Evaluating Differential Item Functioning of the PRIME-MD Mood Module Among Impoverished Black and White Women in Primary Care
Received 8 February 2007; accepted 2 October 2007. published online 10 December 2007.
Background
Appropriate treatment of depression requires accurate screening and diagnosis. It is important to evaluate depression screening instruments for differential item functioning (DIF) across diverse populations. The PRIME-MD is commonly used in primary care settings to screen for the most common psychiatric disorders, including depression. The purpose of this study was to determine whether items in the mood module of the PRIME-MD perform similarly in 2 high-risk populations: impoverished black and white women.
Methods
Data were collected during screening for a randomized controlled trial of treatment for depression in women receiving county health and welfare services. Analyses are based on a sample of 3,506 black (n = 3,191) and white (n = 315) women who completed the PRIME-MD mood module. Responses were compared using an item response theory approach to DIF assessment. Mean scores, missing data, and internal consistency reliability were also compared.
Results
None of the 9 items exhibited significant DIF. Missing data rates and internal consistency reliability did not differ for the 2 groups. Mean comparisons indicated that white women endorsed higher levels of depression compared with black women on 6 of the 9 items (p < .05).
Conclusions
These results suggest that all items of the mood module of the PRIME-MD performed similarly for white and black women. Differences in endorsed depressive symptomatology on the mood module may be attributed to actual differences in DSM-IV depression symptoms between white and black women.
bUCLA Department of Medicine/Division of General Internal Medicine and Health Services Research, Los Angeles, California
cUCLA/NPI Health Services Research Center, Los Angeles, California
Correspondence to: Kimberly A. Hepner, PhD, RAND Corporation, 1776 Main Street, PO Box 2138, Santa Monica, CA 90407-2138; Phone: 310-393-0411; fax: 310-393-4818.
Supported by the UCLA/DREW Project EXPORT, National Institutes of Health, National Center on Minority Health & Health Disparities, (P20-MD00148-01). Supported in part by UCLA Center for Health Improvement in Minority Elders/Resource Centers for Minority Aging Research, National Institutes of Health, National Institute of Aging (AG-02-004; to R.D.H. and L.M.).
1 Kimberly A. Hepner, PhD, is an Associate Behavioral Scientist at the RAND Corporation in Santa Monica, CA. She is a clinical psychologist whose current research focuses on quality of care for depression in both primary care and mental health specialty settings, with an emphasis on improving measurement of both processes and outcomes of depression care.
2 Leo S. Morales, MD, PhD, is Associate Professor in the Division of General Internal Medicine and Health Services Research, Geffen School of Medicine at UCLA and an affiliated researcher at RAND. He is co-Director of the UCLA Resource Center for Minority Aging Research. His research interests include minority health, disparities in health care and psychometrics.
3 Ron D. Hays, PhD, is Professor of Medicine in the Department of Health Services and the Division of General Internal Medicine and Health Services Research in the Department of Medicine, UCLA School of Medicine. He is also a Senior Health Scientist at RAND. His research interests include the development of research instruments to assess patient evaluations of health care, health-related quality of life, and other health outcomes.
4 Maria Orlando Edelen, PhD, is now an Assistant Professor (research) and Director of Quantitative Sciences at Brown University Medical School Department of Psychiatry and Human Behavior in Providence, RI. She is a psychometrician with current interests in measurement of mental health and substance use.
5 Jeanne Miranda, PhD, is a Professor in the Department of Psychiatry and Biobehavioral Sciences at UCLA. She is a clinical psychologist who has focused her work on providing mental health care to low-income and minority communities.
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