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. 2012 Oct 16;1(2):13-21.
doi: 10.4236/sn.2012.12002.

Assessment of Random Recruitment Assumption in Respondent-Driven Sampling in Egocentric Network Data

Hongjie Liu  1 , Jianhua Li, Toan Ha, Jian Li
Affiliations

Assessment of Random Recruitment Assumption in Respondent-Driven Sampling in Egocentric Network Data

Hongjie Liu et al. Soc Netw. .

Abstract

Background: One of the key assumptions in respondent-driven sampling (RDS) analysis, called "random selection assumption," is that respondents randomly recruit their peers from their personal networks. The objective of this study was to verify this assumption in the empirical data of egocentric networks.

Methods: We conducted an egocentric network study among young drug users in China, in which RDS was used to recruit this hard-to-reach population. If the random recruitment assumption holds, the RDS-estimated population proportions should be similar to the actual population proportions. Following this logic, we first calculated the population proportions of five visible variables (gender, age, education, marital status, and drug use mode) among the total drug-use alters from which the RDS sample was drawn, and then estimated the RDS-adjusted population proportions and their 95% confidence intervals in the RDS sample. Theoretically, if the random recruitment assumption holds, the 95% confidence intervals estimated in the RDS sample should include the population proportions calculated in the total drug-use alters.

Results: The evaluation of the RDS sample indicated its success in reaching the convergence of RDS compositions and including a broad cross-section of the hidden population. Findings demonstrate that the random selection assumption holds for three group traits, but not for two others. Specifically, egos randomly recruited subjects in different age groups, marital status, or drug use modes from their network alters, but not in gender and education levels.

Conclusions: This study demonstrates the occurrence of non-random recruitment, indicating that the recruitment of subjects in this RDS study was not completely at random. Future studies are needed to assess the extent to which the population proportion estimates can be biased when the violation of the assumption occurs in some group traits in RDS samples.

Keywords: Egocentric Network; Random Selection Assumption; Respondent-Driven Sampling.

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Conflict of interest statement

Competing interests: The authors have no competing interests to declare. Authors’ contributions: HJL and JHL designed and participated in the study. HJL, TH and JL analyzed the data. HJL wrote the manuscript.

Figures

Figure 1
Figure 1
Recruitment of RDS seeds A-D (1 – 4 in Table 1).
See this image and copyright information in PMC

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