Centre on Drug Policy and Evaluation, St. Michael's Hospital, Toronto, Canada.
Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada.
Drug Alcohol Rev. 2023 Sep;42(6):1504-1516. doi: 10.1111/dar.13687. Epub 2023 Jun 15.
We sought to identify latent profiles of polysubstance use patterns among people who inject drugs in three distinct North American settings, and then determine whether profile membership was associated with providing injection initiation assistance to injection-naïve persons.
Cross-sectional data from three linked cohorts in Vancouver, Canada; Tijuana, Mexico; and San Diego, USA were used to conduct separate latent profile analyses based on recent (i.e., past 6 months) injection and non-injection drug use frequency. We then assessed the association between polysubstance use patterns and recent injection initiation assistance provision using logistic regression analyses.
A 6-class model for Vancouver participants, a 4-class model for Tijuana participants and a 4-class model for San Diego participants were selected based on statistical indices of fit and interpretability. In all settings, at least one profile included high-frequency polysubstance use of crystal methamphetamine and heroin. In Vancouver, several profiles were associated with a greater likelihood of providing recent injection initiation assistance compared to the referent profile (low-frequency use of all drugs) in unadjusted and adjusted analyses, however, the inclusion of latent profile membership in the multivariable model did not significantly improve model fit.
We identified commonalities and differences in polysubstance use patterns among people who inject drugs in three settings disproportionately impacted by injection drug use. Our results also suggest that other factors may be of greater priority when tailoring interventions to reduce the incidence of injection initiation. These findings can aid in efforts to identify and support specific higher-risk subpopulations of people who inject drugs.
我们试图在三个不同的北美地区确定注射毒品者中多物质使用模式的潜在特征，并确定特征成员身份是否与向注射毒品新手提供注射起始协助有关。
利用来自加拿大温哥华、墨西哥蒂华纳和美国圣地亚哥的三个关联队列的横断面数据，根据最近（即过去 6 个月）的注射和非注射药物使用频率，分别进行潜在特征分析。然后，我们使用逻辑回归分析评估多物质使用模式与最近的注射起始协助提供之间的关联。
基于拟合度和可解释性的统计指标，为温哥华参与者选择了 6 类模型，为蒂华纳参与者选择了 4 类模型，为圣地亚哥参与者选择了 4 类模型。在所有环境中，至少有一个特征包括高频率的冰毒和海洛因多物质使用。在温哥华，与未调整和调整后的分析相比，在多个模型中，与参考特征（所有药物低频率使用）相比，几个特征与提供最近的注射起始协助的可能性更大，但在多变量模型中包含潜在特征成员身份并没有显著提高模型拟合度。
我们在三个受注射药物使用影响不成比例的地区确定了注射毒品者中多物质使用模式的共性和差异。我们的结果还表明，在制定减少注射起始发生率的干预措施时，其他因素可能更为重要。这些发现可以帮助识别和支持特定的高风险注射毒品人群。
