Background: Manual work is reported to be a risk factor for becoming a disability pensioner due to osteoarthritis. This association may be due to covariation with other variables. We wanted to assess if manual work remained a risk factor after adjusting for number of hours worked, income, level of education, gender and marital status, and if the risk associated with manual work was equal in the 1970s and the 1980s.
Methods: In a prospective study, data on all new disability pensioners with osteoarthritis in Norway during the two follow-up periods, 1971-1980 and 1981-1990, were analysed by logistic regression. The study include data on all subjects living in Norway and registered as 50-56 years old and employed either in the census collected in 1970 or in the census of 1980.
Results: Manual workers have nearly twice the probability of becoming a disability pensioner with osteoarthritis compared to professionals after adjusting for part-time work, income, level of education, marital status and gender. Adjusted for other risk factors, the probability of becoming a disability pensioner with osteoarthritis was three times higher in the 1980s compared to the 1970s.
Conclusion: The relatively strong association between manual work and disability pensioning with osteoarthritis suggests difficulties in adjusting manual work patterns for a person with osteoarthritis, which may have increased during the study period as implied by the separate effect of the 1980s.