Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada.
Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
PLoS One. 2021 Apr 19;16(4):e0249836. doi: 10.1371/journal.pone.0249836. eCollection 2021.
HIV-HCV coinfected individuals are often more deprived than the general population. However, deprivation is difficult to measure, often relying on aggregate data which does not capture individual heterogeneity. We developed an individual-level deprivation index for HIV-HCV co-infected persons that encapsulated social, material, and lifestyle factors.
We estimated an individual-level deprivation index with data from the Canadian Coinfection Cohort, a national prospective cohort study. We used a predetermined process to select 9 out of 19 dichotomous variables at baseline visit to include in the deprivation model: income >$1500/month; education >high school; employment; identifying as gay or bisexual; Indigenous status; injection drug use in last 6 months; injection drug use ever; past incarceration, and past psychiatric hospitalization. We fitted an item response theory model with: severity parameters (how likely an item was reported), discriminatory parameters, (how well a variable distinguished index levels), and an individual parameter (the index). We considered two models: a simple one with no provincial variation and a hierarchical model by province. The Widely Applicable Information Criterion (WAIC) was used to compare the fitted models. To showcase a potential utility of the proposed index, we evaluated with logistic regression the association of the index with non-attendance to a second clinic visit (as a proxy for disengagement) and using WAIC compared it to a model containing all the individual parameters that compose the index as covariates.
We analyzed 1547 complete cases of 1842 enrolled participants. According to the WAIC the hierarchical model provided a better fit when compared to the model that does not consider the individual's province. Values of the index were similarly distributed across the provinces. Overall, past incarceration, education, and unemployment had the highest discriminatory parameters. However, in each province different components of the index were associated with being deprived reflecting local epidemiology. For example, Saskatchewan had the highest severity parameter for Indigenous status while Quebec the lowest. For the secondary analysis, 457 (30%) failed to attend a second visit. A one-unit increase in the index was associated with 17% increased odds (95% credible interval, 2% to 34%) of not attending a second visit. The model with just the index performed better than the model with all the components as covariates in terms of WAIC.
We estimated an individual-level deprivation index in the Canadian Coinfection cohort. The index identified deprivation profiles across different provinces. This index and the methodology used may be useful in studying health and treatment outcomes that are influenced by social disparities in co-infected Canadians. The methodological approach described can be used in other studies with similar characteristics.
HIV-HCV 合并感染者通常比一般人群更贫困。然而，贫困程度难以衡量，往往依赖于无法捕捉个体异质性的总体数据。我们为 HIV-HCV 合并感染者开发了一个个体层面的贫困指数，其中包含了社会、物质和生活方式因素。
我们使用加拿大合并感染队列（一项全国性前瞻性队列研究）的数据来估计个体层面的贫困指数。我们使用预定的过程选择了基线访视时的 19 个二分变量中的 9 个纳入贫困模型：月收入>1500 加元；教育程度>高中；就业；自我认同为同性恋或双性恋；原住民身份；过去 6 个月使用注射毒品；过去使用过注射毒品；过去监禁和过去精神病住院治疗。我们使用项目反应理论模型拟合了以下参数：严重程度参数（报告某个项目的可能性）、区分参数（变量区分指数水平的能力）和个体参数（指数）。我们考虑了两种模型：一种是没有省级差异的简单模型，另一种是按省份分层的模型。广泛适用信息准则（WAIC）用于比较拟合模型。为了展示所提出指数的潜在实用性，我们使用逻辑回归评估了指数与第二次就诊（作为脱离接触的替代指标）的非就诊之间的关联，并使用 WAIC 将其与包含构成指数的所有个体参数作为协变量的模型进行了比较。
我们分析了 1842 名入组参与者中 1547 名完整案例。根据 WAIC，分层模型与不考虑个体省份的模型相比提供了更好的拟合。指数值在各省之间的分布相似。总体而言，过去监禁、教育和失业的区分参数最高。然而，在每个省份，指数的不同组成部分与贫困相关，反映了当地的流行病学情况。例如，萨斯喀彻温省原住民身份的严重程度参数最高，而魁北克省最低。对于二次分析，有 457 人（30%）未能参加第二次就诊。指数增加一个单位，与第二次就诊的可能性增加 17%（95%可信区间，2%至 34%）相关。仅指数模型在 WAIC 方面优于包含所有组成部分作为协变量的模型。
我们在加拿大合并感染队列中估计了一个个体层面的贫困指数。该指数确定了不同省份的贫困情况。这个指数和所使用的方法可能有助于研究受合并感染者社会差异影响的健康和治疗结果。所描述的方法学方法可用于具有类似特征的其他研究。
