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Sampling challenges in a study examining refugee resettlement

Cheryl MR Sulaiman-Hill* and Sandra C Thompson

BMC International Health and Human Rights 2011, 11:2  doi:10.1186/1472-698X-11-2

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Snowball is not the only method for sampling refugees and similar populations

Keith Sabin   (2011-05-23 16:14)  WHO email

We commend Sulaiman-Hill and Thompson for their use of a mixed methods approach to research the resettlement experiences of Afghan and Kurdish refugees in New Zealand and Western Australia. However, we disagree with the authors’ presentation of snowball sampling as the “only feasible way of locating” hidden populations that do not have sampling frames. While we agree that “obtaining statistically representative samples of such socially invisible groups is known to be problematic,” we would like to point out that there are probability-based sampling methods that can be used to generate valid population-based estimates among hidden populations. Time-location sampling (TLS) and respondent driven sampling (RDS) have been used worldwide since 1994 for research among "hidden" populations, such as sex workers, men who have sex with men, injection drug users, artists, high-risk youth, migrants, and other populations that form social networks [1-4].

The success of snowball sampling in the Afghan and Kurdish refugee populations suggests that RDS is a feasible probability-based sampling method in this population. RDS is a chain-referral sampling method whereby peers recruit other peers from within their social networks. Features, such as enforcement of recruitment quotas through the use of uniquely coded coupons and analytical adjustments based on differential recruitment (homophily) and social network sizes, allow RDS to overcome many of the biases found in other chain-referral methods [5-6].

The feasibility of RDS in migrant and refugee populations is due to the key role of social networks in the migration and settlement process [7]. While RDS has not specifically been used to recruit Middle Eastern refugees in western settings, it has been used to recruit diverse migrant populations, such as Polish immigrants in Ireland [8]; rural-to-urban migrants in China [9]; and Southeast Asian [10] and Latino immigrants in the United States [11,12]. Additionally, it is being proposed as a primary sampling method to access migrant workers in South and Southeast Asia [13]. While these populations may not be culturally similar to Afghan and Kurdish refugees in New Zealand and Western Australia, they do share similar social circumstances that present comparable methodological challenges to researchers and would be suitable for sampling via RDS.

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Authors: Jane R Montealegre, Lisa G Johnston, Keith Sabin

Jane R Montealegre, The University of Texas School of Public Health, USA
Lisa G Johnston, University of California, San Francisco, Global Health Science, USA
Keith Sabin, World Health Organization, Hanoi, Vietnam

Competing interests

We have no competing interests


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