Sickness absence indicating depressive symptoms of working population in South Korea

Sickness absence has been regarded as an important indicator of workers' health and work productivity. This study is aimed to evaluate the association between depressive symptoms and sickness absence in workers of South Korea.

We used nationwide cross-sectional survey data from 2889 individuals in the working population aged over 19 years in South Korea. Depressive symptoms were measured using Patient Health Questionnaire-9 (PHQ-9). Those respondents who scored above 10 on PHQ-9 were regarded as having depressive symptoms. Sickness absence was considered a binary variable with an absence of at least 1 day in the past month. The survey instrument contained questions about sociodemographic factors, lifestyle, work-related factors, and chronic illnesses. Logistic regression models were used to find odds ratios and confidence intervals.

The prevalence of sickness absence was found to be overall 4.6%. The adjusted odds ratio of sickness absence with depressive symptoms (PHQ-9 score ≥ 10) was 3.63 (Confidence Interval: 2.13-6.20) after controlling of possible confounders. Compared to minimal depressive symptoms (PHQ-9 < 5), the differences between other types of severity of depressive symptoms (mild, moderate, and moderately severe) in terms of mean of all sickness absences were more significant.

The sickness absence based on the memory of the respondent in this study may result in a recall bias.

Incidence of at least 1 day of sickness absence per month increased the risk of depressive symptoms after controlling for the possible confounding factors in general working population. It may be necessary to consider strategies for assessing depression in the workers who take sick leaves.