Abstract
Background: While the prevalence of post-disaster musculoskeletal pain has been documented, its associated disaster-related factors have not been investigated. This study determined the prevalence of and lifestyle factors associated with musculoskeletal pain among evacuees of the Great East Japan Earthquake. Methods: We conducted a cross-sectional study of 34,919 evacuees, aged 40-89 years, without obvious disabilities in activities of daily living at about 1 year after the disaster. The evacuees were asked about their musculoskeletal pain (low back and limb pain) and lifestyle factors: use of evacuation shelters or temporary housing at any point of time, job loss after the disaster, decreased income after the disaster, current smoking status, current drinking status, lack of sleep, regular exercise, and participation in recreational or community activities. Furthermore, psychological factors, such as traumatic reactions, psychological distress, and somatic symptoms, affecting musculoskeletal pain were assessed. We used multinomial logistic regression analysis to calculate odds ratios of each lifestyle factor for prevalent and prevalent plus exacerbated musculoskeletal pain. Results: Musculoskeletal pain prevalence was 32.8%: 27.6% for prevalent and 5.2% for prevalent plus exacerbated musculoskeletal pain. Multivariable adjusted odds ratios and 95% confidence intervals of lifestyle factors associated with prevalent and prevalent plus exacerbated musculoskeletal pain were as follows: shelter use (prevalent: 1.02, 0.96-1.08; exacerbated: 1.44, 1.29-1.60), job loss (prevalent: 1.03, 0.96-1.10; exacerbated: 1.30, 1.16-1.47), decreased income (prevalent: 1.13, 1.05-1.21; exacerbated: 1.29, 1.14-1.45), current heavy drinking (prevalent: 1.33, 1.21-1.47; exacerbated: 1.38, 1.14-1.68), insomnia (prevalent: 1.22, 1.15-1.29; exacerbated: 1.50, 1.36-1.65), exercising almost daily (prevalent: 0.83, 0.77-0.91; exacerbated: 0.80, 0.68-0.95), and participating in community activities often (prevalent: 0.83, 0.75-0.92; exacerbated: 0.76, 0.61-0.95). Conclusions: Prevalent and exacerbated musculoskeletal pain were inversely associated with frequencies of exercise and participating in recreational or community activities and positively associated with decreased income, current heavy drinking, and insomnia. The use of evacuation shelters or temporary housing/job loss was positively associated only with exacerbated musculoskeletal pain. These results suggest that post-disaster lifestyle factors are potentially associated with musculoskeletal pain. For better post-disaster pain management, further studies are needed to confirm these results in other disasters and highlight underlying mechanisms.