Depression is associated with subsequent risk of pleural empyema

Background: Respiratory system infections are prevalent in patients with depression. However, it remains unclear if patients with depression are at an increased risk of developing pleural empyema. Methods: We conducted a retrospective cohort study using data from the National Health Insurance Research Database of Taiwan. The depression group included 42,283 newly diagnosed patients between 2000 and 2012. The comparison group included the same number of individuals without depression, frequency matched for age, sex, comorbidities, and the year of diagnosis. The occurrence of pleural empyema was monitored until the end of 2013. Results: The overall incidence of pleural empyema was 1.32-fold higher in the depression group than in the comparison group (3.94 versus 2.97 per 10,000 person-years), with an adjusted hazard ratio of 1.33 (95% confidence interval, 1.27−1.40). Stratified analyses by age, sex, and comorbidity revealed that the crude and adjusted hazard ratios of pleural empyema associated with depression were significant in all subgroups. The 30-day mortality for pleural empyema was higher, but not significantly, in the depression group compared to the comparison group (10.7% versus 6.4%, adjusted odds ratio = 2.23, 95% confidence interval, 0.77−6.49). Conclusion: An association between depression and the development of pleural empyema may exist; however, more evidence is required to support this association. The reviews of this paper are available via the supplemental material section.