Economic evaluation of sublingual immunotherapy vs symptomatic treatment in adults with pollen-induced respiratory allergy: the Sublingual Immunotherapy Pollen Allergy Italy (SPAI) study

Background: Few data are available on the pharmacoeconomic aspects of immunotherapy. Objective: To evaluate, from the health care system and societal perspectives, the costs and consequences of sublingual immunotherapy (SLIT) added to pharmacotherapy compared with drugs alone for respiratory allergy. Methods: This study compared costs, clinical outcomes, and cost-effectiveness ratios of 2 strategies in the management of allergic rhinitis and asthma, namely, SLIT associated with pharmacotherapy and pharmacotherapy alone (no SLIT). A decision tree was developed and populated with epidemiologic and resource utilization data concerning approximately 2,200 patients. Direct costs included visits, tests, pharmacotherapy, immunotherapy, and hospitalizations. Indirect costs and out-of-pocket drugs were also included. Outcome was calculated as the number of improved patients and asthma cases avoided at 6 years. Sensitivity analysis was performed by varying costs and epidemiologic data. Results: SLIT improved the symptoms of 399 of 1,000 patients and prevented asthma in 229 of 1,000 patients compared with drugs alone. For SLIT added to pharmacotherapy and pharmacotherapy alone, the direct cost per patient at more than 6 years was EURO2,400 and EURO3,026, whereas the indirect cost was EURO1,913 and EURO3,400. Conclusion: From both perspectives and for both effectiveness end points, SLIT is less expensive and more effective than pharmacotherapy alone.