Health and Economic Outcomes of Home Maintenance Allergen Immunotherapy in Select Patients with High Health Literacy during the COVID-19 Pandemic: A Cost-Effectiveness Analysis During Exceptional Times

Shaker, Marcus S.; Mosnaim, Giselle; Oppenheimer, John; Stukus, David; Abrams, Elissa M.; Greenhawt, Matthew

Abstract Background Allergen immunotherapy is safe and effective but is typically administered under strict clinic observation to mitigate risk of a systemic reaction to immunotherapy (SRIT). However, in the setting of the global COVID-19 pandemic, alternative care models should be explored. Objective To evaluate the cost-effectiveness of home immunotherapy self-administration (HITSA) in a highly idealized circumstance for provision of maintenance allergen immunotherapy in a shelter-in-place or other scenarios of unforeseen reduction in non-essential medical services. Methods Markov modeling was used to compare in-office clinic allergen immunotherapy in selected patients using cohort analysis and microsimulation from the societal and healthcare perspectives. Results Assuming similar SRIT rates, HITSA was found to be a cost-effective option with an incremental cost-effectiveness ratio (ICER) of $44,554/QALY (quality adjusted life year) when considering both incremental epinephrine autoinjector (EAI) costs and COVID-19 risks. Excluding EAI costs, HISTA dominated other options. However, outside of pandemic considerations, HITSA was not cost effective (ICER $198,877,286) at annual EAI costs above $287. As the incremental HITSA SRIT rate increased above 15%, clinic AIT was the most cost-effective strategy. Excluding both pandemic risks and risk of motor vehicle accident fatality from round-trip clinic transit, clinic AIT dominated other strategies. Clinic AIT was the more cost-effective option at very high fatality relative risk for HITSA or at very low annual risk of contracting COVID-19. Conclusion Under idealized assumptions HITSA can be a safe and cost-effective option during a global pandemic in appropriately selected patients provided home rates of SRIT remain stable.