning impairment (a score of ≧21). Logistic regression analysis was used to assess these associations. Compared to “workers without asthma or respiratory symptoms” (reference group), “workers with both asthma and respiratory symptoms” had significant work-functioning impairment (odds ratio [OR] = 3.91, 95% CI: 1.92–7.97) and use of sick leave after adjustment. “Workers with asthma but without respiratory symptoms” did not show a significant work-functioning impairment (OR = 1.39, 95% CI: 0.87–2.21). Within the asthma group, work-functioning impairment was significantly associated with “workers with both asthma and respiratory symptoms” compared to “workers with asthma but without respiratory symptoms” after adjustment (OR = 6.53, 95% CI: 2.12-20.14). Asthma and respiratory symptoms were significantly associated with sick leave use. However, for work-functioning impairment, the presence of respiratory symptoms was significantly associated, whereas with asthma but without respiratory symptoms was not. Thus, our findings indicate that asthma alone does not lead to work-functioning impairment. Our findings suggest that therapeutic interventions should be strengthened.