Asthma'chronic obstructive pulmonary disease overlap syndrome associated with risk of pulmonary embolism

Abstract

Purpose We conducted a cohort study to clarify this relationship between asthma'chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and pulmonary embolism (PE). Methods From the National Health Insurance Research Database of Taiwan, we identified patients who had a diagnosis of asthma and a diagnosis of COPD (defined as ACOS) and concurrent treatment between January 1999 and December 2009 (ACOS cohort: n = 14,150; non- ACOS cohort: n = 55,876). Cox proportional hazards regression analysis was performed to determine the adjusted hazard ratios (aHRs) for PE of the ACOS cohort compared with the non-ACOS cohort. Results Comparing the ACOS cohort with the non-ACOS cohort, the aHR of PE was 2.08 (95% confidence intervals [CIs]: 1.56'2.76). The risk of PE was higher in ACOS cohort than non- ACOS cohort, regardless of age, sex, comorbidity, inhaled corticosteroids (ICSs) and oral steroids (OSs) used. For ages ranging from 20 to 65 years, the aHR of PE was 2.53 (95% CI: 1.44'4.44) in the ACOS cohort.ACOS patients using ICSs (aHR: 1.97, 95% CI: 1.29' 3.01) or OSs (aHR: 1.97, 95% CI: 1.46'2.65), the risk of PE was higher than in the non- ACOS cohort. The risk of PE increased with the number of outpatient visits and hospitalizations necessitated, ranging from 2.32 (95% CI: 1.54'3.52) in patients having 3'9 visits to 4.20 (95% CI: 2.74'6.44) for those having >9 visits. Conclusions ACOS is associated with increased risk of PE, particularly patients with a high frequency of AE-even in young adults or people without comorbidities.