Measurement Invariance of the Pediatric Version of PROMIS Symptom Scales between American and Chinese Children with Cancer

This study assesses measurement invariance of the symptom scales (i.e., anxiety, depression fatigue, and pain) of the pediatric version of Patient Reported Outcomes Measurement Information System (PROMIS) between American and Chinese children with cancer. First, we used categorical confirmatory factor analysis (CCFA) to test the factorial structures of the four PROMIS symptom scales for the American and Chinese populations, respectively. Once we have confirmed that the symptom scales have similar factorial structure in both populations, multi-group CCFA models were used to test measurement invariance of the scales across the populations. The Top-down approach was applied for implementing measurement invariance assessment. Our results show that the four PROMIS symptom scales have adequate structural validity in both American and China populations of children with cancer. Though the full measurement invariance models have acceptable model fit indices, non-invariance was identified in a few factor loadings and item thresholds in the four PROMIS symptom scales across cultures. The non-invariant factor loadings indicate a lower reliability of these items in Chinese population compared to the American population. The non-invariant thresholds indicates that the Chinese patients were less likely to endorse the “Often” and “Always” categories of the corresponding items, holding the level of the latent construct constant. Further studies are needed to gauge the PROMIS items that show non-invariant factor loadings and/or item thresholds across cultures.