Table 3

Crude and adjusted rate ratios of asthma hospitalisation for patterns of inhaled corticosteroid use during the year before the index date for the full and hospitalised cohorts

Inhaled corticosteroid use during the 1 year period before the index dateCasesControlsCrude rate ratioAdjusted* rate ratio (95% CI)
*In addition to matching, rate ratios are further adjusted for the number of dispensed prescriptions of theophylline, nebulised and oral β agonists, oral corticosteroids, and the number of canisters of inhaled β agonists, all dispensed during the year before the index date, as well as the number of asthma hospitalisations during the year before cohort entry, age, and sex.
Full cohort
Number of subjects389435399
Regular use (%)3.63.81.00Reference
Irregular use (%)26.918.61.661.73 (1.41 to 2.11)
Non use (%)69.577.61.091.28 (1.05 to 1.56)
Hospitalised cohort
Number of subjects188613636
Regular use (%)6.87.51.00Reference
Irregular use (%)35.027.21.651.69 (1.36 to 2.01)
Non use (%)58.265.31.351.59 (1.28 to 1.94)