Occupational musculoskeletal and mental disorders as the most frequent associations to worker's sickness absence: a 10-year cohort study.

Background: Sickness absence (SA) is a complex phenomenon influenced by the health of the worker and socio-economic factors. An epidemiological study of SA has never been conducted for Brazilian university workers. This study aimed to determine the main diseases that are associated with SA and find out the average length of SA duration, and its variation among different staff members and between sexes over the 10-year study period.

Methods: We identified the main diseases responsible for SA in workers at a Brazilian federal university (UNIFESP) from January 1998 to August 2008 and grouped them according to the International Classification of Diseases (ICD10). Independent researchers assessed data collected from expert reports of the university Worker's Health Division.

Results: During the period of our study, 1176 workers experienced sickness absence. After evaluating 7579 consultations, ICD10 distribution showed that musculoskeletal and connective tissue disorders ("M" axis) and mental and behavioral diseases ("F" axis) were the most important causes of SA, occurring in 47.3% (IC 95%; 44.15-49.8) of workers aged 46.2 (SD 10.1) years. Female workers represented 78.1% (IC 95%; 76-80.7) of all workers with SA, but men had higher proportional rates (Chi-square; p = 0.044). Longer SA periods were observed for illnesses related to neoplasms and infectious diseases.

Conclusions: Musculoskeletal and connective tissue disorders and mental and behavioral diseases were the most frequent cause of sickness absence. Men had an increased frequency of SA, and neoplasms and infectious disorders were associated with longer absences. Mostly, these are occupational disorders. A preventative research-focused agenda is desirable for a more accurate depiction of this population in the scope of policy-making. Our results for SA in Brazilian workers correspond with those of other studies worldwide.