The relationship between sickness absence periods and work ability index in Korean male automobile parts assembly workers

Introduction
Purpose of this study is to study the relationships between sickness absence and work ability index (WAI) in automobile parts assembly plant.

Methods
A cohort of 299 male subjects working in automobile parts assembly plant was followed prospectively for 3 years. We conducted questionnaire survey for WAI and general characteristics at baseline (2007), and after 3 years. We investigated total periods of sickness absence dates for 3years from 2007 to 2010. Statistical analysis was conducted with X2 test, t-test and logistic regression. SAS (v9.1) was used.

Results
3-Year mean of sickness absence periods were 18.9days. In WAI category the numbers of subjects among poor and moderate ability groups were 88(29.4%) and 154(51.5%) respectively. And the numbers of good and excellent ability group were 53(17.7%) and 4(1.3%) respectively. Smoking group and lower WAI group were related with longer sickness absence. Multiple logistic regression model adjusted by age, BMI and smoking showed that lower WAI score group had higher risk of long term sickness absence (OR=2.6, 95% CI 1.3-5.4).

Discussion
The sickness absence could be related with work ability after adjusting age, smoking, alcohol and disease status. In this study, long term sickness absence is related with work ability. Hence improving work ability could decrease the sickness absence.