Compliance With Subcutaneous Immunotherapy Appointments in an Urban Tertiary Care Setting

Subcutaneous immunotherapy (SCIT) is an effective treatment for allergic disease such as allergic rhinitis and asthma. Reported adherence rates to SCIT have been low, ranging between 50% and 89%. This study sought to evaluate compliance to SCIT in an urban "safety net," tertiary care center, and to evaluate for disparities in compliance based upon insurance and socioeconomic status.

A retrospective chart review of SCIT patients between 2003 and 2016 was performed. Demographic data, insurance carriers, and comorbidities were collected. Compliance was evaluated on treatment adherence (percentage of injections administered/scheduled appointments). Statistical analysis was performed using R statistical software. Linear regression analysis was performed to compare compliance to the variables, asthma, duration of therapy, payor, and age. Analysis of variance was used to compare mean compliance between payor groups.

Two hundred five patients met our inclusion criteria and 28 were excluded. Insurance composition was Medicaid (67, 33%), Medicare (18, 9%), Health Safety Net (HSN) in Massachusetts (33, 16%), and commercial payors (82, 42%). Linear regression demonstrated that age, duration of therapy, and asthma status were not related to the percentage of missed doses ( P > .05). Payor status was statistically predictive of missed doses ( P = .02). When comparing average percentage of missed immunotherapy shots, Medicaid patients missed the most 34.2%, followed by Medicare 24.4%, commercial insurance 19.9%, and HSN in Massachusetts 18.5% ( P ≤ .02).

In a cohort of patients at a tertiary care "safety-net" center serving a low-income population, compliance to SCIT was found to be overall high but lower in the Medicaid population.