Rates and predictors of three-year mortality in older people in rural Tanzania

The association between disability and all-cause mortality in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

There are 1·3 billion people with disabilities globally. On average, they have poorer health than their non-disabled peers, but the extent of increased risk of premature mortality is unknown. We aimed to systematically review the association between disability and mortality in low-income and middle-income countries (LMICs).

METHODS

We searched MEDLINE, Global Health, PsycINFO, and EMBASE from Jan 1, 1990 to Nov 14, 2022. Longitudinal epidemiological studies in any language with a comparator group that measured the association between disability and all-cause mortality in people of any age were eligible for inclusion. Two reviewers independently assessed study eligibility, extracted data, and assessed risk of bias. We used a random-effects meta-analysis to calculate the pooled hazard ratio (HR) for all-cause mortality by disability status. We then conducted meta-analyses separately for different impairment and age groups.

FINDINGS

We identified 6146 unique articles, of which 70 studies (81 cohorts) were included in the systematic review, from 22 countries. There was variability in the methods used to assess and report disability and mortality. The meta-analysis included 54 studies, representing 62 cohorts (comprising 270 571 people with disabilities). Pooled HRs for all-cause mortality were 2·02 (95% CI 1·77-2·30) for people with disabilities versus those without disabilities, with high heterogeneity between studies (τ2=0·23, I2=98%). This association varied by impairment type: from 1·36 (1·17-1·57) for visual impairment to 3·95 (1·60-9·74) for multiple impairments. The association was highest for children younger than 18 years (4·46, [3·01-6·59]) and lower in people aged 15-49 years (2·45 [1·21-4·97]) and people older than 60 years (1·97 [1·65-2·36]).

INTERPRETATION

People with disabilities had a two-fold higher mortality rate than people without disabilities in LMICs. Interventions are needed to improve the health of people with disabilities and reduce their higher mortality rate.

FUNDING

UK National Institute for Health and Care Research; and UK Foreign, Commonwealth and Development Office.

The association between disability and mortality: a mixed-methods study

BACKGROUND

Globally, 1·3 billion people have a disability and are more likely to experience poor health than the general population. However, little is known about the mortality or life expectancy gaps experienced by people with disabilities. We aimed to undertake a systematic review and meta-analysis of the association between disability and mortality, compare these findings to the evidence on the association of impairment types and mortality, and model the estimated life expectancy gap experienced by people with disabilities.

METHODS

We did a mixed-methods study, which included a systematic review and meta-analysis, umbrella review, and life expectancy modelling. For the systematic review and meta-analysis, we searched MEDLINE, Global Health, PsycINFO, and Embase for studies published in English between Jan 1, 2007, and June 7, 2023, investigating the association of mortality and disability. We included prospective and retrospective cohort studies and randomised controlled trials with a baseline assessment of disability and a longitudinal assessment of all-cause mortality or cause-specific mortality. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. We did a random-effects meta-analysis to calculate a pooled estimate of the mortality rate ratio for people with disabilities compared with those without disabilities. We did an umbrella review of meta-analyses examining the association between different impairment types and mortality. We used life table modelling to translate the mortality rate ratio into an estimate of the life expectancy gap between people with disabilities and the general population. The systematic review and meta-analysis is registered with PROSPERO, CRD42023433374.

FINDINGS

Our search identified 3731 articles, of which 42 studies were included in the systematic review. The meta-analysis included 31 studies. Pooled estimates showed that all-cause mortality was 2·24 times (95% CI 1·84-2·72) higher in people with disabilities than among people without disabilities, although heterogeneity between the studies was high (τ2=0·28, I2=100%). Modelling indicated a median gap in life expectancy of 13·8 years (95% CI 13·1-14·5) by disability status. Cause-specific mortality was also higher for people with disabilities, including for cancer, COVID-19, cardiovascular disease, and suicide. The umbrella review identified nine meta-analyses, which showed consistently elevated mortality rates among people with different impairment types.

INTERPRETATION

Mortality inequities experienced by people with disabilities necessitate health system changes and efforts to address inclusion and the social determinants of health.

FUNDING

National Institute for Health and Care Research, Rhodes Scholarship, Indonesia Endowment Funds for Education, Foreign, Commonwealth and Development Office (Programme for Evidence to Inform Disability Action), and the Arts and Humanities Research Council.

