Department of Epidemiology, University of Washington, Seattle, Washington, United States of America.
PLoS One. 2012;7(8):e43138. doi: 10.1371/journal.pone.0043138. Epub 2012 Aug 21.
Longitudinal studies of HIV-1-infected individuals or those at risk of infection are subject to missed study visits that may have negative consequences on the care of participants and can jeopardize study validity due to bias and loss of statistical power. Distance between participant residence and study clinic, as well as other socioeconomic and demographic factors, may contribute to interruptions in patient follow-up.
HIV-1-serodiscordant couples were enrolled between May 2007 and October 2009 and followed for two years in Nairobi, Kenya. At baseline, demographic and home location information was collected and linear distance from each participant's home to the study clinic was determined. Participants were asked to return to the study clinic for quarterly visits, with follow-up interruptions (FUI) defined as missing two consecutive visits. Cox proportional hazards regression was used to assess crude and adjusted associations between FUI and home-to-clinic distance, and other baseline characteristics.
Of 469 enrolled couples, 64% had a female HIV-1-infected partner. Overall incidence of FUI was 13.4 per 100 person-years (PY), with lower incidence of FUI in HIV-1-infected (10.8 per 100 PY) versus -uninfected individuals (16.1 per 100 PY) (hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.50, 0.88). Among HIV-1-infected participants, those living between 5 and 10 kilometers (km) from the study clinic had a two-fold increased rate of FUI compared to those living <5 km away (HR = 2.17; 95% CI: 1.09, 4.34). Other factors associated with FUI included paying higher rent (HR = 1.67; 95% CI: 1.05, 2.65), having at least primary school education (HR = 1.96; 95% CI: 1.02, 3.70), and increased HIV-1 viral load (HR = 1.23 per log(10) increase; 95% CI: 1.01, 1.51).
Home-to-clinic distance, indicators of socioeconomic status, and markers of disease progression may affect compliance with study follow-up schedules. Retention strategies should focus on participants at greatest risk of FUI to ensure study validity.
对 HIV-1 感染者或有感染风险的个体进行纵向研究可能会错过研究访问，这可能对参与者的护理产生负面影响，并由于偏倚和统计效力的损失而危及研究的有效性。参与者居住地与研究诊所之间的距离，以及其他社会经济和人口统计学因素，可能会导致患者随访中断。
HIV-1 血清学不一致的夫妇于 2007 年 5 月至 2009 年 10 月在肯尼亚内罗毕入组，并在两年内接受随访。在基线时，收集了人口统计学和家庭位置信息，并确定了每个参与者家庭到研究诊所的直线距离。要求参与者每季度返回研究诊所进行就诊，错过两次连续就诊定义为就诊中断（FUI）。使用 Cox 比例风险回归评估 FUI 与家庭到诊所距离以及其他基线特征之间的粗关联和调整关联。
在入组的 469 对夫妇中，64%的女性 HIV-1 感染者的伴侣。FUI 的总发生率为每 100 人年 13.4 例（100PY），HIV-1 感染者的 FUI 发生率（每 100PY10.8 例）低于未感染者（每 100PY16.1 例）（风险比 [HR] = 0.66；95%置信区间 [CI]：0.50，0.88）。在 HIV-1 感染者中，与居住在距离诊所<5 公里的参与者相比，居住在距离诊所 5 至 10 公里之间的参与者的 FUI 发生率增加了一倍（HR = 2.17；95%CI：1.09，4.34）。与 FUI 相关的其他因素包括支付更高的租金（HR = 1.67；95%CI：1.05，2.65）、至少接受过小学教育（HR = 1.96；95%CI：1.02，3.70）和 HIV-1 病毒载量增加（HR = 每增加 1 对数（10）增加 1.23；95%CI：1.01，1.51）。
家庭到诊所的距离、社会经济地位指标和疾病进展标志物可能会影响对研究随访计划的遵守情况。保留策略应侧重于最有可能发生 FUI 的参与者，以确保研究的有效性。
