All studies on prevalence were conducted in the South and South-Eastern regions of Brazil, so we do not have data from other regions to compare. Even within the same region there is, however, an important variation on prevalence, but this is more likely due to differences in the methodology used in the different studies.

There are no estimates of prevalence of dementia by different geographical areas in Hong Kong.

As per the Global Burden of Disease (GBD) study (India State-Level Disease Burden Initiative Neurological Disorders Collaborators, 2021), 3.69 million people were living with Alzheimer’s disease and other dementias in 2019 in India. The GBD study (India State-Level Disease Burden Initiative Neurological Disorders Collaborators, 2021) also provides state-wise prevalence and crude DALY rate for Alzheimer’s disease and other dementias per 100,000 in 2019 (Table 6.3).

Table 6.3 depicts state wise prevalence and crude DALY rate (2019) – per 100,000

Source: (India State-Level Disease Burden Initiative Neurological Disorders Collaborators, 2021 (Data From Figure 2 and Supplementary Document)).

The numbers of persons with dementia are further estimated to increase by 197% between 2019-2050 in India, with 11.4 million people projected to live with dementia in India in 2050 (GBD 2019 Dementia Forecasting Collaborators, 2022).

References:

GBD 2019 Dementia Forecasting Collaborators. (2022). Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. The Lancet Public Health.

India State-Level Disease Burden Initiative Neurological Disorders Collaborators (2021). The burden of neurological disorders across the states of India: The Global Burden of Disease Study 1990-2019. The Lancet. Global health, 9(8), e1129–e1144.

There has been not enough evidence to conclude a dementia prevalence nationally. However, Surveymeter’s studies showed higher prevalence in rural areas both in Yogyakarta (23.0%) and Bali (36.1%) (Suriastini et al., 2016, 2018).

References:

Suriastini, Turana, Y., Sukadana, W., Sikoki, B., Witoelar, F., Lesmana, C. B. J., Mulyanto, E. D., Hermoko, R., & Anandari, G. A. A. A. (2018). Menggugah Lahirnya Kebijakan Kelanjutusiaan Menggugah Lahirnya Kebijakan Kelanjutusiaan.

Suriastini, Turana, Y., Witoelar, F., Supraptilah, B., Wicaksono, T., & Dwi, E. (2016). Policy Brief Angka Prevalensi Demensia: Perlu Perhatian Kita Semua. SurveyMETER, Maret, 1–4.

No data was found due to a paucity of data.

It is not evident through literature whether the prevalence of dementia is pronounced in some specific geographical areas. However, a report by the Africa Mental Health Research and Training Foundation revealed a high rate of people with mild to moderate cognitive impairment in Makueni County in Kenya. Among all people with mental health problems, the rate of cognitive impairment using Mini-Mental State Exam (MMSE) was estimated to be 16%. This led to dementia (manifested as cognitive impairment) being ranked third, after depression and drug and substance abuse (Mutiso et al., 2016). This is the only study in Kenya that has been conducted to estimate prevalent rates on dementia.

References:

Mutiso, V., Pike, K. M., Ndetei, D., Musau, A., Nandoya’, E., Musyimi’, C., … Wambua, R. (2016). Multi-sectoral Stakeholder TEAM Approach to Scale-Up Community Mental Health in Kenya: Building on Locally Generated Evidence and Lessons Learnt (TEAM). Nairobi, Kenya. https://www.mhinnovation.net/sites/default/files/downloads/innovation/reports/TEAM%20Project%20Report%20to%20County_Final_31_01_17.pdf

Even though there is no official data reported at the state level, an analysis with the data derived from ENSANUT (Acosta-Castillo et al., 2017) demonstrates great variability in the prevalence of dementia by state and suggests that numeorous people affected by dementia experience high levels of vulnerability.

References:

Acosta-Castillo, G. I., Sosa-Ortiz, A. L., Manrique Espinoza, B. S., Salinas Rodriguez, A., & Juárez, M. de los Á. L. (2017). Prevalence of Dementia By State and Level of Marginalization in Mexico. Alzheimer’s & Dementia, 13(7), P512. https://doi.org/10.1016/j.jalz.2017.06.583

There is no available data on the geographical spread of dementia in NZ. However, given the relationship between the risk factors for dementia and the social determinants of health, there is a possibility that the prevalence of dementia is higher in areas with greater deprivation. These risk factors also disproportionately affect Māori and Pacific people so in the regions where they comprise, a greater proportion of the population may also have an increased prevalence of dementia. For example, South Auckland is the most ethnically diverse region of NZ, with 38% of the population identifying as European or other, 24% as Asian, 21% as Pacific, and 16% as Māori (Counties Manukau District Health Board, 2015).

References:

Counties Manukau District Health Board. (2015). Counties Manukau Health. Population profile. CMDHB 2015.

There are limited data published with regards to the prevalence of dementia in Africa as well as South Africa (De Jager et al., 2017; Meyer et al., 2016). Although prevalence is generally expected to be higher in urban areas, a rural community study in Amatole District (Kwazulu-Natal) found a higher than expected prevalence rate of 11%, where the World Alzheimer’s report (2016) estimated 4% (De Jager et al., 2017). Modelled prevalence estimated from the Global Burden Disease Study (2017) indicates 167424,23 (0.32%) persons living with dementia in 2016 (Global Burden Disease Study, 2017a). Although no population-based dementia prevalence rates exist for the urban–rural geographical areas, national statistics indicate that the 65.1% of the country’s population over the age of 60 live in urban areas (StatsSA, 2015b). When disaggregated by population group, the dominance of the urban bias holds true for all population groups with the exception (although marginal) of the black African population, where most older persons (50.6%) for this group were found in rural areas in 2016 (StatsSA, 2015b).

References:

De Jager, C.A., Msemburi, W., Pepper, K., & Combrinck, M. (2017). Dementia Prevalence in a Rural Region of South Africa: A Cross-Sectional Community Study. Journal of Alzheimer’s Disease, 60(3), 1087–1096. https://doi.org/10.3233/JAD-170325

Global Burden Disease Study. (2017a). Global Burden Disease study: Results Tool (Prevalence). Available from: https://ghdx.healthdata.org/gbd-2017

Meyer, J. C., Harirari, P., & Schellack, N. (2016). Overview of Alzheimer ’ s disease and its management. South African Pharmaceutical Journal, 83(9), 48–56.

StatsSA. (2015b). Vulnerable Groups Series I: The Social Profile of Youth, 2009–2014. In StatsSA (Vol. 03, Issue 03). Available from:  http://www.statssa.gov.za/?p=6395%5Cnhttp://www.statssa.gov.za/?p=6135