Background: Multi-site pain is a common phenomenon among working-age people and it strongly increases work disability risk. Little is known about the impact of musculoskeletal pain on work ability.
Aims: To investigate whether the number of musculoskeletal pain sites predicts future poor work ability.
Methods: The study was conducted in 2005 and 2009 in a food processing company. A total of 734 workers participated in the study. The information on self-perceived work ability and musculoskeletal pain during the preceding week was obtained through a structured questionnaire distributed to employees. The risk of poor work ability at follow-up related to the number of pain sites at baseline was estimated with logistic regression.
Results: The proportion of poor work ability increased in 4 years from 15 to 22%, parallel to the increase in the number of pain sites. Among those with 'non-poor' work ability at baseline, one-tenth reported their work ability to be poor after 4 years. The number of pain sites predicted poor work ability after 4 years of follow-up with a dose-response manner. Those with widespread pain had almost a 3-fold risk of developing poor work ability at follow-up. The associations were stronger for younger and white-collar workers.
Conclusions: The results of the present study indicate that multi-site musculoskeletal pain at baseline strongly predicts poor work ability after 4 years among industrial workers. Counting the number of concurrent pain sites may be a simple method of identifying workers with high risk of work disability in occupational health practice.