Association between multiple jobs and physical and psychological symptoms among the Korean working population

The prevalence of multiple job-holding (MJH) is expected to show an upward trend among Korean workers, yet its potential impact on workers' health remains poorly discussed. This study aimed to explore the association between MJH and experience of physical and psychological symptoms in various aspects among active Korean workers and to identify its differences depending on workers' gender.

We conducted a population-based cross-sectional study among South Korean workers aged 15-59 using data from the 6th Korean Working Conditions Survey. The final study sample comprised 34,175 participants. MJH status and symptoms, such as musculoskeletal pain, headache or eyestrain, fatigue, insomnia, and anxiety, were measured by self-reported data. Logistic regression analyses were performed on the total sample and gender-stratified groups, with adjustments for the sociodemographic and occupational characteristics of the participants.

One hundred thirty-five men and 103 women were defined as multiple job-holders (MJHers) among the study sample. When adjusted for sociodemographic and occupational characteristics, MJHers suffered more events of headache or eyestrain (odds ratio [OR]: 1.85, 95% confidence interval [CI]: 1.23-2.78) and anxiety (OR: 1.99, 95% CI: 1.05-3.79). Gender-stratified analyses with adjustment showed that among women workers, MJH was associated with musculoskeletal pain (OR: 1.85, 95% CI: 1.02-3.34), headache or eyestrain (OR: 2.53, 95% CI: 1.37-4.67), fatigue (OR: 2.38, 95% CI: 1.29-4.40), insomnia (OR: 1.92, 95% CI: 1.04-3.57), and anxiety (OR: 2.83, 95% CI: 1.11-7.20).

We found a significant association between MJH and various symptoms. Women MJHers were revealed to be a more vulnerable population than their men counterparts. Further research should account for the social context of MJH, and appropriate monitoring and intervention for maintaining the well-being of MJHers are needed.