Those in lower occupational classes have an increased risk of sickness absence due to musculoskeletal diseases (MSDs), but studies examining the associations simultaneously across specified diagnostic groups within MSDs are lacking. We examined occupational class differences in the occurrence and length of long-term sickness absence due to different musculoskeletal diagnoses.Methods
A 70% random sample of employed Finns aged 25–64 years old at the end of 2013 was linked to data on sickness absence of over 10 working days obtained from The Social Insurance Institution of Finland and occupational class from Statistics Finland. Sickness absences due to MSDs initiated in 2014 were followed until the end of each episode for female (n=675 636) and male (n=604 715) upper non-manuals, lower non-manuals and manual workers. Negative binomial hurdle models were used to analyse the associations.Results
Within the studied MSDs, the most common causes of absence were back disorders, particularly back pain, and shoulder disorders. Osteoarthritis, disc disorders and rheumatoid arthritis induced the longest episodes of absence. Clear hierarchical class differences were found throughout, but the magnitude of the differences varied across the diagnostic causes. The largest class differences in the occurrence were detected in shoulder disorders and back pain. The class differences in length were greatest in rheumatoid arthritis, disc disorders and, among men, also in hip osteoarthritis.Conclusions
Hierarchical occupational class differences were found across different MSDs, with large differences in back and shoulder disorders. Occupational class and diagnosis should be considered when attempting to reduce sickness absence due to MSDs.