Sampling by Professional Referral: Lessons Learned From AskingPhysicians to Recruit Patients in Two Health Surveys
Hogan, S. O., Power, M., Schulkin, J., & Loft, J. D. (2010, May). Sampling by Professional Referral: Lessons Learned From Asking Physicians to Recruit Patients in Two Health Surveys. Presented at AAPOR 2010, .
Convenience sampling may be a practical alternative for conducting research when no frame is available for probability sampling. Examples might include samples of people with rare diseases, persons recovering from compulsive behaviors, or those involved in some stigmatized activity. When there is no reliable list from which to draw a statistical sample, one alternative is to rely on sampling by referrals, sometimes called snowball sampling (Welch, 1975;), respondent-driven sampling (Heckathorn 2002), or multiplicity sampling (Rothbart, Fine & Sudman, 1982).
Referral sampling usually involves identifying individuals who meet inclusion criteria, gaining their cooperation, and then asking them to recruit additional respondents with the same conditions (Heckathorn, 2002). Professional referral sampling has received less notice as a methodology, but is used in health and mental health research. Professional referral sampling involves selecting respondents through an intermediary who provides professional services to the subject. Intermediaries might include pediatricians (Stille et al. 2007), school nurses (Lee et al. 2009), or substance abuse clinicians (Fals-Stewart, Birchler and Kelley 2006).
We compare our experiences conducting two surveys depending on professional referral sampling. In each case, physicians acted as intermediaries, helping identify subjects with specific health conditions. Several related lessons learned are reported and presented for further hypothesis testing.