Lincoln International Institute for Rural Health, University of Lincoln, Brayford Pool, Lincoln, Lincolnshire, LN6 7TS, UK.
Centre Population et Développement (UMR 196 Paris Descartes - IRD), SageSud (ERL INSERM 1244), Institut de Recherche pour le Développement, Paris, France.
BMC Med Res Methodol. 2021 Feb 5;21(1):25. doi: 10.1186/s12874-021-01208-x.
Many respondent-driven sampling (RDS) methodologies have been employed to investigate hard-to-reach populations; however, these methodologies present some limits. We describe a minimally investigated RDS methodology in which peer recruitment and interviewing are phone-based. The feasibility of the methodology, field experiences, validity of RDS assumptions and characteristics of the sample obtained are discussed.
We conducted a phone-based RDS survey among men who have sex with men (MSM) aged 18 or above and living in Côte d'Ivoire. Eight initial MSM across Côte d'Ivoire were selected. Participants were asked to call a hotline to be registered and interviewed by phone. After the participants completed the questionnaire, they were asked to recruit a maximum of 3 MSM from their acquaintances.
During the 9 months of the survey, 576 individuals called the hotline, and 518 MSM completed the questionnaire. The median delay between the invitation to participate and the completion of the questionnaire by peer-recruited MSM was 4 days [IQR: 1-12]. The recruitment process was not constant, with high variation in the number of people who called the hotline during the survey period. RDS chain convergence to equilibrium was reached within 6 waves for most of the selected variables. For the network size estimation assumption, participants who incorrectly estimated their network size were observed. Regarding the sample obtained, MSM were recruited from all the regions of Côte d'Ivoire with frequent interregional recruitment; 23.5% of MSM were recruited by someone who does not live in the same region. Compared to the MSM who participated in two other surveys in Côte d'Ivoire, the MSM in our sample were less likely to know about an MSM non-governmental organisation. However, MSM aged 30 years old and above and those with a low level of education were underrepresented in our sample.
We show that phone-based RDS surveys among MSM are feasible in the context of sub-Saharan Africa. Compared to other classical RDS survey methodologies, the phone-based RDS methodology seems to reduce selection bias based on geography and proximity with the MSM community. However, similar to other methodologies, phone-based RDS fails to reach older and less-educated MSM.
许多回应驱动抽样（RDS）方法已被用于调查难以接触的人群；然而，这些方法存在一些局限性。我们描述了一种研究甚少的 RDS 方法，其中同伴招募和访谈是基于电话的。讨论了该方法的可行性、现场经验、RDS 假设的有效性以及获得的样本特征。
我们在科特迪瓦进行了一项基于电话的 RDS 调查，调查对象为年龄在 18 岁及以上的男男性行为者（MSM）。科特迪瓦各地选择了 8 名初始 MSM。参与者被要求拨打热线电话进行注册，并通过电话接受访谈。参与者完成问卷后，他们被要求从熟人中最多招募 3 名 MSM。
在调查的 9 个月中，有 576 人拨打了热线电话，有 518 名 MSM 完成了问卷。由同伴招募的 MSM 从受邀参加调查到完成问卷的中位时间延迟为 4 天[IQR：1-12]。招募过程并不稳定，在调查期间拨打热线电话的人数变化很大。对于大多数选定的变量，RDS 链收敛到平衡的时间在 6 波之内。对于网络规模估计假设，观察到参与者错误估计其网络规模的情况。关于获得的样本，MSM 是从科特迪瓦的所有地区招募的，经常在地区之间进行招募；23.5%的 MSM 是由居住在同一地区以外的人招募的。与在科特迪瓦参加的另外两项调查中的 MSM 相比，我们样本中的 MSM 不太可能知道男男性行为者非政府组织。然而，我们的样本中年龄在 30 岁及以上和受教育程度较低的 MSM 代表性不足。
我们表明，在撒哈拉以南非洲地区，基于电话的 MSM RDS 调查是可行的。与其他经典 RDS 调查方法相比，基于电话的 RDS 方法似乎减少了基于地理位置和与 MSM 社区接近程度的选择偏差。然而，与其他方法一样，基于电话的 RDS 无法接触到年龄较大和受教育程度较低的 MSM。
