BACKGROUND:US national guidelines recommend assessingshort-actingbeta-agonist(SABA) medication use as a marker ofasthmaseverity and control. However, therelationshipbetweenrecentSABA use andasthmaexacerbationsis not currently known.OBJECTIVE:To evaluate the proximalrelationshipbetween the type and frequency of SABA use andasthma-related outcomes.METHODS:We evaluated SABA use among patients withasthmaages 5 to 56 years who were members of a large health maintenance organization in southeast Michigan. Frequency of use was estimated from pharmacy data assessing the timing and amount of SABA fills. Cox proportional hazards models were used to examine the prospectiverelationshipbetween average daily SABA use for 3 months and outcomes associated with poorasthmacontrol (ie, oral corticosteroids use,asthma-related emergency department visits, andasthma-related hospitalizations). We separately accounted for SABA metered-dose inhaler (MDI) and SABA nebulizer use.RESULTS:Of the 2,056 patients who met study criteria, 1,569 (76.3%) had used a SABA medication in their baseline year. After adjusting for potential confounders, SABA nebulizer use was associated withasthma-related emergency department visits (adjusted hazard ratio [aHR], 6.32; 95% confidence interval [CI], 2.38 to 16.80) andasthma-related hospitalizations (aHR, 21.62; 95% CI, 3.17 to 147.57). In contrast, frequency of SABA MDI use was not associated with these outcomes.CONCLUSIONS:Frequency of SABA use during a 3-month period was associated with poorasthmaoutcomes. Therelationshipwith poorasthmaoutcomes was strongest for SABA nebulizer use, suggesting that the type of SABA used is also of prognostic importance.
