Blood pressure and the hypertension care cascade in The Gambia: Findings from a nationwide survey

Community treatment of hypertension in sub-Saharan Africa is hampered by gaps at several stages of the care cascade. We compared blood pressure (BP) levels (systolic, diastolic and pulse pressures) in four groups of participants by hypertension and treatment status. We conducted a nationally representative survey of adults 35 years and older using a multistage sampling strategy based on the 2013 Gambia Population and Housing Census. The BP measurements were taken in triplicate 5 min apart, and the average of the last two measurements was used for analysis. Systolic and diastolic BP levels and pulse pressure were compared by hypertension status using mean and 95% confidence intervals (CI). 53.1% of the sample were normotensive with mean systolic BP (SBP) of 119.2 mmHg (95% CI, 118.7-119.6) and diastolic BP (DBP) of 78.1 mmHg (77.8-78.3). Among individuals with hypertension, mean SBP was 148.7 mmHg (147.7-149.7) among those unaware of their hypertension, 152.2 mmHg (151.0-153.5) among treated individuals and was highest in untreated individuals at 159.3 mmHg (157.3-161.2). The findings were similar for DBP levels, being 93.9 mmHg (93.4-94.4) among the unaware, 95.1 mmHg (94.4-95.8) among the treated and highest at 99.1 mmHg (98.1-100.2) in untreated participants. SBP and DBP were higher in men, and SBP was as expected higher in those aged ≥55 years. BP level was similar in urban and rural areas. Our data shows high BP levels among participants with hypertension including those receiving treatment. Efforts to reduce the health burden of hypertension will require inputs at all levels of the care cascade.

Prevalence of hypertension, diabetes, obesity, multimorbidity, and related risk factors among adult Gambians: a cross-sectional nationwide study

BACKGROUND

As countries progress through economic and demographic transition, chronic non-communicable diseases (NCDs) overtake a previous burden of infectious diseases. We investigated the prevalence of hypertension, diabetes, obesity, and multimorbidity in older adults in The Gambia.

METHODS

We embedded a survey on NCDs into the nationally representative 2019 Gambia National Eye Health Survey of adults aged 35 years or older. We measured anthropometrics, capillary blood glucose, and blood pressure together with sociodemographic information, personal and family health history, and information on smoking and alcohol consumption. Hypertension was defined as systolic blood pressure of 140 mmHg or more, diastolic blood pressure of 90 mmHg or more, or receiving treatment for hypertension. Diabetes was defined as fasting capillary blood glucose of 7 mmol/L or more, random blood glucose of 11·1mmol/L or more, or previous diagnosis or treatment for diabetes. Overweight was defined as BMI of 25-29·9 kg/m2 and obesity as 30 kg/m2 or more. Multimorbidity was defined as the coexistence of two or more conditions. We calculated weighted crude and adjusted estimates for each outcome by sex, residence, and selected sociodemographic factors.

FINDINGS

We analysed data from 9188 participants (5039 [54·8%] from urban areas, 6478 [70·5%] women). The prevalence of hypertension was 47·0%; 2259 (49·3%) women, 2052 (44·7%) men. The prevalence increased with age, increasing from 30% in those aged 35-45 years to over 75% in those aged 75 years and older. Overweight and obesity increased the odds of hypertension, and underweight reduced the odds. The prevalence of diabetes was 6·3% (322 [7·0%] women, 255 [5·6%] men), increasing from 3·8% in those aged 35-44 years to 9·1% in those aged 65-75 years, and then declining. Diabetes was much more common among urban residents, especially in women (peaking at 13% by age 65 years). Diabetes was strongly associated with BMI and wealth index. The prevalence of obesity was 12·0% and was notably higher in women than men (880 [20·2%] vs 170 [3·9%]). Multimorbidity was present in 932 (10·7%), and was more common in women than men (694 [15·9] vs 238 [5·5]). The prevalence of smoking was 9·7%; 5 (0·1%) women, 889 (19·3%) men. Alcohol consumption in the past year was negligible.

INTERPRETATION

We have documented high levels of NCDs and associated risk factors in Gambian adults. This presents a major stress on the country's fragile health system that requires an urgent, concerted, and targeted mutisectoral strategy.

FUNDING

The Queen Elizabeth Diamond Jubilee Trust and Wellcome Trust.

