Title |
Estimating Design Effect and Calculating Sample Size for Respondent-Driven Sampling Studies of Injection Drug Users in the United States
|
---|---|
Published in |
AIDS and Behavior, February 2012
|
DOI | 10.1007/s10461-012-0147-8 |
Pubmed ID | |
Authors |
Cyprian Wejnert, Huong Pham, Nevin Krishna, Binh Le, Elizabeth DiNenno |
Abstract |
Respondent-driven sampling (RDS) has become increasingly popular for sampling hidden populations, including injecting drug users (IDU). However, RDS data are unique and require specialized analysis techniques, many of which remain underdeveloped. RDS sample size estimation requires knowing design effect (DE), which can only be calculated post hoc. Few studies have analyzed RDS DE using real world empirical data. We analyze estimated DE from 43 samples of IDU collected using a standardized protocol. We find the previous recommendation that sample size be at least doubled, consistent with DE = 2, underestimates true DE and recommend researchers use DE = 4 as an alternate estimate when calculating sample size. A formula for calculating sample size for RDS studies among IDU is presented. Researchers faced with limited resources may wish to accept slightly higher standard errors to keep sample size requirements low. Our results highlight dangers of ignoring sampling design in analysis. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 3 | 75% |
Canada | 1 | 25% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 4 | 100% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
United Kingdom | 1 | <1% |
Chile | 1 | <1% |
United States | 1 | <1% |
Unknown | 148 | 98% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Researcher | 31 | 21% |
Student > Ph. D. Student | 21 | 14% |
Student > Master | 20 | 13% |
Student > Bachelor | 10 | 7% |
Student > Postgraduate | 8 | 5% |
Other | 24 | 16% |
Unknown | 37 | 25% |
Readers by discipline | Count | As % |
---|---|---|
Medicine and Dentistry | 36 | 24% |
Social Sciences | 23 | 15% |
Nursing and Health Professions | 15 | 10% |
Psychology | 7 | 5% |
Economics, Econometrics and Finance | 5 | 3% |
Other | 23 | 15% |
Unknown | 42 | 28% |