The objectives of this project were to: (1) examine the associations among stressful exposures in the job and home environments and musculoskeletal disorders (MSD) symptoms; (2) test some of the possible pathways that may link stress from these environments to the development of MSD symptoms; and (3) explore potential demographic (race and age) and mediating factors (psychosomatic symptoms, depression, and anxiety) that may work directly or indirectly with stress to cause or exacerbate MSD symptoms. Data from a cross-sectional survey of women working in customer service within the telecommunications industry were used. The majority of the women in the sample were married (n=122, 56%), with some college or post-high school training (n=97, 44%). Most were parents (n=166, 77%), with, on average, 2 children. The mean age was approximately 42 years. The sample was made up equally of people identifying themselves as either African-American or white (n=108, 50%; n=102, 47% respectively). The average tenure on the job was 215.8 months (approximately 18 years). Symptoms from five musculoskeletal systems were analyzed: hands, neck, shoulders, upper back and lower back. From the reported symptoms, cases and non-cases were defined and used in subsequent analyses. Stress from home and the job was conceptualized using the Job Strain Model (Demand/Control model). Both standardized measures and newly developed, job specific measures were used. Standardized measures were also used to measure psychological morbidity. These data showed that demands from the job was the most important factor related to MSD symptoms. Those with high physical demands appeared to have the highest odds of having MSD symptoms. Demands, control, and social support at home were not directly related to MSD symptoms, nor did they modify the relationship between their parallel measures in the job environment and symptoms. Psychological morbidity was also related to MSD symptoms. Elevated state anxiety was directly related to symptoms, while depression and psychosomatic symptoms acted as mediators between job and home demands and MSD symptoms, especially symptoms in the lower back. Psychological ill health also acted as a modifier: low job support and depression, together, increased the odds of having neck or upper back symptoms, just as high job demands coupled with either high levels of depression or trait anxiety increased the odds of having low back symptoms. The effects of race and age on stress from the home and job environment and on MSD symptoms were inconsistent and inconclusive. Differences by race were found in the home environment, but these differences were not maintained when variables from the job environment were taken into consideration. The effects of age were minimal, possibly indicating the 'healthy worker effect' for this population. In sum, for this study job demands was the most important factor linking job and home strain to MSD symptoms. An additional finding of equal interest, however, was the effect and influence of psychological ill health on job and home strain and, in turn, on some MSD systems, but not others.
University College London, International Centre for Health and Society, Department of Epidemiology and Public Health, 1-19 Torrington Place, 4th Floor, London England WC1E 6BT