Bruneau J, Lamothe F, Franco E, Lachance N, Désy M, Soto J, Vincelette J
Department of Psychiatry, University of Montreal, Quebec, Canada.
Am J Epidemiol. 1997 Dec 15;146(12):994-1002. doi: 10.1093/oxfordjournals.aje.a009240.
Needle exchange programs (NEPs) are designed to prevent human immunodeficiency virus (HIV) transmission among injection drug users. Although most studies report beneficial effects in terms of behavior modification, a direct assessment of the effectiveness of NEPs in preventing HIV infection has been lacking. A cohort study was conducted to assess the association between risk behaviors and HIV seroprevalence and seroincidence among injection drug users in Montreal, Canada. The association between NEP use and HIV infection was examined in three risk assessment scenarios using intensive covariate adjustment for empirical confounders: a cross-sectional analysis of NEP use at entry as a determinant of seroprevalence, a cohort analysis of NEP use at entry as a predictor of subsequent seroconversion, and a nested case-control analysis of NEP participation during follow-up as a predictor of seroconversion. From September 1988 to January 1995, 1,599 subjects were enrolled with a baseline seroprevalence of 10.7%. The mean follow-up period was 21.7 months. The adjusted odds ratio for HIV seroprevalence in injection drug users reporting recent NEP use was 2.2 (95% confidence interval 1.5-3.2). In the cohort study, there were 89 incident cases of HIV infection with a cumulative probability of HIV seroconversion of 33% for NEP users and 13% for nonusers (p < 0.0001). In the nested case-control study, consistent NEP use was associated with HIV seroconversion during follow-up (odds ratio = 10.5, 95% confidence interval 2.7-41.0). Risk elevations for HIV infection associated with NEP attendance were substantial and consistent in all three risk assessment scenarios in our cohort of injection drug users, despite extensive adjustment for confounders. In summary, in Montreal, NEP users appear to have higher seroconversion rates then NEP nonusers.
针头交换项目（NEPs）旨在预防注射吸毒者之间的人类免疫缺陷病毒（HIV）传播。尽管大多数研究报告了在行为改变方面的有益效果，但一直缺乏对针头交换项目预防HIV感染有效性的直接评估。在加拿大蒙特利尔，开展了一项队列研究以评估注射吸毒者的风险行为与HIV血清阳性率及血清转换率之间的关联。在三种风险评估情形下，通过对经验性混杂因素进行密集协变量调整，研究了使用针头交换项目与HIV感染之间的关联：将入组时使用针头交换项目作为血清阳性率的一个决定因素进行横断面分析；将入组时使用针头交换项目作为后续血清转换的一个预测因素进行队列分析；将随访期间参与针头交换项目作为血清转换的一个预测因素进行巢式病例对照分析。从1988年9月至1995年1月，共纳入1599名受试者，基线血清阳性率为10.7%。平均随访期为21.7个月。报告近期使用针头交换项目的注射吸毒者中，HIV血清阳性率的调整优势比为2.2（95%置信区间1.5 - 3.2）。在队列研究中，有89例HIV感染新发病例，使用针头交换项目者的HIV血清转换累积概率为33%，未使用者为13%（p < 0.0001）。在巢式病例对照研究中，持续使用针头交换项目与随访期间的HIV血清转换相关（优势比 = 10.5，95%置信区间2.7 - 41.0）。在我们的注射吸毒者队列中，尽管对混杂因素进行了广泛调整，但在所有三种风险评估情形下，与参与针头交换项目相关的HIV感染风险升高都很显著且一致。总之，在蒙特利尔，使用针头交换项目者的血清转换率似乎高于未使用者。
