Supplementary Material for: Culturally Adapted Cognitive Screening: Validation of the Jilla Moroccan Dementia Scale

Background:
Standard cognitive screening instruments such as the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) often fail to identify cognitive impairment in individuals with low literacy or no formal education, as these tests rely heavily on reading, writing, and abstract reasoning. In Morocco and other low- and middle-income countries (LMICs), this limitation contributes to the under-recognition and diagnostic inaccuracy of dementia, particularly in communities with limited access to education or healthcare resources.
Objective:
To develop and validate a culturally adapted, literacy-independent cognitive screening battery, the Jilla Moroccan Dementia Scale (J-MDS), specifically designed for use among adults with limited schooling in Morocco.
Methods:
The J-MDS comprises 17 entirely oral and pictorial subtests assessing memory, attention, language, executive function, praxis, and orientation. A total of 109 participants were included (54 living with dementia and 55 cognitively healthy controls). Dementia diagnosis was established according to DSM-5 clinical criteria, which served as the gold standard. Psychometric properties of the J-MDS were compared with the Moroccan Arabic version of the MoCA (MoCA-Darija). Internal consistency, concurrent validity, and diagnostic accuracy were assessed following the STARDem guidelines.
Results:
The J-MDS demonstrated excellent internal consistency (Cronbach’s α = 0.936) and a strong correlation with the MoCA (ρ = 0.944, p < 0.001). Receiver Operating Characteristic (ROC) analysis showed an Area Under the Curve (AUC) of 0.986, with an optimal cut-off score of 82, yielding 98.15 % sensitivity and 94.55 % specificity for dementia detection. Test performance was unaffected by gender, moderately influenced by age and education level, and remained robust across literacy groups.
Conclusion:
The J-MDS is a reliable, culturally relevant, and clinically feasible cognitive screening tool for low-literacy populations. Its strong psychometric performance and simple administration make it well suited for community and primary care settings in Morocco and comparable LMICs. Future multicentre and longitudinal studies are recommended to establish normative data and confirm its applicability across diverse cultural contexts.