Differentiated care delivery aims to simplify care of people living with HIV, reflect their preferences, reduce burdens on the healthcare system, maintain care quality and preserve resources. However, assessing program effectiveness using observational data is difficult due to confounding by indication and randomized trials may be infeasible. Also, benefits can reach patients directly, through enrollment in the program, and indirectly, by increasing quality of and accessibility to care. Low-risk express care (LREC), the program under evaluation, is a nurse-centered model which assigns patients stable on ART to a nurse every two months and a clinician every third visit, reducing annual clinician visits by two thirds. Study population is comprised of 16,832 subjects from 15 clinics in Kenya. We focus on patient retention in care based on whether the LREC program is available at a clinic and whether the patient is enrolled in LREC. We use G-estimation to assess the effect on retention of two “strategies”: (i) program availability but no enrollment; (ii) enrollment at an available program; versus no program availability. Compared to no availability, LREC results in a non-significant increase in patient retention, among patients not enrolled in the program (indirect effect), while enrollment in LREC is associated with a significant extension of the time retained in care (direct effect). G-estimation provides an analytical framework useful to the assessment of similar programs using observational data.

中文翻译：

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评估撒哈拉以南非洲地区差异化护理计划中 HIV 感染者的保留情况：G 估计方法

差异化护理服务旨在简化对艾滋病毒感染者的护理，反映他们的偏好，减轻医疗保健系统的负担，保持护理质量并保护资源。然而，由于适应症的混杂，使用观察数据评估项目有效性很困难，而且随机试验可能不可行。此外，患者可以通过加入该计划直接受益，也可以通过提高护理质量和可及性间接受益。正在评估的项目低风险快速护理 (LREC) 是一种以护士为中心的模式，每两个月将接受 ART 治疗稳定的患者分配给一名护士，每三次就诊一名临床医生，从而将临床医生每年的就诊次数减少三分之二。研究人群由来自肯尼亚 15 个诊所的 16,832 名受试者组成。我们根据诊所是否提供 LREC 计划以及患者是否参加了 LREC 来关注患者的护理保留率。我们使用 G 估计来评估两种“策略”对保留的影响：（i）项目可用性但不注册；(ii) 注册现有课程；与没有程序可用性。与没有可用性相比，LREC 导致未参加该计划的患者的患者保留率没有显着增加（间接影响），而参加 LREC 则与护理时间的显着延长相关（直接影响）。G 估计提供了一个分析框架，可用于使用观测数据评估类似项目。