Study of chronic pain and its associated risk factors among Japanese industry workers: the Quality of Working Life Influenced by Chronic pain (QWLIC) study

OBJECTIVES: This study was performed to identify the prevalence, influence, and risk factors associated with chronic pain among Japanese industry workers.

METHODS: We investigated 2,544 participants working at a manufacturing company A, a manufacturing company B, and 16 branch shops of a retail chain company C. The participants responded to self-administered questionnaires related to pain. Furthermore, data obtained from the lifestyle interview sheet of an annual health screening examination and those obtained from the questionnaires were merged. We analyzed the association between lifestyles, psychosocial factors, and chronic pain. Age- and sex-adjusted odds ratios were calculated with a 95% confidence interval using the logistic regression model.

RESULTS: Of 2,544 participants, 1,914 (1,224 men and 690 women) completed the questionnaire, and the response rate was 75.2%. The prevalence of chronic pain over 3 months was 42.7% and that of chronic pain with work disability was 11.3%. A higher proportion of obesity, smoking habit, insomnia, psychological stress, depressive state, workaholic nature, low social support from supervisors and coworkers, high job demand, low job control, and job dissatisfaction was observed in workers with chronic pain than in workers without pain.

CONCLUSIONS: Several risk factors of chronic pain in Japanese industry workers were found. Obesity, smoking habits, sleep disorders, workplace environment, and mental state should be taken into account as risk factors associated with chronic pain issues and general occupational health.