Does physical or psychosocial workload modify the effect of musculoskeletal pain on sickness absence? A prospective study among the Finnish population.

Abstract

Previously, among food industry workers, multisite pain predicted sickness absence (SA) only in those with low biomechanical workload. Here we studied among a wide range of occupations whether the relationship of pain with SA was modified by the level of physical or psychosocial workload. A nationally representative sample (Health 2000 Survey) comprised 3420 occupationally active Finns aged 30-55years. Baseline data on musculoskeletal pain during the preceding month, strenuous work history, current physical workload, job demands, job control, support at work, lifestyle, and chronic diseases were obtained in 2000/2001 by questionnaire, interview, and clinical examination. Musculoskeletal pain in 18 body locations was combined into four sites (neck, upper limbs, low back, and lower limbs) and classified as no pain, single-site pain, and multisite pain (2-4 sites). The data were linked with information from national registers on annual SA periods lasting ≥10workdays for 2002-2008. Negative binomial regression analysis was used. At baseline, one-third of the study sample reported single-site and one-third multisite pain. Allowing for gender and age, the employees with multisite pain in strata with high physical workload and high job demands tended to have the highest risk of SA, but no statistically significant interactive effects between work factors and pain were observed. Further adjustment for health-related lifestyle and chronic diseases decreased the risk estimates in all strata. We did not find evidence for significant modification by physical or psychosocial workload of the relationship between musculoskeletal pain and SA periods lasting ≥10 workdays.