This repository includes the analyses of the polytomous survey items developed for identifying psycho-social factors that could affect liver disease progression among patients with chronic hepatitis B infection (CHB). The goal was to examine the psychometric properties and the factor structures of the five scales from the questionnaire based on IRT and factor-analytic approaches.

Models and brief summary of findings

• A graded response model (GRM) was used to investigate the psychometric properties of the items, except for two items from the hepatitis B stigma scale.
• Measurement invariance was assessed using the GRM, and the results showed pronounced differential item functioning (DIF) among people with different native languages (Korean vs. English) in terms of acculturative stress and COVID-19.
• CFA: No strong evidence was found to support the theory-based factor structures in the four scales: Acculturative stress, General health, Depression, CHB related stigma
• EFA: Only unstable solutions were produced calling for the need of future analyses with greater sample size.