Carolien Zeetsen

39 CHAPTER Psychometric properties of the MoCA in healthy participants 2 Discussion The current study assessed the psychometric properties of the original version and two alternate versions of the MoCA in a group of healthy participants with an age range of 18–70 years. We found that older participants performed worse on MoCA–TS and –MIS than younger participants, while participants with higher educational levels and a higher estimated premorbid intelligence also obtained higher MoCA scores. Significant but small sex differences were found for MoCA–MIS, with women outperforming men. Systematic differences between versions were identified for the items animal naming, sentence repetition and MoCA–DS language and abstract reasoning. The test–retest reliability for the MoCA–TS was good (7.1–7.2) to excellent (7.1–7.3). For the MoCA–MIS, the test–retest reliability was poor (7.1–7.2) to fair (7.1–7.3). The current results show that performance on the MoCA is moderated by educational attainment, intelligence and age, and that these factors should be taken into account when interpreting results on this screener (Shulman, 2000). The effect of intelligence on MoCA performance was expected as it is known that intelligence typically correlates highly with level of education (Lezak et al., 2012), albeit that in older adults educational attainment and intelligence may not always correspond well because of limited access or possibilities to advanced schooling. Comparing our results of participants from a large age range with other studies shows they are in agreement with previous findings in adults aged 50 and older (Zheng et al., 2012; Sugarman et al., 2014; Malek–Ahmadi et al., 2015; Oren et al., 2015; Yancar Demir et al., 2015; Apolinario et al., 2018). Next, like several other studies, this study did not find an effect of sex on MoCA–TS (Zheng et al., 2012; Santangelo et al., 2015; Kopecek, Stepankova, et al., 2017; Apolinario et al., 2018). However, an effect of sex on the MoCA–MIS was found, in favour of women. Ojeda et al. (2016) also found an effect of sex on the delayed recall of the MoCA in Spanish participants aged ≥ 18. The difference between men and women in memory functioning has also been objectified in childhood ages (Gur et al., 2012) and in particular working memory tasks in adults (Saylik et al., 2018). No systematic differences between MoCA–TS of the alternate versions compared to version 7.1 were found, indicating that all versions are essentially equivalent. This was also found for the recently developed MoCA–MIS, replicating the findings of Chertkow et al. (2011) and Nasreddine et al. (2016) in older individuals. Taking a closer look at the items, however, it was found that animal naming, sentence repetition and abstract reasoning did systematically differ between versions, with some items of the alternate versions being more difficult and others less compared to MoCA version 7.1. Lebedeva et al. (2016) reported similar findings for both animal naming and abstract reasoning. They also found a performance difference for the item figure copy across the different versions. The fact that we did not