Adherence and Clinical Outcome of Sublingual Immunotherapy for Japanese Cedar Pollinosis.

Sublingual immunotherapy (SLIT) for Japanese cedar pollinosis is known to be effective. However, better SLIT adherence is needed to improve its safety and efficacy. 　Purpose: The purpose of this study was to evaluate SLIT adherence and its influence on clinical outcome. 　Methods: We conducted a detailed survey of 132 patients who have been receiving SLIT for 2 years on adherence at each visit using both questionnaires and direct calculation from prescription. Questionnaires on total symptoms using the visual analog scale (VAS), face scale, and total nasal symptom medication score (TNSMS) were obtained at the peak season for Japanese cedar pollinosis. 　Results: Good adherence by prescription for 2 years was observed in 83.1% ± 11.7% of patients. The adherence in the second year (80.8% ± 13.6%) was lower than that in the first year (88.5% ± 9.8%). However, adherence by questionnaire was 13.5% higher than that by prescription. VAS of total symptoms and adherence did not correlate; however, evaluations by VAS, face scale, and TNSMS were significantly improved if the adherence cut-off value was set to 70% or 75%. 　Conclusion: Our results suggest that SLIT adherence for Japanese cedar pollinosis is high and adequate adherence is required for better efficacy.