[Cost-effectiveness analysis of pre-seasonal medication for cedar pollinosis in Japan].

Pre-seasonal medication is recommended for cases of cedar pollinosis that are expected to manifest severe symptoms during the season, according to the standard clinical guideline in Japan. This study aims to appraise the value for money of additional costs that accompany the choice of pre-seasonal medication from payer's perspective. Based on the 12 reports of controlled clinical trials with Symptom Score (SS) and Medication Score (MS) comparing pre-seasonal medication with intra-seasonal symptomatic medication, 15 incremental cost-effectiveness ratios (ICERs) and 4 integrated ICERs of each group of targeted agents are estimated. Incremental effects are estimated by reading SS charts, and incremental costs are estimated by reading MS charts and using National Health Insurance Medical Fee Schedule and National Health Insurance Drug Price Standard. Estimated ICERs range from ¥322,195 per quality-adjusted life-year (QALY) to ¥57,088,063 per QALY. Integrated ICERs are: ¥1,128,286 per QALY for 2nd generation histamine H(1) receptor antagonists, ¥2,248,018 per QALY for leukotriene receptor antagonists, ¥2,692,911 per QALY for prostaglandin D(2) and thromboxane A(2) receptor antagonists, ¥1,150,943 per QALY for Th2 cytokine suppressors, and ¥1,291,341 per QALY for all agents. Pre-seasonal medication for cedar pollinosis is cost-effective regardless of the choice of the prophylactic agent among 2nd generation histamine H(1) receptor antagonists, leukotriene receptor antagonists, prostaglandin D(2) and thromboxane A(2) receptor antagonists, or Th2 cytokine suppressors, taking the suggested threshold of ¥5,000,000 per 1 QALY gain in Japan. The use of 2nd generation histamine H(1) receptor antagonists and Th2 cytokine suppressors are found more favourable.