Migrant Health Inequalities or Unequal Measurements? Testing for Cross-cultural and Longitudinal Measurement Invariance of Subjective Physical and Mental Health

Abstract

Background: The aim of the study is to investigate the longitudinal and cross-cultural measurement invariance of the Short-Form 12-Item Health Survey (SF-12) between Native Germans, European migrants and Non-European Migrants. Further, we test for differences in latent means dependent on invariance restrictions. Methods: We include 7 waves (2006-2018) from a representative panel study in Germany. We apply Multigroup Confirmatory Factor Analysis via a Structural Equation Modelling approach. Finally, we compare gender and age adjusted latent means between different settings of invariance assumptions. Results: The decrease in model fit measures by increasing equality constraints on the SF-12 factor structure of both physical and mental health between origin groups and across time is within common thresholds for good model fit. Latent means of both health factors differ, dependent on whether scalar invariance is set longitudinally and cross-culturally, or only longitudinally. Conclusion: We conclude acceptable longitudinal and cross-cultural measurement invariance of the SF-12 for a period of 12 years. Yet, ignoring multigroup scalar invariance constraints produces bias in the latent means of both health factors, where migrant health is shown to be overestimated, especially for Non-European migrants if indicator intercepts are not sufficiently constrained.