Epidemiology of Alzheimer’s Disease and Dementia in Arab Countries: A Systematic Review

Table 1

Studies of dementia prevalence.

Author	Year	Country	Study design	Criteria used for dementia identification	Cut-offs used for dementia diagnosis	Sample size	Setting/sampling tech	Study key findings
Farrag et al. [17]	1998	Egypt (Assiut governorate)	3-phase cross-sectionalpopulation-basedstudy	Modified MMSE; Clinical diagnosis; Lab investigations	Positive; Subjects scored 21 or less were eligible to proceed into phase 2 for clinical diagnosis; Negative; Scores 21 to 17 for mild; 16-9 for moderate; less than 9 for severe degrees of dementia	2000	Household; Systematic random of total elderly population age years (130,000 subjects)	CPR—4.5 cases per 100 population prevalence: AD—2.2; Multi-infarct dementia—0.95; Mixed dementia—0.55; Secondary dementias—0.45; Age-specific prevalence tends to double every 5 years after age of 75 years and above; The prevalence of dementia of all types for the age group: 60-64 years: 1.41 %; 65-69 years: 1.87 %; 70-74 years: 4.06%; 75-79 years: 6.46%; 80-84 years: 14.87%; 85 years or over: 22.01%
El Tallawy et al. [18]	2010	Egypt (Al Kharga district)	Cross-sectional	Short standardized Arabic screening test; MMSE	MMSE score: 21–17 for mild, 16–9 for moderate, and <9 for severe degree of dementia	8,173	Household; All residents (62,583 subjects) of whom 8,173 were of ≥50 years of age	Prevalence: >50 years—2.26%; >80—18.48%; Dementia subtypes: AD—51.2%; VaD—28.7%; Due to general medical conditions—12.8%; Due to multiple etiologies—7.3%; Degree of dementia according to; MMSE scores: Mild—53.7%; Moderate—38.4%; Severe—7.9%
El Tallawy et al.[19]	2014	Egypt (Al-Quseir city)	Cross-sectional	MMSE; Clinical exam investigations	A score of 17-21 for mild, 9-16 for moderate, and less than 9 for a severe degree of dementia	4,329	Household; All residents (33,285 subjects) of whom, 4,329 were of ≥50 years of age	Total—2.01%; Age: —.27%; —1.7%; —6.5%; >80—13.5%; Dementia subtypes: AD—48%; VaD—36%; Due to general medical condition—12%; Due to multiple etiologies—3%
Khedr et al. [20]	2015	Egypt	Cross-sectional	MES; MMSE; Neurological examination	MES total score 75–62 appear to be the range for patients with MCI; A score of 17–21 on MMSE for mild, 9–16 for moderate, and less than 9 for a severe degree of dementia	691	Household; Multistage random sampling	MCI—1.74 cases per 100 population; Dementia—5.07 cases/100 population; AD—1.74 cases/100 population; VaD—1.3 cases/100 population; Parkinson’s—1.01 cases/100 population
Chahine et al. [21]	2006	Lebanon	Cross-sectional	MMSE and GDS	Dementia diagnosed at; 25–29—nondemented but with indeterminate cognitive function; Mild, moderate, or severe dementia—20–24, 14–19, <14; Score of 30—normal cognitive function	117	Nursing home residents (NSR); Random	Dementia of some kind found in 61 NSR (59.8%); Mild dementia in 17 NSR (27.9%); Moderate dementia in 14 NSR (22.9%); Severe dementia in 30 NSR (49.2%); Depression in 45 NSR (57.7%)
Phung et al. [22]	2017	Lebanon	Cross-sectional	RUDAS	Scores ranging from 0 to 30; higher scores indicate better cognitive function	502	Household multistage cluster sampling	Crude dementia was less prevalent (7.4%) as compared to age-standardized dementia (9%). Based on estimated total number of Lebanese older than 65 years in 2013 (404,274 persons), the estimated number of people with dementia in Lebanon was 29,916 persons
Ghuloum et al. [23]	2011	Qatar	Cross-sectional	Designed screening questionnaire; Psychiatric assessment	—	1660 (297 were >50 yrs)	15 primary healthcare clinics; All 18-65 years old	Prevalence: Total—1.1% (M—1.8, F—.6), above 50 years
Ouanes et al. [24]	2014	Tunis	Cross-sectional	MoCA test	Scores on the MoCA range from zero to 30, with a score of 26 and higher generally considered normal	77	Manouba nursing home; All 116 residents; (mean )	Dementia—45(58.4%); Only three were already diagnosed
Ghubash et al. [25]	2004	United Arab Emirates (Dubai, Ras-Al-Khaimah, Al-Ain)	Cross-sectional	GMS-A3	—	610	Household, random sample of 843 households; (>60 yrs)	Cognitive impairment with or without dementia—3.6%

MMSE: modified mini-mental state examination; CPR: crude prevalence rate; MCI: mild cognitive impairment; VaD: vascular dementia; MES: Memory and Executive Screening test; GDS: Geriatric Depression Scale; NINCDS-ADRDA: National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association; NINDSAIREN: National Institute of Neurological Disorders and Stroke (NINDS) and the Association Internationale pour la Recherche et l’Enseignement en Neurosciences; SMQ: short-memory questionnaire; BCST: Brookdale Cognitive Screening Test; A-IQCODE 16: Arabic Version of 16-item Informant Questionnaire on Cognitive Decline for the older adults; DRG: Dementia Research Group; MoCA: Montreal Cognitive Assessment; GMS: Geriatric Mental State Interview; CERAD: Consortium to Establish a Registry of Alzheimer’s Disease; NEUROEX: physical assessment and brief neurological examination; RUDAS: Rowland Universal Dementia Assessment Scale.