Evaluating the hypertension care cascade in middle-aged and older adults in The Gambia: findings from a nationwide survey

Background

Hypertension is a major public health problem in sub-Saharan Africa with poor treatment coverage and high case-fatality rates. This requires assessment of healthcare performance to identify areas where intervention is most needed. To identify areas where health resources should be most efficiently targeted, we assessed the hypertension care cascade i.e., loss and retention across the various stages of care, in Gambian adults aged 35 years and above.

Methods

This study was embedded within the nationally representative 2019 Gambia National Eye Health Survey of adults ≥35 years. We constructed a hypertension care cascade with four categories: prevalence of hypertension (defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg, and/or current use of medication prescribed for hypertension); those aware of their diagnosis; those treated; and those with a controlled blood pressure (defined as blood pressure <140/90 mmHg). Analyses were age- and sex-standardised to the population structure of The Gambia. Logistic regression was used to assess the socio-demographic factors associated with prevalence, awareness, treatment and control of hypertension.

Findings

Of 9171 participants with data for blood pressure, the prevalence of hypertension was 47.0%. Among people with hypertension, the prevalence of awareness was 54.7%, the prevalence of hypertension treatment was 32.5%, and prevalence of control was 10.0% with little difference between urban and rural residence. The cascade of care performance was better in women. However, there was no difference in achieving blood pressure control between men and women who were receiving treatment. Female sex, older age and higher body mass index were associated with higher hypertension awareness whilst having an occupation compared to being unemployed was associated with higher odds of being treated. Patients in the underweight category had higher odds of achieving blood pressure control.

Interpretation

There is a high prevalence of hypertension and low performance of the health care system that impact on the hypertension care cascade among middle-aged and older adults in The Gambia. Addressing the full cascade will be paramount especially in reducing the mounting prevalence and improving diagnosis of patients with hypertension, where the greatest dividends will be gained.

Funding

The Queen Elizabeth Diamond Jubilee Trust, Wellcome Trust.

The Gambia Trachomatous Trichiasis Surveys: Results from Five Evaluation Units Confirm Attainment of Trachoma Elimination Thresholds

INTRODUCTION

Trichiasis is present when in-turned eyelashes touch the eyeball. It may result in permanent vision loss. Trachomatous trichiasis (TT) is caused by multiple rounds of inflammation associated with conjunctival Chlamydia trachomatis infection. Surveys have been designed to estimate the prevalence of TT in evaluation units (EUs) of trachoma-endemic countries in order to help develop appropriate programme-level plans. In this study, TT-only surveys were conducted in five EUs of The Gambia to determine whether further intensive programmatic action was required.

METHODS

Two-stage cluster sampling was used to select 27 villages per EU and ~25 households per village. Graders assessed the TT status of individuals aged ≥15 years in each selected household, including the presence or absence of conjunctival scarring in those with TT.

RESULTS

From February to March 2019, 11595 people aged ≥15 years were examined. A total of 34 cases of TT were identified. All five EUs had an age- and gender-adjusted prevalence of TT unknown to the health system <0.2%. Three of five EUs had a prevalence of 0.0%.

CONCLUSION

Using these and other previously collected data, in 2021, The Gambia was validated as having achieved national elimination of trachoma as a public health problem. Trachoma is still present in the population, but as its prevalence is low, it is unlikely that today's youth will experience the exposure to C. trachomatis required to precipitate TT. The Gambia demonstrates that with political will and consistent application of human and financial resources, trachoma can be eliminated as a public health problem.

Socioeconomic position and eye health outcomes: identifying inequality in rapid population-based surveys

OBJECTIVE

Monitoring health outcomes disaggregated by socioeconomic position (SEP) is crucial to ensure no one is left behind in efforts to achieve universal health coverage. In eye health planning, rapid population surveys are most commonly implemented; these need an SEP measure that is feasible to collect within the constraints of a streamlined examination protocol. We aimed to assess whether each of four SEP measures identified inequality-an underserved group or socioeconomic gradient-in key eye health outcomes.

DESIGN

Population-based cross-sectional survey.

PARTICIPANTS

A subset of 4020 adults 50 years and older from a nationally representative sample of 9188 adults aged 35 years and older in The Gambia.

