National trends in asthma visits and asthma pharmacotherapy, 1978-2002

Research is limited on physicians' compliance with recent clinical guidelines for asthma treatment.

Our purpose was to investigate the relationships among clinical guidelines, asthma pharmacotherapy, and office-based visits through use of nationally representative data.

Nationally representative data on prescribing patterns by office-based US physicians were extracted from the National Disease and Therapeutic Index. We tracked 1978-2002 trends in the frequency of asthma visits and patterns of asthma pharmacotherapy, focusing on the use of controller and reliever medications.

The estimated annual number of asthma visits in the United States increased continuously from 1978 through 1990 (18 million visits); since 1990, it has remained relatively stable. Controller medication use increased 8-fold between 1978 and 2002, inhaled corticosteroids manifesting the biggest increases. The use of reliever medications, particularly short-acting oral beta(2)-agonists, decreased modestly over this period. The aggregate use of controllers (83% of visits) superseded that of relievers (80%) for the first time in 2001. Improved appropriateness of asthma pharmacotherapy was also suggested by an increase in the controller-to-reliever ratio, which reached 92% in 2002. Xanthines, which once dominated asthma therapy (63% of visits in 1978), were used in only 2% of visits in 2002. More recent drug entrants have been adopted rapidly, single-entity long-acting inhaled beta(2)-agonists being used in 9% of visits and leukotriene modifiers in 24% of visits in 2002.

Asthma pharmacotherapy has changed extensively in the past 25 years. Practices over the last decade are increasingly consistent with evidence-based guidelines. These changes in medication use might have contributed to the lack of a recent increase in asthma visits.