JMIR Publications

ABSTRACT

Background:

Despite Korea’s high self-employment rate, few studies have examined the health of self-employed workers in Korea.

Objective:

To compare the risk of mortality and other comorbidities between self-employed and employee populations in Korea.

Methods:

This nationwide retrospective study used data from the Korean National Health Insurance Service Database. Participants aged 20–59 years who maintained the same insurance type of self-employed or employee for three years or more (at least 2009–2011) were recruited for this study and monitored until death or December 2021, whichever occurred first. All-cause mortality was the primary outcome. Cumulative incidences were estimated using the Kaplan–Meier method. A multivariable Cox proportional hazard model was used to estimate the adjusted hazard ratio and 95% confidence intervals for each sex strata. Subgroup analyses were also performed.

Results:

Among 11,652,716 participants (median follow-up: 10.92-year; median age: 42; male proportion: 68.44%), all-cause mortality occurred in 99,542 (1.27%) employees and 124,963 (3.29%) self-employed individuals (p<0.001). The 10-year cumulative incidences of all-cause mortality by employment status differed significantly: 1.1% for employees and 2.8% for self-employed individuals (p<0.001). The risk of all-cause mortality among self-employed individuals compared to employees was significantly higher, particularly among women, according to the final model (adjusted hazard ratio [95% confidence interval]: 1.437 [1.422–1.452] for men and 1.888 [1.841–1.936] for women). According to subgroup analyses, this association was prominent in younger individuals with a lower income who formed a part of non-participation groups.

Conclusions:

This study found a significantly increased risk of all-cause mortality and cardiovascular diseases among self-employed individuals compared to employees.