Prolonged duration and dose of pegylated interferon and ribavirin after 48 weeks of treatment to maximinze SVR in HCV genotype 1-infected patients is recommended. In Taiwan, payment of treatment from National Health Insurance system is limited to 24 weeks therapy. We aimed to determine the feasibility of different courses of treatment with pegylated interferon plus ribavirin in patients infected with HCV genotype 1. From March 2003 to March 2008, 91 patients with HCV genotype 1 received pegylated interferon weekly as well as weigh-base ribavirin daily for either 24(n=33), 36(n=28) or 48(n=30) weeks. Normalization of ALT and sustained viral response 24 weeks after end of treatment were recorded and analyzed. Cost effectiveness and adverse drug effect were also recorded. Results: The end-of-follow-up response was 36.3% for 24 weeks treatment, 57.1% for 36 weeks treatment, and 63.3% for 48 weeks treatment. The rate of ALT normalization was 70% for 24 weeks, 82.1% for 36 weeks, and 76.7% for 48 weeks. Twenty-four weeks of therapy was inferior to 48 weeks in achievement of sustained viral response rates (p<0.05). There was no significant difference in the SVR rate between patients treated for 36 weeks and 48 weeks. We found an association between early fibrosis stage and therapy for more than 36 weeks with more durable treatment effects. Conclusion. The efficacies of 36 weeks pegylated interferon plus ribavirin treatment for patients infected with HCV genotype 1 is comparable to 48 weeks therapy. Larger studies are needed to elucidate the cost-effectiveness of these therapies. 許多研究發現感染慢性C型肝炎病毒基因型第一型者對於治療的反應較差，目前國內外針對慢性C型肝炎病毒基因型第一型者的治療共識，即為使用甲型長效型干擾素加上足夠劑量（依病患體重而定）的Ribavirin及48週的標準療程，才能有效提高治療的成功率。近年來則是考量治療成效、副作用及治療成本因素，強調依各種影響治療成功的因素來制定個人化之療程。本研究乃採取回溯性病歷回顧方式，針對中部某醫學中心之早期慢性C型肝炎病毒基因型第一型治療患者，分別比較接受24週、36週折衷療程及48週治療療程進行療效分析，並試著找出影響治療成效的關鍵因素。本研究分析結果發現，依不同的療程所達到的病毒清除率(SVR)分別為24週(36.3%)、36週(57.1%)及48週(63.3%)，達到持續性生化反應的比率則為24週(70%)、36週(82.1%)及48週(76.7%)，就病毒清除率(SVR)的部份48週的療程優於24週療程(P<0.05)，達到持續性生化反應的部份36週優於24週(P<0.05)，而探究治療成功的影響因素與患者肝臟纖維化嚴重程度及治療療程時間具有相關性(P<0.05)，治療所產生的副作用未因療程的長短而增加發生比率。結論：慢性C型肝炎病毒基因型第一型患者使用長效型干擾素加上Ribavirin治療48週能達到很好的治療成效，而36週的折衷療程亦能達到高比率的持續性生化反應，相較於48週的治療療程，能減少治療成本的支出及承受副作用的時間，藉此研究結果，可作為慢性C型肝炎病毒基因型第一型患者治療療程之選擇。
