The relations between work demands and health complaints in lorry drivers. A model tested by means of LISREL

In this study, data of a questionnaire study among 439 lorry drivers were fitted to a model in which work demands and the worker's decision latitude are related to musculoskeletal complaints and general psychosomatic complaints. Structural analysis with LISREL was used to investigate the hypothesized relations. Two modifications resulted in a chi 2 of overall fit equal to 77.35 with 47 degrees of freedom. The quality of model fit was considered to be satisfactory when the sample size was taken into account. The values of the Adjusted Goodness of Fit Index (0.948) and the Root Mean Square Residuals (0.029) indicated the same. The standardized solution of LISREL showed that work demands with respect to task contents were significantly related to musculoskeletal complaints as well as to general psychosomatic complaints (0.75 and 0.34 respectively, both P < 0.001). This conceptual variable was indicated by physical activities that the drivers had to perform. The relations between work-related psychosocial factors and musculoskeletal complaints were weak. Another significant effect on general psychosomatic complaints was found for work demands with respect to terms of employment (0.30, P < 0.001). This conceptual variable was indicated by variables concerning working hours and pressure of the work. It is recommended that in future occupational epidemiology, both physical and psychosocial aspects of the working situation be related to health effects, rather than solely a single exposure variable.