Population-based, 5-year prospective cohort study.
To assess the incidence of musculoskeletal disorders (MSDs) in sickness absence longer than 8 weeks in Norway, and to identify diagnostic and socioeconomic predictors of the transition to disability pension (DP).
MSDs are prevalent and of major concern for sickness absence. Previous epidemiological studies are largely cross-sectional and based on self-reports, often with low response rates, selection, and reporting bias. Prospective studies with physician-verified diagnoses might be a better approach.
Thirty-seven thousand nine hundred forty-two females and 26,307 males with an episode of sickness absence >8 weeks in 1997, certified with a MSD were followed up for 5 years. Diagnostic and sociodemographic data were obtained from a national database. Cases were divided into 9 diagnostic subgroups, based on the International Classification of Primary Health Care. Survival analysis was performed with granting of DP as the endpoint, in the full sample and for diagnostic subgroups.
Over all 20% of cases obtained DP during follow-up. Among those aged 50 to 62 and among those with only basic education 46% obtained DP. DP rates were highest for osteoarthrosis (47%), rheumatoid arthritis (46%), and myalgia/fibromyalgia (38%). Fractures/injuries had the lowest rate. Controlled for age, education and income, relative risk of DP was 1.5 (95% CI: 1.4–1.6) for upper limb problems, 2.0 (95% CI: 1.8–2.1) for back problems, 2.8 (95% CI: 2.5–3.1) for osteoarthrosis, 3.3 (95% CI: 3.0–3.6) for myalgia/fibromyalgia, and 4.2 (95% CI: 3.9–4.7) for rheumatoid arthritis, compared to “fractures and injuries.”
Age, diagnoses, and socioeconomic variables were important predictors of an adverse outcome among workers with a sickness absence of 8 or more weeks. Further research is needed to determine whether differentiated follow-up strategies might prevent permanent disability.
A 5-year follow-up of 37,942 females and 26,307 males with sickness absence >8 weeks, certified with musculoskeletal diagnoses, showed large differences regarding the risk of permanent disability. Age, education, income, and diagnostic subgroups were important predictors of permanent disability.
From the *Section of Social Medicine, Department of Public Health and Primary Health Care, †Program for Health Economics, and ‡Department of Economics, University of Bergen, Norway.
Acknowledgment date: January 31, 2008. First revision date: October 20, 2008. Second revision date: December 31, 2008. Acceptance date: January 5, 2009.
The manuscript submitted does not contain information about medical device(s)/drug(s).
Federal funds from the Norwegian Research Council were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Supported by The Norwegian Research Council with grants to the Health Economy Program, Bergen (to S.G.).
The data were supplied by Statistics Norway but the analyses are the sole responsibility of the authors.
Address correspondence and reprint requests to Sturla Gjesdal, MD, MPH, PhD, Department of Public Health and Primary Health Care, University of Bergen, Kalfarveien 31 Bergen, Norway; E-mail: firstname.lastname@example.org