HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: AJPH.2007.111138v1 AJPH.2007.111138v2 99/8/1515    most recent Submit a response View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Odierna, D. H. Articles by Schmidt, L. A. PubMed PubMed Citation Articles by Odierna, D. H. Articles by Schmidt, L. A. Related Collections Epidemiology Socioeconomic Factors Surveys Other Statistics/Evaluation/Research Women's Health

Donna H. Odierna, DrPH, MS and Laura A. Schmidt, PhD, MSW, MPH

Donna H. Odierna is with the Philip R. Lee Institute for Health Policy Studies at the University of California, San Francisco. At the time of the study, she was a doctoral candidate at the University of California, Berkeley, and a predoctoral fellow at the Alcohol Research Group, Berkeley. Laura A. Schmidt is with the Philip R. Lee Institute for Health Policy Studies and the Department of Anthropology, History, and Social Medicine, School of Medicine, at the University of California, San Francisco.

Correspondence: Correspondence should be sent to Donna H. Odierna, Department of Clinical Pharmacy, University of California, San Francisco, 3333 California St, Suite 420, San Francisco, CA 94118 (e-mail: donna.odierna{at}ucsf.edu or dodierna{at}gmail.com). Reprints can be ordered at http://www.ajph.org by clicking on the "Reprints/Eprints" link.

Objectives. We sought to determine whether failure to locate hard-to-reach respondents in longitudinal studies causes biased and inaccurate study results.

Methods. We performed a nonresponse simulation in a survey of 498 low-income women who received cash aid in a California county. Our simulation was based on a previously published analysis that found that women without children who applied for General Assistance experienced more violence than did women with children who applied for Temporary Assistance to Needy Families. We compared hard-to-reach respondents whom we reinterviewed only after extended follow-up effort 12 months after baseline with other respondents. We then removed these hard-to-reach respondents from our analysis.

Results. Other than having a greater prevalence of substance dependence (14% vs 6%), there were no significant differences between hard- and easy-to-reach respondents. However, excluding the hard to reach would have decreased response rates from 89% to 71% and nullified the findings, a result that did not stem primarily from reduced statistical power.

Conclusions. The effects of failure to retain hard-to-reach respondents are not predicable based on respondent characteristics. Retention of these respondents should be a priority in public health research.