Persistent smoking as a predictor of disability pension due to musculoskeletal diagnoses: A 23Â year prospective study of Finnish twins

- Smoking is a major preventable cause of death associated with many chronic conditions.
- Rare reports exist of smoking and disability pension due to specific diagnosis groups.
- Persistent smoking predicts disability pension due to musculoskeletal diagnoses.
- Smoking and disability pensions are associated independently of many confounders.
- Persistent smoking may have a causal role for permanent work incapacity.

ObjectiveTo investigate whether stability or changes in smoking predict disability pension (DP) due to low back diagnoses (LBD) and musculoskeletal diagnoses (MSD) after taking familial confounding into account using a co-twin design.MethodLongitudinal smoking patterns and multiple covariates in a population-based cohort of 17,451 Finnish twins (6959 complete pairs) born before 1958 were surveyed through questionnaires in 1975 and 1981. The outcome data were collected from the national pension registers until the end of 2004. Cox proportional hazards regression models were used for statistical analyses.ResultsDisability pension due to low back diagnoses was granted to 408 individuals and disability pension due to musculoskeletal diagnoses to 1177 individuals during the follow-up of 23 years. Being a persistent smoker (current smoker both 1975 and 1981) predicted a significantly increased risk for disability pension (hazard ratio 1.69, 95% confidence interval 1.46, 1.97) compared to those individuals who had never smoked. The association remained when several confounding factors, including familial factors, were taken into account.ConclusionPersistent smoking predicts early disability pension due to musculoskeletal diagnoses and low back diagnoses independently from numerous confounding factors, including familial effects shared by the co-twins.