OUTCOME MEASURES

Blindness (presenting visual acuity (PVA) <3/60), any vision impairment (VI) (PVA <6/12), cataract surgical coverage (CSC) and effective cataract surgical coverage (eCSC) at two operable cataract thresholds (<6/12 and <6/60) analysed by one objective asset-based measure (EquityTool) and three subjective measures of relative SEP (a self-reported economic ladder question and self-reported household food adequacy and income sufficiency).

RESULTS

Subjective household food adequacy and income sufficiency demonstrated a socioeconomic gradient (queuing pattern) in point estimates of any VI and CSC and eCSC at both operable cataract thresholds. Any VI, CSC <6/60 and eCSC <6/60 were worse among people who reported inadequate household food compared with those with just adequate food. Any VI and CSC <6/60 were worse among people who reported not enough household income compared with those with just enough income. Neither the subjective economic ladder question nor the objective asset-wealth measure demonstrated any socioeconomic gradient or pattern of inequality in any of the eye health outcomes.

CONCLUSION

We recommend pilot-testing self-reported food adequacy and income sufficiency as SEP variables in vision and eye health surveys in other locations, including assessing the acceptability, reliability and repeatability of each question.

Prevalence of blindness and distance vision impairment in the Gambia across three decades of eye health programming

BACKGROUND/AIMS

The 1986 Gambia National Eye Health Survey provided baseline data for a National Eye Health Programme. A second survey in 1996 evaluated changes in population eye health a decade later. We completed a third survey in 2019, to determine the current state of population eye health, considering service developments and demographic change.

METHODS

We estimated prevalence and causes of vision impairment (VI) in a nationally representative population-based sample of adults 35 years and older. We used multistage cluster random sampling to sample 10 800 adults 35 and above in 360 clusters of 30. We measured monocular distance visual acuity (uncorrected and with available correction) using Peek Acuity. Participants with either eye uncorrected or presenting (with available correction) acuity <6/12 were retested with pinhole and refraction, and dilated exams were completed on all eyes by ophthalmologists using a direct ophthalmoscope, slit lamp and 90 D lens.

RESULTS

We examined 9188 participants (response rate 83%). The 2013 census age-sex adjusted prevalence of blindness (presenting acuity<3/60 in better seeing eye) was 1.2% (95% CI 0.9 to 1.4) and of moderate or severe VI (MSVI,<6/18 to ≥3/60) was 8.9% (95% CI 9.1 to 9.7). Prevalence of all distance VI (<6/12) was 13.4% (12.4-14.4). Compared with 1996, the relative risk of blindness decreased (risk ratio 0.7, 95% CI 0.5 to 1.0) and MSVI increased (risk ratio 1.5, 95% CI 1.2 to 0.17).

CONCLUSION

Significant progress has been made to reduce blindness and increase access to eye health across the Gambia, with further work is needed to decrease the risk of MSVI.

Estimating Need for Glasses and Hearing Aids in The Gambia: Results from a National Survey and Comparison of Clinical Impairment and Self-Report Assessment Approaches

Few estimates are available of the need for assistive devices (ADs) in African settings. This study aimed to estimate population-level need for glasses and hearing aids in The Gambia based on (1) clinical impairment assessment, and (2) self-reported AD awareness, and explore the relationship between the two methods. The Gambia 2019 National Eye Health Survey is a nationally representative population-based sample of 9188 adults aged 35+ years. Participants underwent standardised clinical vision assessments including the need for glasses (distance and near). Approximately 25% of the sample underwent clinical assessment of hearing and hearing aid need. Data were also collected on self-reported awareness, need and access barriers to vision and hearing ADs. Overall, 5.6% of the study population needed distance glasses (95% CI 5.0-6.3), 45.9% (95% CI 44.2-47.5) needed near glasses and 25.5% (95% CI 22.2-29.2) needed hearing aids. Coverage for each AD was very low (<4%). The agreement between self-report and clinical impairment assessment for AD need was poor. In conclusion, there is high prevalence and very low coverage for distance glasses, near glasses and hearing aids in The Gambia. Self-report measures alone will not provide an accurate estimate of AD need.

