The Effects of Stress Perception and Social Indicators on Low Back, Joint, and Shoulder Pains in Japan : Prefecture-Based Analysis of National Surveys in 1995 and 2001

Objectives: Low back, joint and shoulder pains are the three most common complaints among musculoskeletal symptoms in the Japanese people. This study aims to clarify the effects of stress perception and related social indicators on the three musculoskeletal symptoms in a Japanese population. Subjects and method: Twenty health-related variables (stress perception and 19 social indicators) and the three symptoms were obtained from the following Japanese national surveys: the Comprehensive Survey of Living Condition of the People on Health and Welfare, the System of Social and Demographic Statistics of Japan, and the Statistical Report on Health Administration Services. Concerning the definition of stress perception, the subjects answered "yes" if they perceived any of the stressors for the following 27 life-related categories including work, family, neighbourhood relations, as well as living-, social-, financial-, and health related situations. Among 46 Japanese prefectures, exclusive of Hyogo Prefecture, multiple regression analyses (stepwise method) were used to assess the effects of the stress perception on the prevalence of the musculoskeletal symptoms, taking the significant effects of the social indicators into consideration in 1995 and 2000. Results: By factor analysis, the 19 indicators were classified into three factors of urbanization, aging and life-regularity, and individualization. The prevalence of stress perception was significantly correlated to the 8 indicators of urbanization factor. Simple correlation analysis revealed a significant relationship of stress perception only to low back pain (in 2001) and shoulder pain (in both years). The results of multiple regression analysis showed that stress perception was related to low back and shoulder pain in 1995, after controlling for the effects of the other indicators of the urbanization factor (e.g. lower proportion of farming and higher education for shoulder pain) and those of the aging factor (e.g. natural population growth and female gender for low back pain). In 2001 stress perception was related to all three musculoskeletal symptoms through the same regression analyses. Conclusion: Taking the effects of urbanization into consideration, stress perception seems to be closely related to the complaints of musculoskeletal symptoms in Japan. Although the present findings were obtained from prefecture-based dataset, they have some important practical implications. Health staff should be aware of the close association between stress and musculoskeletal symptoms. Within the context of a thorough evaluation of stress and social life factors, the reporting of symptoms may be an important signal to consider for referring patients to the specialists for exclusion of psychiatric conditions or for stress management. In addition to such individual approaches, we may consider population approaches to tackle stress where many people complain of these musculoskeletal symptoms.