{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T13:39:24Z","timestamp":1791380364863,"version":"4.3.3"},"reference-count":23,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100018734","name":"Joint United Nations Programme on HIV\/AIDS","doi-asserted-by":"publisher","award":["7200GH22IO00004"],"award-info":[{"award-number":["7200GH22IO00004"]}],"id":[{"id":"10.13039\/501100018734","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000780","name":"European Commission","doi-asserted-by":"publisher","award":["20101211"],"award-info":[{"award-number":["20101211"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Both snowball sampling and Respondent Driven Sampling (RDS) are used to sample hard-to-reach populations. Snowball sampling was initially developed as a probability sampling method, but in practice, it is widely used as a non-probabilistic sampling method. RDS was developed to address the limitations of snowball sampling and can be used to approximate a probability sampling method in practice. Therefore, RDS is often recommended for bio-behavioral surveys (BBS) for surveillance of HIV, viral hepatitis, and STIs among key populations. In some settings, simpler and cheaper monitoring are desired. WHO and UNAIDS are developing a simplified and rapid bio-behavioral survey methodology, a version of snowball sampling to use when RDS is infeasible. In this paper, we use data-based simulations to examine the potential similarities and differences between results from a snowball sample with recruitment initiated from a health service and samples recruited through RDS methodology.<\/jats:p>","DOI":"10.1371\/journal.pone.0331666","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T18:35:41Z","timestamp":1768415741000},"page":"e0331666","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":6,"title":["Comparing snowball sampling and RDS: A methodology and case study"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4638-7514","authenticated-orcid":true,"given":"Dongah","family":"Kim","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krista J.","family":"Gile","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bradley","family":"Mathers","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Massimo","family":"Mirandola","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lorenzo","family":"Gios","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Igor","family":"Toskin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keith M.","family":"Sabin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"issue":"1","key":"pone.0331666.ref001","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1214\/aoms\/1177705148","article-title":"Snowball sampling","volume":"32","author":"LA Goodman","year":"1961","journal-title":"Ann Math Statist."},{"issue":"4","key":"pone.0331666.ref002","doi-asserted-by":"crossref","first-page":"28","DOI":"10.17730\/humo.17.4.q5604m676260q8n7","article-title":"Relational analysis: the study of social organizations with survey methods","volume":"17","author":"JS Coleman","year":"1958","journal-title":"Human Organization."},{"issue":"2","key":"pone.0331666.ref003","doi-asserted-by":"crossref","first-page":"174","DOI":"10.2307\/3096941","article-title":"Respondent-driven sampling: a new approach to the study of hidden populations","volume":"44","author":"DD Heckathorn","year":"1997","journal-title":"Social Problems."},{"issue":"1","key":"pone.0331666.ref004","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1525\/sp.2002.49.1.11","article-title":"Respondent-driven sampling II: deriving valid population estimates from chain-referral samples of hidden populations","volume":"49","author":"DD Heckathorn","year":"2002","journal-title":"Social Problems."},{"key":"pone.0331666.ref005","doi-asserted-by":"crossref","DOI":"10.1007\/s10461-008-9421-1","article-title":"Using respondent-driven sampling methodology for HIV biological and behavioral surveillance in international settings: a systematic review","volume":"12","author":"M Malekinejad","year":"2008","journal-title":"AIDS Behav."},{"issue":"1","key":"pone.0331666.ref006","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1177\/075910639203700102","article-title":"Generalization and statistical inference from snowball samples","volume":"37","author":"WD TenHouten","year":"1992","journal-title":"Bulletin of Sociological Methodology\/Bulletin de M\u00e9thodologie Sociologique."},{"issue":"1","key":"pone.0331666.ref007","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1177\/075910639203600104","article-title":"Estimation on the basis of snowball samples: how to weight?","volume":"36","author":"TAB Snijders","year":"1992","journal-title":"Bulletin of Sociological Methodology\/Bulletin de M\u00e9thodologie Sociologique."},{"key":"pone.0331666.ref008","unstructured":"Frank O. 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