Unveiling disparities: examining differential item functioning's impact on racial health equity among white and black populations

E Villalonga-Olives; A Khademi; Y-Y Pan; Y Ransome

doi:10.1016/j.puhe.2024.03.006

Unveiling disparities: examining differential item functioning's impact on racial health equity among white and black populations

Public Health. 2024 Apr 17:231:80-87. doi: 10.1016/j.puhe.2024.03.006. Online ahead of print.

Authors

E Villalonga-Olives¹, A Khademi², Y-Y Pan², Y Ransome³

Affiliations

¹ Department of Practice, Sciences, and Health Outcomes Research, University of Maryland Baltimore, Baltimore, MD, USA. Electronic address: ester.villalonga@rx.umaryland.edu.
² Department of Practice, Sciences, and Health Outcomes Research, University of Maryland Baltimore, Baltimore, MD, USA.
³ Department of Social and Behavioral Sciences, Yale School of Public Health, USA.

PMID: 38636280
DOI: 10.1016/j.puhe.2024.03.006

Abstract

Objectives: This paper aims to examine the psychometric properties of social capital indicators, comparing Black and White respondents to identify the extent of measurement invariance in social capital by race.

Study design: We used data from the longitudinal study Midlife in the United States (MIDUS), waves 1 through 3 (1995-2016).

Methods: Data were from 6513 respondents (5604 White and 909 Black respondents). Social capital indicators were social cohesion, contributions to community, and community involvement. We used Structural Equation Modeling and Item Response Theory methods to test for measurement invariance in social capital by race.

Results: We observed violations of longitudinal and multi-group measurement invariance (MI) at configural and metric levels on two scales. Factor structures and indicator loadings were inconsistent over time. In IRT analysis, 'Many people come for advice' exhibited Differential Item Functioning (DIF), indicating a consistent advantage for White respondents on the contributions to community scale. Despite similar social capital levels (P(χ2,2) = 0.00), DIF was found in all contributions to community items and some community involvement items when examining race and education interaction.

Conclusions: Invariance issues in social capital items suggest potential biases in comparing Black and White respondents. Recognizing these biases is essential. Future social capital research should assess existing data assumptions and involve stakeholders from diverse communities in creating new items.

Keywords: Differencial item functioning; Health disparities; Item response theory; Measurement invariance; Racial differences; Social capital.