Geo‐Cultural Influence on Change in CDR and MMSE Scores

Abstract

AbstractBackgroundAlzheimer’s disease (AD) clinical trials are increasingly global. Most measures used were validated and standardized with North American, White, English‐speaking populations with limited consideration of cultural nuance. Prior research suggests that both the Clinical Dementia Rating (CDR) and Mini Mental State Examination (MMSE) are not free from cultural and linguistic influence. It is important to understand how geo‐cultural factors influence longitudinal change in scores on these measures, which is often used as the primary endpoint for study efficacy. In this study, we examined whether change in CDR and MMSE scores over one‐year follow‐up varied across geo‐cultural regions.MethodThis study included electronic CDR (eCDR) and electronic MMSE (eMMSE) data from four multi‐national AD clinical trials of subjects with prodromal to mild AD. Data were collected at screening and one‐year follow‐up from seven geo‐cultural regions: East Asia (n = 138); Eastern Europe (n = 170); Western Europe (n = 484); North America (n = 496); South America (n = 55); Middle East/Africa (n = 26); and Oceania (n = 26).ResultThe Kruskal–Wallis test found statistically significant variance in CDR‐Sum of Box (CDR‐SB) scores across geo‐cultural regions (p <0.0001). Results of the Dunn’s test indicated mean change in CDR‐SB scores for South America was significantly lower than those for North America, Eastern Europe, Western Europe, and Mideast/Africa. Additionally, mean change in CDR‐SB scores for East Asia was significantly lower than those for Western and Eastern Europe. Change in MMSE total scores did not vary across geo‐cultural regions.ConclusionOur study found average change in CDR‐SB but not MMSE total scores differed significantly across geo‐cultural regions. CDR‐SB scores were relatively more stable in South America compared to most other regions, and in East Asia compared to Western/Eastern Europe. The CDR may be more susceptible to cultural factors due to its reliance on subjective information from caregivers, in contrast with the MMSE, a standardized, objective measure. Different social norms and expectations for aging, functional independence, and trial participation in these regions may have contributed to the variance. Future studies should examine if specific CDR or MMSE items are more contextually dependent on the local culture.