Association between pneumococcal pneumonia and venous thromboembolism in hospitalized patients: A nationwide population-based study

Abstract

Background and objectives This was a nationwide population-based retrospective cohort study to investigate the risk of developing deep-vein thrombosis (DVT) and pulmonary embolism (PE) in patients with a pneumococcal pneumonia. Methods We analysed data from 1998 to 2010 from the Taiwan National Health Insurance Database. The follow-up period was extended to the end of 2011. We identified patients with pneumococcal pneumonia and selected a comparison cohort matched for age, sex and diagnosis year at a ratio of one pneumococcal pneumonia patient to four control patients. We analysed the risks of DVT and PE by using Cox proportional hazards regression models, including gender, age and comorbidities. Results In total, 18-928 pneumococcal pneumonia patients and 75-712 controls were included in the study. The risks of developing DVT and PE were 1.78-fold (95% CI: 1.39-2.28) and 1.97-fold (95% CI: 1.43-2.72), respectively, in patients with pneumococcal pneumonia compared to the control cohort after adjusting for age, gender and comorbidities. The increased risks of DVT and PE were significant in patients who exhibited any comorbidity. The incidences of DVT and PE were highest in the first 4 weeks after pneumonia and remained slightly elevated from 13 weeks to 2 years after acute infection. Conclusion Pneumococcal pneumonia should be considered a risk factor for DVT and PE, even after the patient has recovered from the acute infection. Patients with pneumococcal pneumonia have a 1.78-fold and 1.97-fold risk to develop a DVT and PE, respectively in comparison with control cohort. The risk was particularly high in the first 4 weeks and in patients with comorbidities. See Editorial, page 695