Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-26T21:15:20.015Z Has data issue: false hasContentIssue false
  • English
  • Français

A longitudinal study of cognitive decline in rural Tanzania: rates and potentially modifiable risk factors

Published online by Cambridge University Press:  21 March 2018

Jessica Heward ,
Lydia Stone ,
Stella-Maria Paddick ,
Sarah Mkenda ,
William K. Gray ,
Catherine L. Dotchin ,
John Kissima ,
Cecilia Collingwood ,
Bernadetha Swai  and
Richard W. Walker
Jessica Heward
Affiliation:
The Medical School, Newcastle University, Newcastle upon Tyne, UK
Lydia Stone
Affiliation:
The Medical School, Newcastle University, Newcastle upon Tyne, UK
Stella-Maria Paddick
Affiliation:
Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, UK Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
Sarah Mkenda
Affiliation:
Kilimanjaro Christian Medical University College, Moshi, Tanzania
William K. Gray
Affiliation:
Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, UK
Catherine L. Dotchin
Affiliation:
Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, UK Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
John Kissima
Affiliation:
Hai District Medical Centre, Boman'gombe, Kilimanjaro Region, Tanzania
Cecilia Collingwood
Affiliation:
The Medical School, Newcastle University, Newcastle upon Tyne, UK
Bernadetha Swai
Affiliation:
Hai District Medical Centre, Boman'gombe, Kilimanjaro Region, Tanzania
Richard W. Walker*
Affiliation:
Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, UK Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
*
Correspondence should be addressed to: Richard W. Walker, Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, UK. Phone: +44 191 293 2709. Email: richard.walker@nhct.nhs.uk.
Get access

Abstract

Background:

The number of people living with dementia in sub-Saharan Africa (SSA) is expected to increase rapidly in the coming decades. However, our understanding of how best to reduce dementia risk in the population is very limited. As a first step in developing intervention strategies to manage dementia risk in this setting, we investigated rates of cognitive decline in a rural population in Tanzania and attempted to identify associated factors.

Methods:

The study was conducted in the rural Hai district of northern Tanzania. In 2014, community-dwelling people aged 65 years and over living in six villages were invited to take part in a cognitive screening program. All participants from four of the six villages were followed-up at two years and cognitive function re-tested. At baseline and follow-up, participants were assessed for functional disability, hypertension, and grip strength (as a measure of frailty). At follow-up, additional assessments of visual acuity, hearing impairment, tobacco and alcohol consumption, and clinical assessment for stroke were completed.

Results:

Baseline and follow-up data were available for 327 people. Fifty people had significant cognitive decline at two-year follow-up. Having no formal education, low grip strength at baseline, being female and having depression at follow-up were independently associated with cognitive decline.

Conclusions:

This is one of the first studies of cognitive decline conducted in SSA. Rates of decline at two years were relatively high. Future work should focus on identification of specific modifiable risk factors for cognitive decline with a view to developing culturally appropriate interventions.

