Asthma associated with increased odds of venous thromboembolism, pulmonary embolism, and deep vein thrombosis in observational studiesAsthma Linked to Higher Risk of Blood Clots in Observational Data

This meta-analysis evaluated the association between asthma and the risk of venous thromboembolism (VTE), pulmonary embolism (PE), and deep vein thrombosis (DVT). The study synthesized data from observational designs, including cohorts, case-control, and cross-sectional studies. The population consisted of patients with asthma, though the total sample size was not reported. Settings included various regions, with results stratified by geography.

The primary outcome measured the odds ratios for VTE components. Patients with asthma demonstrated a 1.61-fold higher odds of overall VTE (OR = 1.61; 95% CI: 1.45-1.77). Specifically, the odds of pulmonary embolism were 2.41-fold higher (OR = 2.41; 95% CI: 1.77-3.27), while deep vein thrombosis odds were 1.56-fold higher (OR = 1.56; 95% CI: 1.49-1.63).

Regional analysis indicated the highest risk in Asia (OR = 3.19; 95% CI: 2.06-4.96), followed by America (OR = 2.24; 95% CI: 1.55-3.24) and Europe (OR = 1.64; 95% CI: 1.49-1.81). Associations were strongest in cohort studies, where the odds ratio reached 4.21 (95% CI: 2.56-6.92). Safety data, adverse events, and tolerability were not reported in the included studies.

Key limitations include the reliance on observational designs, which preclude causal inference, and the lack of reported sample sizes. The authors note that absolute risks were not provided. Consequently, these results describe an association and should not be interpreted as evidence that asthma directly causes VTE or that specific clinical management changes are warranted without further prospective data.