Hormonal contraception and the risk of severe asthma exacerbation: 17-year population-based cohort study

Study (n=456,803 person-years) reports previous (incidence rate ratio [IRR] 0.94, 95% CI 0.92 to 0.97) and current (IRR 0.96, 95% CI 0.94 to 0.98) use of any hormonal contraceptive may reduce risk of severe asthma exacerbation in reproductive-age women compared with non-use.

Thorax