Di Bona D, et al. - Researchers developed a Markovian Model in this study to evaluate which amongst SCIT (subcutaneous immunotherapy) or SLIT (sublingual immunotherapy) is a more cost-effective form of allergen immunotherapy (AIT) for grass pollen. A hypothetical cohort comprising adult patients with moderate-to-severe rhino-conjunctivitis with or without allergic asthma was assessed. For SLIT (tablets, Grazax and Oralair) or SCIT (many currently available products, plus indirect non-medical costs, such as travel and productivity costs) in addition to pharmacological therapy, long-term effects were noted over an assumed 9-year horizon, to determine cost-effectiveness. In the base-case, a slightly greater expense related to SCIT was reported, but SCIT showed greater effectiveness as compared with SLIT, being the most cost-effective choice [ICER (incremental cost-effectiveness ratio) for SCIT, €11,418; ICER for SLIT, €15,212]. According to the findings, AIT may afford a cost-effective option in daily practice only for those patients with grass pollen allergy who show low discontinuation rates. SCIT, which is less influenced by this limitation compared with SLIT, appears the most cost-effective AIT form.