Seasonal versus perennial allergic rhinitis: drug and medical resource use patterns.

BACKGROUND: There are no published studies that have compared the medical costs of patients with seasonal and perennial allergic rhinitis symptomatology.
OBJECTIVES: The objectives of this study were to develop an algorithm for classifying patients into seasonal and perennial groups based on their patterns of allergy medication use and then compare the epidemiology and economics of the two groups.
METHODS: Data for the study were obtained from the 1996 to 1998 MarketScan databases containing linked inpatient, outpatient, and pharmaceutical claims for approximately 2 million covered lives annually. Patients were classified into seasonal allergic rhinitis (SAR) or perennial allergic rhinitis (PAR) groups based on their pattern of allergy medication use over the course of 1 year and then compared using descriptive methods.
RESULTS: Seventy-nine percent of the total study sample (80534 allergy patients) was classified as SAR and 21% as PAR. PAR patients were found to have higher mean levels of allergy-related outpatient payments (US dollars 568 vs. US dollars 471) and higher mean costs for second-generation antihistamines (US dollars 552 vs. US dollars 162). PAR patients also had higher levels of comorbidities (asthma, sinusitis, depression, and migraine), higher numbers of concomitant medications (multiple second-generation antihistamines, nasal steroids, other antihistamines, asthma medications, and ophthalmic decongestants), and more immunization encounters.
CONCLUSIONS: Approximately 21% of allergic rhinitis patients have perennial symptoms as reflected in their patterns of medication use. Perennial patients have significantly higher allergy-related health-care costs and rates of comorbidities and greater use of concomitant medications. These distinct clinical and resource use profiles may have implications for therapy choices in the cost-effective management of perennial allergic rhinitis patients.