AB037. Drug-related costs of rhinitis in Australia: a NostraData cross-sectional study of pharmacy ​​purchases​

Background: Intranasal corticosteroids (INS) are a first-line therapy for rhinitis according to all international clinical guidelines for rhinitis. Although many added treatments are not recommended, the use of multiple therapies to control symptoms is frequent, as patients often continue to experience debilitating symptoms while on medication. Previous estimates of multiple therapy prescriptions may have been too conservative, as most rhinitis therapies are also available over-the-counter (OTC). This may affect the cost burden of rhinitis treatment. To investigate the extent of multiple therapy use to treat rhinitis in Australia, using doctor prescriptions and OTC medication; and to assess the additional cost incurred by multiple therapy use.

Methods: This was a historical cohort study of pharmacy-related claims from NostraData, Australia. We examined all rhinitis therapy purchases (antihistamines, INS, combination treatments of both such as Dymista, non-steroidal nasal sprays, leukotriene receptor antagonists (LTRA), eye drops for allergic conjunctivitis, oral steroids and systemic steroids) from 909 pharmacies, including OTC and prescription drugs. We used therapies purchased at the same transaction to assess the proportion of multiple therapy purchases and their cost.

Results: A total of 4,247,193 pharmacy transactions including rhinitis therapies were analysed; 4% of transactions included multiple rhinitis therapy classes. The average transaction cost was 12.82 EUR for single therapy purchases and 26.72 EUR for multiple therapy purchases. 15% of single therapy purchases were INS, for an average cost of 20.68 EUR. The most frequent additions to INS therapy were antihistamine (74%) and non-steroidal nasal spray (10%). About 94% of antihistamine and 97% of non-steroidal nasal spray purchased as add-on therapy to INS were bought over-the-counter. The average cost of INS & antihistamine and INS & non-steroidal nasal spray transactions was 30.65 and 26.57 EUR, respectively.

Conclusions: Rhinitis patients in Australia frequently purchase OTC antihistamine and non-steroidal nasal spray in addition to the recommended INS therapy. This suggests that INS alone do not provide adequate symptom control. This practice comes at a high financial cost for patients. This study highlights the need for a new and more cost effective treatment option for rhinitis.

Keywords: Rhinitis; intranasal corticosteroids (INS); costs