Felicity Dewhurst

The high prevalence of hypertension in rural-dwelling Tanzanian older adults and the disparity between detection, treatment and control: a rule of sixths?

There are limited, reliable data on the prevalence of hypertension in East African populations. The aim of this study was to document the prevalence of hypertension in the rural Hai district of Tanzania. All consenting individuals aged 70 years and over who were living in 12 randomly-selected villages in the district underwent three consecutive sitting blood pressure (BP) measurements. An average of the last two measurements was taken. Prior diagnosis of, and treatment for, hypertension was recorded. Of the 2223 subjects, 1553 (69.9%, 95% CI 68.0–71.8) had hypertension (BP ⩾140/90). Of those with hypertension 733 (47.2%) had isolated systolic hypertension. Only 586 (37.7%) hypertensives had been previously diagnosed, 94 (6.1%) were currently treated and 14 (0.9%) were adequately controlled. This is the first large-scale prevalence study of hypertension in the elderly in sub-Saharan Africa (SSA). Our results approximate to a ‘rule of sixths’; 2/6 of hypertensives were previously detected, 1/6 of those previously detected were on treatment and 1/6 of those on treatment were adequately controlled. Hypertension is a large problem in the elderly population in SSA, and there are a growing number of elderly who are at risk of hypertensive sequelae owing to lack of detection and treatment.

The prevalence of dementia in rural Tanzania: a cross-sectional community-based study.

Despite the growing burden of dementia in low‐income countries, there are few previous data on the prevalence of dementia in sub‐Saharan Africa. The aim of this study was to estimate the prevalence of dementia in those who are 70 years and older in the rural Hai District of Tanzania.

The prevalence of neurological disorders in older people in Tanzania

There are few data on neurological disorders prevalence from low‐ and middle‐income countries, particularly sub‐Saharan Africa (SSA) and none specific to the African elderly. We aimed to determined the prevalence of neurological disorders in those aged 70 years and over in a rural African community.

The prevalence of disability in older people in Hai, Tanzania

BACKGROUND the World Health Organization estimates that more than one billion of the worlds population are disabled. Disability is associated with increasing age and poverty, yet there are few reliable data regarding disability among the elderly in low-income countries. The aim of this study was to accurately document the prevalence of disability in those aged 70 years and over in a community-based setting in sub-Saharan Africa. METHODS we performed a community-based study of people aged 70 years and over in Hai, Tanzania. Participants underwent disability assessment using the culturally non-specific Barthel index (BI), and also clinical assessment for neurological disorders and memory problems. RESULTS in 2,232 participants, the age-adjusted prevalence of severe disability (BI<15) was 3.7% (95% CI: 2.9-4.5) and the age-adjusted prevalence of moderate disability (BI: 15-18) was 6.2% [95% confidence interval (CI): 5.2-7.2]. Increasing age, female gender, memory problems and the presence of neurological disorders were all independent predictors of the presence of disability. CONCLUSION in this study, the average disability level was lower than seen in most high-income countries. This may reflect increased mortality from disabling disease in low-income countries. Disability is likely to increase as the population of low-income countries ages and disease survival improves.

Dementia prevalence estimates in sub-Saharan Africa: comparison of two diagnostic criteria

Background We have previously reported the prevalence of dementia in older adults living in the rural Hai district of Tanzania according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria. The aim of this study was to compare prevalence rates using the DSM-IV criteria with those obtained using the 10/66 diagnostic criteria, which is specifically designed for use in low- and middle-income countries. Methods In phase I, 1,198 people aged 70 and older were screened for dementia. A stratified sample of 296 was then clinically assessed for dementia according to the DSM-IV criteria. In addition, data were collected according to the protocol of the 10/66 Dementia Research Group, which allowed a separate diagnosis of dementia according to these criteria to be established. Results The age-standardised prevalence of clinical DSM-IV dementia was 6.4% (95% confidence interval [CI] 4.9–7.9%) and of ‘10/66 dementia’ was 21.6% (95% CI 17.5–25.7%). Education was a significant predictor of ‘10/66 dementia’, but not of DSM-IV dementia. Conclusions There are large discrepancies in dementia prevalence rates depending on which diagnostic system is used. In rural sub-Saharan Africa, it is not clear whether the association between education and dementia using the 10/66 criteria is a genuine effect or the result of an educational bias within the diagnostic instrument. Despite its possible flaws, the DSM-IV criteria represent an international standard for dementia diagnosis. The 10/66 diagnostic criteria may be more appropriate when identification of early and mild cognitive impairment is required.

