Comparison of costs of sublingual immunotherapy and drug treatment in grass-pollen induced allergy: results from the SIMAP database study.

Objectives: This analysis is focused on the comparison of costs of allergic rhinitis (R) alone or with allergic asthma (R + A) in grass pollen allergy, for subjects treated with sublingual immunotherapy (SLIT) and symptomatic drugs, versus standard care controls.

Methods: The SIMAP (Sublingual IMmunotherapy in Allergic Patients) study is a longitudinal observational database operated by a network of Allergy centers. Patients suffering from grass pollen allergy were included in this analysis and assigned to SLIT (plus drugs as needed) or to treatment with drugs alone. Outcome measures included use of medications, SLIT, visits and tests. Costs were assessed from the perspective of the Italian National Health Service; unit costs were obtained from published sources to produce an average cost/patient for the first year after enrolment.

Results: One hundred and two patients were analyzed. Demographics were comparable in the two groups. Overall per patient yearly cost of treatment was higher in SLIT patients, both in the whole sample (euro311 vs. euro180/patient), in the R (euro288 vs. euro116) and R + A (euro362 vs. euro230) subpopulations, with R + A patients generating more costs than R patients in both groups. Nevertheless considerable savings were obtained in the cost of symptomatic drugs (-22% for R; -34% for R + A) in SLIT patients.

Conclusions: Other studies have shown that SLIT can reduce the use of drugs for asthma and rhinitis, but this is the first time this outcome has been demonstrated in a routine care population (in the medical practice environment of an observational study) within the first year of treatment.