Keywords

dementiacognitive impairmentTanzaniasub-Saharan Africalow- and middle-income countries
Type
Original Research Article
Information
International Psychogeriatrics , Volume 30 , Issue 9: Issue Theme: Quality of Care for Frail Older Adults , September 2018 , pp. 1333 - 1343
Copyright
Copyright © International Psychogeriatric Association 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Akinyemi, R. O. et al. (2014). Profile and determinants of vascular cognitive impairment in African stroke survivors: the CogFAST Nigeria study. Journal of the Neurolological Sciences, 346, 241–249.Google Scholar
Almeida, O. P. and Almeida, S. A. (1999). Short versions of the geriatric depression scale: a study of their validity for the diagnosis of a major depressive episode according to ICD-10 and DSM-IV. International Journal of Geriatric Psychiatry, 14, 858–865.Google Scholar
Auyeung, T. W., Lee, J. S., Leung, J., Kwok, T. and Woo, J. (2014). The selection of a screening test for frailty identification in community-dwelling older adults. Journal of Nutrition, Health and Aging, 18, 199–203.Google Scholar
Baiyewu, O. et al. (2002). Cognitive impairment in community-dwelling older Nigerians: clinical correlates and stability of diagnosis. European Journal of Neurology, 9, 573–580.Google Scholar
Benedict, R. H. and Zgaljardic, D. J. (1998). Practice effects during repeated administrations of memory tests with and without alternate forms. Journal of Clinical and Experimental Neuropsychology, 20, 339–352.Google Scholar
Dewhurst, M. J., Dewhurst, F., Gray, W. K., Chaote, P., Orega, G. P. and Walker, R. W. (2013). The high prevalence of hypertension in rural-dwelling Tanzanian older adults and the disparity between detection, treatment and control: a rule of sixths?. Journal of Human Hypertension, 27, 374–380.Google Scholar
Diniz, B. S., Butters, M. A., Albert, S. M., Dew, M. A. and Reynolds, C. F. (2013). Late-life depression and risk of vascular dementia and Alzheimer's disease: systematic review and meta-analysis of community-based cohort studies. British Journal of Psychiatry, 202, 329–335.Google Scholar
Gray, W. K. et al. (2014). Development and validation of the identification and intervention for dementia in elderly Africans (IDEA) study dementia screening instrument. Journal of Geriatric Psychiatry and Neurology, 27, 110–118.Google Scholar
Gray, W. K. et al. (2016). Community validation of the IDEA study cognitive screen in rural Tanzania. International Journal of Geriatric Psychiatry, 31, 1199–1207.Google Scholar
Hendrie, H. C. et al. (2001). Incidence of dementia and Alzheimer disease in 2 communities: Yoruba residing in Ibadan, Nigeria, and African Americans residing in Indianapolis, Indiana. Journal of the American Medical Association, 285, 739–747.Google Scholar
Jin, Y. P., Di Legge, S., Ostbye, T., Feightner, J. W. and Hachinski, V. (2006). The reciprocal risks of stroke and cognitive impairment in an elderly population. Alzheimer's and Dementia, 2, 171–178.Google Scholar
Koepsell, T. D. and Monsell, S. E. (2012). Reversion from mild cognitive impairment to normal or near-normal cognition: risk factors and prognosis. Neurology, 79, 1591–1598.Google Scholar
Koopman, J. J., van Bodegom, D., van Heemst, D. and Westendorp, R. G. (2015). Handgrip strength, ageing and mortality in rural Africa. Age and Ageing, 44, 465–470.Google Scholar
Leong, D. P. et al. (2016). Reference ranges of handgrip strength from 125,462 healthy adults in 21 countries: a prospective urban rural epidemiologic (PURE) study. Journal of Cachexia, Sarcopenia and Muscle, 7, 535–546.Google Scholar
Longdon, A. R. et al. (2013). The prevalence of dementia in rural Tanzania: a cross-sectional community-based study. International Journal of Geriatric Psychiatry, 28, 728–737.Google Scholar
Matthews, F. E. et al. (2013). A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: results of the cognitive function and ageing study I and II. Lancet, 382, 1405–1412.Google Scholar
Mortamais, M. et al. (2014). Education modulates the impact of white matter lesions on the risk of mild cognitive impairment and dementia. American Journal of Geriatric Psychiatry, 22, 1336–1345.Google Scholar
Ngandu, T. et al. (2015). A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. Lancet, 385, 2255–2263.Google Scholar
Norton, S., Matthews, F. E., Barnes, D. E., Yaffe, K. and Brayne, C. (2014). Potential for primary prevention of Alzheimer's disease: an analysis of population-based data. Lancet Neurology, 13, 788–794.Google Scholar
Paddick, S. M. et al. (2014). The prevalence of dementia subtypes in rural Tanzania. American Journal of Geriatric Psychiatry, 22, 1613–1622.Google Scholar
Paddick, S. M. et al. (2015a). Validation of the identification and intervention for dementia in elderly Africans (IDEA) cognitive screen in Nigeria and Tanzania. BMC Geriatrics, 15, 53.Google Scholar
Paddick, S. M. et al. (2015b). Mild cognitive impairment in Rural Tanzania: prevalence, profile, and outcomes at 4-Year follow-up. American Journal of Geriatric Psychiatry, 23, 950–959.Google Scholar
Paddick, S. M. et al. (2017). Cognitive stimulation therapy as a sustainable intervention for dementia in sub-Saharan Africa: feasibility and clinical efficacy using a stepped-wedge design. International Psychogeriatrics, 29, 979–989.Google Scholar
Paraiso, M. N. et al. (2010). Validation of the use of historical events to estimate the age of subjects aged 65 years and over in Cotonou (Benin). Neuroepidemiology, 35, 12–16.Google Scholar
Prince, M. J. et al. (2015). The burden of disease in older people and implications for health policy and practice. Lancet, 385, 549–562.Google Scholar
Prince, M. et al. (2011). The association between common physical impairments and dementia in low and middle income countries, and, among people with dementia, their association with cognitive function and disability. A 10/66 dementia research group population-based study. International Journal of Geriatric Psychiatry, 26, 511–519.Google Scholar
Prince, M. et al. (2012). Dementia incidence and mortality in middle-income countries, and associations with indicators of cognitive reserve: a 10/66 dementia research group population-based cohort study. Lancet, 380, 50–58.Google Scholar
Prince, M., Guerchet, M. and Prina, M. (2013). Policy Brief for Heads of Government: The Global Impact of Dementia 2013–2050. London, UK: Alzheimer Disease International.Google Scholar
Qiu, C., Winblad, B. and Fratiglioni, L. (2005). The age-dependent relation of blood pressure to cognitive function and dementia. Lancet Neurology, 4, 487–499.Google Scholar
Schrijvers, E. M., Verhaaren, B. F., Koudstaal, P. J., Hofman, A., Ikram, M. A. and Breteler, M. M. (2012). Is dementia incidence declining?: trends in dementia incidence since 1990 in the Rotterdam study. Neurology, 78, 1456–1463.Google Scholar
Schweitzer, I., Tuckwell, V., O'Brien, J. and Ames, D. (2002). Is late onset depression a prodrome to dementia?. International Journal of Geriatric Psychiatry, 17, 997–1005.Google Scholar
Sposato, L. A. et al. (2015). Declining incidence of stroke and dementia: coincidence or prevention opportunity?. Journal of the American Medical Association Neurology, 72, 1529–1531.Google Scholar
Tenu, F., Isingo, R., Zaba, B., Urassa, M. and Todd, J. (2014). Adjusting the HIV prevalence for non-respondents using mortality rates in an open cohort in northwest Tanzania. Tropical Medcine and International Health, 19, 656–663.Google Scholar
The World Bank (2017). Data: Tanzania. Available at: http://data.worldbank.org/country/tanzania.; last accessed 20 October.Google Scholar
Toledo, J. B. et al. (2013). Contribution of cerebrovascular disease in autopsy confirmed neurodegenerative disease cases in the national Alzheimer's coordinating centre. Brain, 136, 2697–2706.Google Scholar
Walker, R. W. et al. (2013). Stroke risk factors within an incident population in urban and rural Tanzania: a prospective, community-based case-control study. Lancet Global Health, 1, e282–e288.Google Scholar
Walker, R. et al. (2010). Stroke incidence in rural and urban Tanzania: a prospective, community-based study. Lancet Neurology, 9, 786–792.Google Scholar