Quality-of-Life Outcomes in Patients who Underwent Subcutaneous Immunotherapy and Sublingual Immunotherapy in a Real-World Clinical Setting

Abstract

Objective To compare changes in quality of life (QOL) that resulted from sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) in a real-world clinical setting. Background SLIT is established as a viable alternative to SCIT for the treatment of allergic rhinitis. Although comparative trials are increasingly available, few studies have examined QOL outcomes between these two treatments. Methods One hundred and five participants who underwent immunotherapy for airborne allergies were enrolled in this prospective, single-center study. Forty participants completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) at initiation of therapy, after 6 months, and after 1 year of therapy. Only patients with complete time points were included in the ultimate analysis. Twenty-nine of these participants underwent SCIT and 11 underwent SLIT. The effects of age, sex, and asthma history were also examined. Results The participants in both groups demonstrated improvements in QOL regarding allergic rhinoconjunctivitis over the study period. However, the change in the RQLQ score from both baseline to 6 months and baseline to 1 year was only statistically significant in the SCIT group (p = 0.002, 6 months and 1 year). The participants in the SCIT group also demonstrated statistically significant improvement from baseline to 1 year in the specific domains of practical and emotional functioning, nasal symptoms, non-nasal/eye symptoms, and sleep. After 1 year, both SCIT and SLIT demonstrated a minimally important difference from baseline in the overall RQLQ score. Age <35 years in the SCIT group had a significant positive impact on QOL improvement (p = 0.038). Conclusion Although improvements in QOL were noted in both groups, changes in overall scores and the majority of domains only achieved statistical significance in the SCIT group. A small study population and difficulties adhering to immunotherapy dosing schedules in the SLIT group may be contributing factors.