Table 2

Adjusted rate ratio of fatal and non-fatal acute myocardial infarction for inhaled β2 agonist use during the year before the index date

Cases (n=1127)Controls (n=10766)Crude rate ratioRate ratio95% CI
*Adjusted (after age matching) for sex, number of prescriptions for oral corticosteroids, nasal corticosteroids, inhaled corticosteroids, oral β2 agonist, nebulised β2 agonist, and xanthines in the year before the index date, and presence of cardiovascular risk factors (angina, hypertension, congestive heart failure, arrhythmia, hyperlipidemia and diabetes) in the year before the index date.
†Rate ratio per additional 10 metered dose inhalers (MDIs) of inhaled β2 agonist.
‡Use of inhaled β2 agonist in the 2 months before the index date.
§Current use of inhaled β2 agonist with no other β2 agonist use of any form during the year before the index date.
One year before index date
    No use (%)57.458.01.001.00Reference
    Any use (%)42.642. to 1.23
        1–17 MDIs (%) to 1.21
        ≥18 MDIs (%) to 1.83
    Mean (SD) no MDIs†3.2 (6.9)2.9 (6.1) to 1.23
Current use‡
    Any current use (%) to 1.33
    New use (%)§ to 1.80
    First time use (%) to 2.00