Hypothyroidism is a predictor of disability pension and loss of labor market income: a Danish register-based study.

Abstract

Hypothyroidism is associated with an increased somatic and psychiatric disease burden. Whether there are any socioeconomic consequences of hypothyroidism, such as early retirement or loss of income, remains unclarified. Our aim was to examine, compared with a matched control group, the risk of receiving disability pension (before the age of 60) and the effect on labor market income in patients diagnosed with hypothyroidism. This was an observational register-based cohort study. By record linkage between different Danish health registers, 1745 hypothyroid singletons diagnosed before the age of 60 were each matched with 4 non-hypothyroid controls and followed for a mean of 5 (range 1-31) years. Additionally, we included 277 same-sex twin pairs discordant for hypothyroidism. The risk of disability pension was evaluated by the Cox regression analysis. Changes in labor market income progression over 5 years were evaluated using a difference in difference model. With a hazard ratio of 2.24 (95% confidence interval = 1.73-2.89), individuals diagnosed with hypothyroidism had a significantly increased risk of disability pension. This remained significant when adjusting for educational level and comorbidity (hazard ratio = 1.89; 95% confidence interval = 1.42-2.51). In an analysis of labor market income, 2 years before compared with 2 years after the diagnosis of hypothyroidism, the hypothyroid individuals had on average a €1605 poorer increase than their euthyroid controls (P < .001). Essentially similar results were found in the twin population. A diagnosis of hypothyroidism before the age of 60 is associated with loss of labor market income and an 89% increased risk of receiving a disability pension.