The Gambia National Eye Health Survey 2019: survey protocol

Two national surveys of vision impairment and blindness were undertaken in The Gambia in 1986 and 1996. These provided data for the inception of The Gambia's National Eye Health Programme (NEHP) within the Ministry of Health and Social Welfare. There have been important developments in the eye health services provided by the NEHP in the last 20 years. At the same time, the population has also undergone major demographic changes that may have led to substantial changes in the burden of eye disease. We conducted a National Eye Health Survey of vision impairment, blindness and its comorbidities in adults in The Gambia in 2019. We examined a nationally representative population-based sample of adults 35 years and above to permit direct comparison with the data available from the previous surveys. Alongside a comprehensive vision and eye examination, the survey provides nationally representative data on important comorbidities in this population: diabetes, hypertension, obesity, hearing impairment, disability and mental health. Secondly, it estimates access to assistive technologies and eye health services. Thirdly, it is powered to allow a five-year follow up cohort study to measure the incidence and progression of eye disease.

The Gambia National Eye Health Survey 2019: survey protocol

Two national surveys of vision impairment and blindness were undertaken in The Gambia in 1986 and 1996. These provided data for the inception of The Gambia's National Eye Health Programme (NEHP) within the Ministry of Health and Social Welfare. There have been important developments in the eye health services provided by the NEHP in the last 20 years. At the same time, the population has also undergone major demographic changes that may have led to substantial changes in the burden of eye disease. We conducted a National Eye Health Survey of vision impairment, blindness and its comorbidities in adults in The Gambia in 2019. We examined a nationally representative population-based sample of adults 35 years and above to permit direct comparison with the data available from the previous surveys. Alongside a comprehensive vision and eye examination, the survey provides nationally representative data on important comorbidities in this population: diabetes, hypertension, obesity, hearing impairment, disability and mental health. Secondly, it estimates access to assistive technologies and eye health services. Thirdly, it is powered to allow a five-year follow up cohort study to measure the incidence and progression of eye disease.

Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry

IMPORTANCE

Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders.

OBJECTIVES

To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma.

DESIGN, SETTINGS, AND PARTICIPANTS

A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14 917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma.

EXPOSURES

Genetic variants associated with primary open-angle glaucoma.

MAIN OUTCOMES AND MEASURES

Presence of primary open-angle glaucoma. Genome-wide significance was defined as P < 5 × 10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data.

RESULTS

A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-β A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; P = 2 × 10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14 917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; P < .001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; P = 4 × 10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry.

CONCLUSIONS AND RELEVANCE

In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies.

Antenatal care in The Gambia: missed opportunity for information, education and communication

BACKGROUND

Antenatal care is widely established and provides an opportunity to inform and educate pregnant women about pregnancy, childbirth and care of the newborn. It is expected that this would assist the women in making choices that would contribute to good pregnancy outcome. We examined the provision of information and education in antenatal clinics from the perspective of pregnant women attending these clinics.

METHODS

A cross sectional survey of 457 pregnant women attending six urban and six rural antenatal clinics in the largest health division in The Gambia was undertaken. The women were interviewed using modified antenatal client exit interview and antenatal record review questionnaires from the WHO Safe Motherhood Needs Assessment kit. Differences between women attending urban and rural clinics were assessed using the Chi-square test. Relative risks with 95% confidence intervals are presented.

RESULTS

Ninety percent of those interviewed had attended the antenatal clinic more than once and 52% four or more times. Most pregnant women (70.5%) said they spent 3 minutes or less with the antenatal care provider. About 35% recalled they were informed or educated on diet and nutrition, 30.4% on care of the baby, 23.6% on family planning, 22.8% on place of birth and 19.3% on what to do if there was a complication. About 25% of pregnant women said they were given information about the progress of their pregnancy after consultation and only 12.8% asked their provider any question. Awareness of danger signs was low. The proportions of women that recognised signs of danger were 28.9% for anaemia, 24.6% for hypertension, 14.8% for haemorrhage, 12.9% for fever and 5% for puerperal sepsis. Prolonged labour was not recognised as a danger sign. Women attending rural antenatal clinics were 1.6 times more likely to recognise signs of anaemia and hypertension as indicative of danger compared to women attending urban antenatal clinics.

CONCLUSION

Information, education and communication during antenatal care in the largest health division are poor. Pregnant women are ill-equipped to make appropriate choices especially when they are in danger. This contributes to the persistence of high maternal mortality ratios in the country.