An Investigation of Allergic Rhinitis, Asthma, and Medication Use in a Privately Insured Population

DESIGN: A retrospective analysis using medical and pharmacy claims data from 1994 and 1995. Prevalence rates of asthma and allergy and the mean number of prescription claims for these patients were calculated. Patients with both asthma and allergic rhinitis, asthma only, and those with allergic rhinitis only were compared. PATIENTS: Patients with allergic rhinitis or asthma in the 1994 MarketScan file, with a diagnosis of allergic rhinitis or two or more nonsedating antihistamine prescriptions or two or more nasal inhaled steroid prescriptions during the year. Asthma patients were identified by an asthma diagnosis and the presence of at least one beta-agonist prescription, or in the absence of an asthma diagnosis, by two or more beta-agonist prescriptions during the year. The final study population excluded those under 12 or over 60 years of age, who did not have prescription drug data in 1994 and 1995, and who were not continuously enrolled in 1995. RESULTS: Asthma was more prevalent in the allergic rhinitis population (10%) than in the general population. In addition, the rate of allergic rhinitis in the asthmatic population (44%) was much higher than the rate of allergic rhinitis in the overall population (11%). On average, patients with both conditions had approximately 30% more asthma prescriptions (10.9) than did those with asthma alone (8.4). Likewise, patients with both conditions also had approximately 31% more allergic rhinitis prescriptions (4.62) than did those with allergic rhinitis alone (3.52). CONCLUSION: The increase in medication use by people with both asthma and allergic rhinitis lends support to the idea that nasal inflammation is a marker for increasing dysfunction of the entire respiratory tract. Given the increased prevalence of these diseases, effective aggressive treatment would benefit a large segment of the population. As the link between allergic rhinitis and asthma continues to be established, it is probable that treatments for one condition could alleviate the coexisting condition.