Cognition in older adults in Uganda: Correlates, trends over time and association with mortality in prospective population study

Dementia is an important and growing issue in sub-Saharan Africa, but epidemiological data are lacking. Risk factors may differ from other regions due to high stroke incidence and HIV prevalence. Understanding the epidemiology of cognition in older adults in Africa is crucial for informing public health strategies to improve the lives of people with dementia and their carers. The Wellbeing of Older People Study in Uganda is an open cohort of adults aged 50+ with and without HIV, established in 2009. Detailed socio-demographic and health data have been collected at four waves spanning 10 years, including cognitive assessment using internationally validated WHO-recommended tests: verbal recall, digit span, and verbal fluency. Mortality data was collected until the end of the fourth wave (2019). We examined associations of low baseline cognition scores and changes in cognition score over time using random effects modelling, care needs of people with lower cognition scores, and the relationship between cognition score and mortality. Data were collected on 811 participants. Older age, lower educational attainment, lower socio-economic position, and extremes of BMI were associated with lower cognition scores. Cognition scores declined faster at older ages, but rate of decline was not associated with cardiovascular disease or HIV at baseline. People with lower cognition scores required more assistance with Activities of Daily Living, but mortality rates were similar across the range of cognition scores. The crucial next step will be to investigate types and presentation of clinical dementia in this cohort, so we can better understand the clinical relevance of these findings to inform public health planning.

Social vulnerability, frailty and their association with mortality in older adults living in rural Tanzania

Background

Social vulnerability correlates with frailty and is associated with mortality and disability. However, few studies have investigated this relationship outside of high-income country settings. This study aimed to produce and analyze a culturally adapted social vulnerability index (SVI) to investigate the relationship between social vulnerability, frailty, and mortality in older adults in Tanzania.

Methods

An SVI was produced using data from a cohort study investigating frailty in older adults in Tanzania. Variables were selected based on previous SVI studies using the categories established by Andrew et al. from the Canadian Study of Health and Aging, and National Population Health Survey. The SVI distribution was examined and compared with a frailty index (FI) produced from the same sample, using mutually exclusive variables. Cox regression survival analysis was used to investigate the association between social vulnerability, frailty, and mortality.

Results

A stratified cohort of 235 individuals were included in the study at baseline, with a mean age of 75.2 (SD 11.5). Twenty-six participants died within the follow-up period, with a mean of 503 days (range: 405–568) following the initial assessment. The SVI had a median score of 0.47 (interquartile range: 0.23, range: 0.14–0.86). Social vulnerability significantly predicted mortality when adjusting for age and gender, but not when also adjusting for frailty.

Conclusions

Social vulnerability can be successfully operationalized and culturally adapted in Tanzania. Social vulnerability is associated with mortality in Tanzania, but not independently of frailty.

Ten-Year Trend Analysis of Mortality Due to External Causes of Injury in People with Disabilities, South Korea, 2008-2017

External causes of injury are major contributors to mortality among people with disabilities. We analyzed the 10-year trend (2008-2017) of mortality attributed to external causes of injury among people with disabilities. We conducted an observational, population-based, retrospective, cross-sectional study among people with disabilities in South Korea. The database was compiled by merging two data sets: registered people with disabilities during 2008-2017 from the Ministry of Health and Welfare, and the data published by the Korea National Statistical Office. Between 2008 and 2017, the all-cause mortality among people with disabilities showed a rising trend and increased from 2641 per 100,000 in 2008 to 2751 per 100,000 in 2017. During this 10-year period, 6.5-9.2% of the total number of deaths were caused by injuries. Disabilities that were associated with a high crude mortality rate shared the same three most frequent causes of death: suicide, motor vehicle crashes, and falling. Mortality due to external causes of injury increased among older people with disabilities. Thus, effective strategies are required to decrease preventable deaths caused by unintentional injuries among people with disabilities.

Self-reported disability in relation to mortality in rural Malawi: a longitudinal study of over 16 000 adults

OBJECTIVES

We investigated whether self-reported disability was associated with mortality in adults in rural Malawi.

SETTING

Karonga Health and Demographic Surveillance Site (HDSS), Northern Malawi.

PARTICIPANTS

All adults aged 18 and over residing in the HDSS were eligible to participate. During annual censuses in 2014 and 2015, participants were asked if they experienced difficulty in any of six functional domains and were classified as having disabilities if they reported 'a lot of difficulty' or 'can't do at all' in any domain. Mortality data were collected until 31 December 2017. 16 748 participants (10 153 women and 6595 men) were followed up for a median of 29 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

We used Poisson regression to examine the relationship between disability and all-cause mortality adjusting for confounders. We assessed whether this relationship altered in the context of obesity, hypertension, diabetes or HIV. We also evaluated whether mortality from non-communicable diseases (NCD) was higher among people who had reported disability, as determined by verbal autopsy.