Strikingly Low Prevalence of Atrial Fibrillation in Elderly Tanzanians

To determine the prevalence of atrial fibrillation (AF) in individuals aged 70 and older in a rural African community.

Accuracy of algorithms for detection of atrial fibrillation from short duration beat interval recordings

Atrial fibrillation (AF) is characterised by highly variable beat intervals. The aims of the study were to assess the accuracy of AF detection algorithms from short analysis durations and to validate prospectively the accuracy on a large community-based cohort of elderly subjects. Three algorithms for AF detection were evaluated: coefficient of variation (CV), mean successive difference (Δ) and coefficient of sample entropy (COSEn), using two databases of beat interval recordings: 167 recordings of 300 s duration for a range of rhythms acquired in a hospital setting and 2130 recordings of 10s duration acquired in the community. Using the longer recordings receiver operating characteristic (ROC) analysis was used to identify optimal algorithm thresholds and to evaluate analysis durations ranging from 5s to 60s. An ROC area of 93% was obtained at recording duration of 60s but remained above 90% for durations as low as 5s. Prospective analysis on the 2130 recordings gave AF detector sensitivities from 90.5% (CV and Δ) to 95.2% (COSEn), specificities from 89.3% (Δ) to 93.4% (COSEn) and accuracy from 89.3% (Δ) to 93.4% (COSEn), not significantly different to those obtained on the initial database. AF detection algorithms are effective for short analysis durations, offering the prospect of a simple and rapid diagnostic test based on beat intervals alone.

Frailty Screening in Low- and Middle-Income Countries: A Systematic Review.

To conduct a systematic review of frailty screening tools used in low‐ and middle‐income countries (LMICs).

Levels of functional disability in elderly people in Tanzania with dementia, stroke and Parkinson’s disease

Background Disability is associated with increasing age and poverty, yet there are few reliable data regarding disability amongst the elderly in low-income countries. The aim of this study was to compare disability levels for three of the most common neurological, non-communicable diseases: dementia, stroke and Parkinson’s disease (PD). Methods We performed a community-based study of people aged 70 years and over in 12 randomly selected villages in the rural Hai district of Tanzania. Participants underwent disability assessment using the Barthel Index, and clinical assessment for dementia, stroke and PD. Results In a representative cohort of 2232 people aged 70 years and over, there were 54 cases of stroke, 12 cases of PD and estimated (by extrapolation from a sub-sample of 1198 people) to be 112 cases of dementia. People with stroke were the most disabled, with 62.9% having moderate or severe disability. Levels of moderate or severe disability were 41.2% in people with dementia and 50.0% in people with PD. However, the higher prevalence of dementia meant that, at a population level, it was associated with similar levels of disability as stroke, with 18.5% of 249 people identified as having moderate or severe disability having dementia, compared to 13.7% for stroke and 2.4% for PD. Conclusions Levels of disability from these conditions is high and is likely to increase with demographic ageing. Innovative, community-based strategies to reduce disability levels should be investigated.

A comparison of caregiver burden in older persons and persons with Parkinson's disease or dementia in sub-Saharan Africa

BACKGROUND Caregiver burden includes the many physical, mental and socio-economic problems arising from caring for individuals with chronic and disabling diseases. Being a carer in sub-Saharan Africa (SSA), where little is known about chronic neurological conditions, may be extremely demanding. Conversely, multigenerational living may allow sharing of care among many caregivers. We wished to determine the relative burden of caring for two chronic neurodegenerative conditions (Parkinsons disease (PD) and dementia) in rural Tanzania. METHODS All surviving patients from a PD prevalence study, newly identified people with PD from a neurological disorders study and all people with dementia from a dementia prevalence study in Hai, rural Tanzania, were invited to participate. The Zarit Burden Interview (ZBI) was used to determine level of caregiver strain (higher score reflects more strain). RESULTS Of 25 PD patients ZBI was recorded in 20 (14 male). Five had no identifiable carer as they were largely independent. Three had PD dementia (PDD). Of 75 people with dementia (excluding 3 PDD), 43 (32 female) completed the ZBI. For the other 32, the caregivers felt the care they provided was a normal intergenerational expectation. Median ages were 78.5 and 85 years for PD and dementia, respectively. Median ZBI was 30.5 for PD and 14 for dementia (U = 166.0, z = -3.913, p < 0.001). Disease duration and disease type (PD or dementia) were univariate predictor of ZBI score, although only disease type was predictive by multivariable linear regression. CONCLUSIONS Caring for an individual with PD may be more burdensome than caring for an individual with dementia in SSA. People with more advanced PD had higher caregiver burden.