Predictors of adherence to sublingual immunotherapy for Japanese cedar pollinosis: a prospective analysis

Background: Sublingual immunotherapy (SLIT) often has low adherence rates. Objective: To provide effective support for SLIT continuation, we investigated potential predictors of SLIT adherence through a prospective analysis of patient characteristics. We excluded evaluation of treatment effect and symptoms during treatment, aiming instead to identify predictors of later dropout or insufficient adherence due to indolence or forgetfulness using only information obtained at initial examination. Methods: We provided patients with a questionnaire and monitored self-reported adherence once every 6 months. Cas-es of dropout for clear reasons were excluded, but cases of dropout or insufficient adherence to SLIT for indolence or forgetfulness were included. Results: Fifty-three patients receiving SLIT were assessed. Nine patients dropped out after providing a clear reason. Thirty-four patients maintained good adherence. Seven patients continued SLIT but with insufficient adherence, while three patients discontinued SLIT for unclear reasons (indolence or forgetfulness) and these ten individuals were clas-sified as the poor-adherence group. Univariate analysis and multivariate logistic regression analysis of the good-ad-herence and poor-adherence groups showed age to be a significant predictor of SLIT adherence. Based on analysis of a receiver operating characteristic curve, age < 40.5 years was selected as the optimal cutoff value for predicting poor adherence to SLIT. Conclusion: To prevent treatment SLIT discontinuation on account of indolence or forgetfulness, the necessity of long -term treatment continuity should be communicated clearly prior to commencing treatment, especially for patients under 40 years of age.