RESULTS

At baseline, 7.6% reported a disability and the overall adult mortality rate was 9.1/1000 person-years. Adults reporting disability had an all-cause mortality rate 2.70 times higher than those without, and mortality rate from NCDs 2.33 times higher than those without.

CONCLUSIONS

Self-reported disability predicts mortality at all adult ages in rural Malawi. Interventions to improve access to healthcare and other services are needed.

Hypertension in older adults in Africa: A systematic review and meta-analysis

BACKGROUND

Hypertension is the leading driver of cardiovascular disease deaths in Africa. Its prevalence is highest in older populations. Yet, this group has received little attention in many African countries. We conducted a systematic review and meta-analysis (PROSPERO registration: CRD42017056474) to estimate the prevalence of hypertension in older adults living in Africa.

METHODS

We searched grey literature and major electronic databases including PubMed and Embase for population-based studies and published between 1 January 1980 to 28 May 2018 reporting the prevalence of hypertension for adults aged ≥50 years living in Africa. We employed a random effects model to estimate the pooled prevalence across included studies.

FINDINGS

We screened 10,719 articles and retrieved 103 full-text articles to evaluate for inclusion in the review. Thirty-four unique studies providing 37 data points on 43,025 individuals in 15 African countries were analyzed. The prevalence of hypertension ranged from 22.3% to 90.0% from the individual studies while the overall pooled prevalence was 57.0% (95% CI 52%-61%). The prevalence was not statistically significantly different by sex, residence, or African sub-region. In individual studies, older age and overweight/obesity were independently associated with hypertension. Twenty-nine (78%) data points were deemed to be of low- or moderate-risk of bias. Eliminating high-risk bias studies made little difference to the pooled estimate of hypertension. Sensitivity analyses, omitting one study at a time, identified three studies with significant but relatively small impact on the pooled estimate. We observed substantial heterogeneity (I2 = 98.9%) across the studies which was further explored by meta-regression analyses. Overall, the GRADE assessment suggested moderate quality evidence in the results.

CONCLUSION

The persistent high prevalence of hypertension among older adults in Africa, even in rural populations warrants more attention to the cardiovascular health of this group by public health authorities.

Retinal imaging to identify target organ damage in older Africans: A pilot study

By 2030, sub-Saharan Africa is forecast to see the steepest rise in the number of people with hypertension of any world region. Hypertensive retinopathy is known to be a common complication of hypertension in developed countries and some studies suggest it is associated with the presence of other hypertension-related end-organ damage (EOD) such as stroke and cardiovascular disease. In Tanzania hypertension is relatively more common than in other parts of sub-Saharan Africa, especially in the older population; however, the prevalence of hypertensive retinopathy and its association with EOD remain unknown. The authors conducted a cross-sectional study of elderly, community-dwelling, rural Tanzanians to determine the prevalence of hypertensive retinopathy and its association with hypertension and other forms of EOD. Hypertensive retinopathy was diagnosed based on retinal imaging. In a cohort of 61 patients with gradable images, the authors found the overall prevalence of hypertensive retinopathy to be 64% (n = 39), which was strongly associated with hypertension (X² [1] = 4.207, P = .004), with a significant trend towards more severe retinopathy with more severe hypertension (r = .377, P = .003). The authors did not find hypertensive retinopathy to be associated with other forms of EOD. Hypertensive retinopathy is highly prevalent in this population and is associated in most but not all cases with hypertension. These findings do not suggest that it could be used as a screening tool for EOD, but it is important to identify and educate patients with retinopathy about possible complications of the condition.

Hypertension in a resource-limited setting: Is it associated with end organ damage in older adults in rural Tanzania?

Few data from sub-Saharan Africa exist on the effects of hypertension on the organs of the human body. We aimed to establish the prevalence of hypertensive end organ damage (EOD) in an elderly cohort of Tanzanians. The population aged 70 years and over of 2 villages in northern Tanzania (n = 246), had blood pressure (BP) data available from 2010 and 2013, and underwent in-depth follow-up for markers of hypertensive EOD in 2016. Assessment included ankle-brachial pressure index, lying-standing BP, electrocardiogram, and mid-stream urine dip. Sustained hypertension (those with hypertension at all 3 assessments) was found in 129 (52.4% subjects). Of the entire cohort, 13.9% had left ventricular hypertrophy and 26.4% had peripheral arterial disease, both of which were associated with sustained hypertension, although orthostatic hypotension, stroke, proteinuria, and arterial stiffening were not. Further investigation, particularly in younger age groups, is merited if hypertension-associated morbidity is to be controlled.