Am J Epidemiol. 2020 Oct 1;189(10):1185-1196. doi: 10.1093/aje/kwaa070.
Accurate survival estimates are needed for guiding cancer control efforts in sub-Saharan Africa, but previous studies have been hampered by unknown biases due to excessive loss to follow-up (LTFU). In the African Breast Cancer-Disparities in Outcomes Study, a prospective breast cancer cohort study, we implemented active mobile health follow-up, telephoning each woman or her next-of-kin (NOK) trimonthly on her mobile phone to update information on her vital status. Dates of every contact with women/NOK were analyzed from diagnosis in 2014-2017 to the earliest of September 1, 2018, death, or 3 years postdiagnosis. The cumulative incidence of being LTFU was calculated considering deaths as competing events. In all, 1,490 women were followed for a median of 24.2 (interquartile range (IQR), 14.2-34.5) months, corresponding to 8,529 successful contacts (77% of total contacts) with the women/NOK. Median time between successful contacts was 3.0 (IQR, 3.0-3.7) months. In all, 71 women (5.3%) were LTFU at 3 years: 0.8% in Nigeria, 2.2% in Namibia, and 5.6% in Uganda. Because of temporary discontinuity of active follow-up, 20.3% of women were LTFU after 2 years in Zambia. The median time to study notification of a death was 9.1 (IQR, 3.9-14.0) weeks. Although the present study was not a randomized controlled trial, in this cancer cohort with active mobile health follow-up, LTFU was much lower than in previous studies and enabled estimation of up-to-date and reliable cancer survival.
准确的生存估计对于指导撒哈拉以南非洲的癌症控制工作至关重要，但由于失访（LTFU）率过高导致未知偏倚，之前的研究受到了阻碍。在非洲乳腺癌-结局差异研究中，我们开展了一项前瞻性乳腺癌队列研究，通过移动健康随访积极跟踪患者，每三个月通过患者的移动电话致电每位女性或其近亲（NOK），更新其生命体征信息。从 2014 年至 2017 年诊断开始至 2018 年 9 月 1 日最早死亡或诊断后 3 年的时间内，分析了每位女性/NOK 的每次接触日期。考虑到死亡是竞争事件，计算 LTFU 的累积发生率。共有 1490 名女性接受了中位时间为 24.2 个月（四分位距（IQR），14.2-34.5）的随访，共成功联系了 8529 次女性/NOK（占总联系次数的 77%）。成功联系之间的中位数时间为 3.0 个月（IQR，3.0-3.7）。在所有女性中，共有 71 名（5.3%）在 3 年内失访：尼日利亚为 0.8%，纳米比亚为 2.2%，乌干达为 5.6%。由于主动随访的暂时中断，赞比亚有 20.3%的女性在 2 年后失访。研究通知死亡的中位时间为 9.1 周（IQR，3.9-14.0）。尽管本研究不是随机对照试验，但在这项接受主动移动健康随访的癌症队列研究中，LTFU 远低于之前的研究，能够估计最新和可靠的癌症生存情况。
