Inappropriate use of inhaled short acting beta-agonists and its association with patient health status

Abstract

Background: Despite the widespread distribution of guidelines on the proper use of inhaled asthma medication, the overuse of short acting bronchodilators (SABs) persists. This study aims to examine how inhaled asthma medications are used in the US and to examine whether inappropriate use of inhaled SABs is associated with poor patient health.

Research design and methods: The study design was a retrospective analysis of the Medical Expenditure Panel Survey (MEPS) for asthmatic patients 5 years or older who had used SAB medication during the period from 1996 through 2000. Use of SAB medication was defined as inappropriate when a patient inhaled more than 225 defined daily doses (DDDs) of SABs but less than 45.625 DDDs of corticosteroids per year. Health status was evaluated using survey respondents' perceptions on a 5-point Likert scale. Five functional limitations (activities of daily living, instrumental activities of daily living, walking, social function, and cognitive function) were rated on a dichotomous scale.

Results: A total of 2386 asthmatic patients were identified as having used a SAB in the period 1996 through 2000. Of these, 272 (11.4%) used excessive doses of SABs, and of this group of excessive users, 151 (55.5%) underused corticosteroids. Compared to appropriate users of SAB medication, inappropriate users had lower perceptions of their overall health (adjusted mean: 3.21 vs. 2.94, p<0.05) and mental health (adjusted mean: 2.39 vs. 2.13, p<0.05). They were also at an increased risk of limitations in walking (relative risk [RR]: 1.76, 95% confidence interval [CI]:1.15-2.71) and in cognitive function (RR: 2.32, 95% CI: 1.37-3.93).

Conclusion: Despite the national guidelines concerning the proper use of inhaled asthma medication, over-reliance on SAB medication and under-use of corticosteroids persists in the US. Those not using asthma medication according to the guidelines had poor perceptions of their health and were subject to an increased risk of limitations in walking and cognitive function.