Allergen-specific immunotherapy prescription patterns in veterinary practice: a US population-based cohort study.

BACKGROUND: Poor adherence to continuing allergen-specific immunotherapy treatment (ASIT) may be an issue in veterinary medicine. No studies describe how allergen tests are used in general veterinary practice, including the percentage of patients that receive ASIT after allergen testing.

HYPOTHESIS/OBJECTIVES: Assess veterinary ASIT patterns in United States general practices.

ANIMALS: Dogs (n = 2,557) and 121 cats allergen-tested at 177 hospitals (173 general practice and four specialty practices) in 44 states.

METHODS: Invoiced service descriptions of allergen tests and ASIT orders were retrieved from an aggregated database of veterinary practices.

RESULTS: In general practice, 42% (992 of 2,360) of patients did not begin ASIT after allergen testing. ASIT was not refilled for 29% (398 of 1,368) of patients after the initial order. ASIT was initiated and refilled more often in dogs (56.6%, 71.4%, respectively) than cats (38%, 67.4%). Specialty practice patients had the highest ASIT initiation (94.4%) and refill (92.7%) percentages in comparison to general practices (P < 0.001). Size, age, geographical region and type of practice were associated with whether dogs were started on ASIT. Geographical region was also associated with refilling a prescription for ASIT, which was considered to be evidence of adherence to continuing treatment.

CONCLUSIONS AND CLINICAL IMPORTANCE: Almost one third of clients failed to continue ASIT beyond the initial order, which is a much shorter duration of therapy than the 12 months recommended for determining ASIT efficacy. A large number of general practice patients did not begin ASIT after allergen testing, likely due to differences in how clinicians in general and dermatology practices use allergen tests.