目標：本研究主要於減害計畫未全面實施前分析靜脈注射藥癮者參與「清潔針具交換計畫」及「替代療法」的意願及其影響因子，並建議減害措施可行模式。 方法：95年2至3月以分層隨機抽樣方式選取臺中監獄、雲林及嘉義戒治所靜脈注射藥癮者樣本共計1206人，進行橫斷式問卷調查。 結果：本研究發現有85.2%藥癮者表達傾向參加清潔針具交換計畫意願；93%的藥癮者表示願意參加替代療法。此外，羅吉斯迴歸分析發現「對清潔針具交換計畫之信念」、「識別卡片保障」、「藥癮同儕影響」及「配偶或性伴侶影響」等變項會影響未來加入清潔針具交換計畫意向；而「對替代療法之信念」、「替代療法自費程度」及「配偶或性伴侶影響」則是未來參加替代療法之顯著影響因子。 結論：推動減害措施除應有消除靜脈注射藥癮者對執法人員疑慮的配套措施外，更應宣導減害計畫對降低愛滋病感染之成效及美沙冬治療戒 毒之效能，透過藥癮者之社會網絡，推動同儕衛教並減輕自費者參加替代療法之負擔。

Objectives: The purpose of this study was to analyze the factors which influence the willingness of injection drug users to participate in needle exchange and substitution therapy programs while both programs are still experimental. Methods: The multi-layer random sampling method was used in a cross-sectional survey conducted between February and March 2006, in which 1,206 samples were collected at the Yunlin and Chia-I Drug Abstention and Treatment Center of the Taichung Prison. Results: Of the injection drug users, 85.2% and 93% were willing to participate in needle exchange and substitution therapy programs, respectively. Belief in the program, identification card protection, peer pressure, and their sexual partner’s encouragement were the factors which influenced willingness to participate in the needle exchange program, while belief in the program, the affordability of out-of-pocket volunteers, and their sexual partner’s encouragement were the factors which determined willingness to participate in the substitution therapy program. Conclusions: Implementing peer education through the social network of high risk groups, propagating the benefits of these programs, eliminating the financial burden of substitution therapy for those out-of-pocket volunteers, and working together with law enforcement officials as a cohesive group may facilitate the overall implementation of the Harm Reduction Program.