Poor Clinical Outcomes among Pneumonia Patients with Depressive Disorder

Background Some studies suggested that psychological stress may be associated with the severity and duration of infectious diseases. In this population-based study, we investigated associations between depressive disorder (DD) and pneumonia outcomes in Taiwan with a large-scale database from the National Health Insurance. Methods Our study defined 112,198 patients who were hospitalized with a principal diagnosis of pneumonia. We defined their admission date for treatment of pneumonia as the index date. Subsequently, we selected 2,394 patients with DD within 3 years prior to their index date and 11,970 matched patients without DD. We carried out separate conditional logistic regressions to explore the association of clinical pneumonia treatment outcome (ICU admission, use of mechanical ventilation, acute respiratory failure and in-hospital death) with previously diagnosed DD. Results Patients with DD had a significantly higher probability of an intensive care unit admission (18.1% vs. 12.9%; p <0.001), need for mechanical ventilation (21.9% vs. 18.1%; p <0.001) and in-hospital death (10.4% vs. 9.0%; p  = 0.025) than patients without DD. The study showed that pneumonia patients with DD were respectively 1.41- (95% CI: 1.25∼1.59, p <0.001), 1.28- (95% CI: 1.14∼1.43, p <0.001), and 1.17- times (95% CI: 1.01∼1.36, p  = 0.039) greater odds of being admitted to the ICU, need for mechanical ventilation, and in-hospital death than patients without DD after adjusting for monthly income, urbanization level, geographic region and Charlson Comorbidity Index score. Conclusions In conclusion, we found that pneumonia patients with DD were associated with poor treatment outcomes compared to patients without DD.