Cardiovascular disease risk profile and management among people 40 years of age and above in Bo, Sierra Leone: A cross-sectional study

Introduction Access to care for cardiovascular disease risk factors (CVDRFs) in low- and middle-income countries is limited. We aimed to describe the need and access to care for people with CVDRF and the preparedness of the health system to treat these in Bo, Sierra Leone. Methods Data from a 2018 household survey conducted in Bo, Sierra Leone, was analysed. Demographic, anthropometric and clinical data on CVDRF (hypertension, diabetes mellitus or dyslipidaemia) from randomly sampled individuals 40 years of age and above were collected. Future risk of CVD was calculated using the World Health Organisation–International Society of Hypertension (WHO-ISH) calculator with high risk defined as >20% risk over 10 years. Requirement for treatment was based on WHO package of essential non-communicable (PEN) disease guidelines (which use a risk-based approach) or requiring treatment for individual CVDRF; whether participants were on treatment was used to determine whether care needs were met. Multivariable regression was used to test associations between individual characteristics and outcomes. Data from the most recent WHO Service Availability and Readiness Assessment (SARA) were used to create a score reflecting health system preparedness to treat CVDRF, and compared to that for HIV. Results 2071 individual participants were included. Most participants (n = 1715 [94.0%]) had low CVD risk; 423 (20.6%) and 431 (52.3%) required treatment based upon WHO PEN guidelines or individual CVDRF, respectively. Sixty-eight (15.8%) had met-need for treatment determined by WHO guidelines, whilst 84 (19.3%) for individual CVDRF. Living in urban areas, having education, being older, single/widowed/divorced, or wealthy were independently associated with met need. Overall facility readiness scores for CVD/CVDRF care for all facilities in Bo district was 16.8%, compared to 41% for HIV. Conclusion The number of people who require treatment for CVDRF in Sierra Leone is substantially lower based on WHO guidelines compared to CVDRF. CVDRF care needs are not met equitably, and facility readiness to provide care is low. This is an analysis of the data from a 2018 household survey conducted in Bo, Sierra Leone and data from the most recent WHO Service Availability and Readiness Assessment (SARA) done in 2017 [2, 17]. Sierra Leone is located in West Africa. It is one of the least developed countries in the world. In 2017, the percentage of the gross domestic product (GDP) spent on health was 8.75% [18]. However, domestic general government health expenditure is only 1.23% of GDP; out of pocket (OOP) expenditure contributes 55.18% of total health expenditure and the external funding of health is high [18, 19]. The focus of external funding for health has been on communicable diseases, whereas NCDs (of which CVD and CVDRF are only a subset) received only $510,000 of a total of $170 million in 2017 [20, 21]. By contrast, HIV services received $30 million [20, 21]. The study was carried out in Bo district in the Southern province of Sierra Leone. It is the fifth most populous district in the country and comprises 15 rural chiefdoms and 24 urban areas [22]. Its district headquarters, Bo, is the second largest city in Sierra Leone [22]. The district has a recorded population of 575,478 constituting 8.1% of the country’s population with the majority living in rural areas (66.1%) [22]. Adults aged 40 years of age and above, among whom this study was done, comprise 17.4% of the total population [22]. In Bo district, healthcare is provided by a mix of public and private–for profit or not for profit–facilities at the primary or secondary healthcare levels [22]. The study sample included were men or women 40 years of age and above, this age group was selected given the increasing risk of CVDRF with age and to be congruent with other similar surveys [2, 23–26]. The surveys were developed in English, but translated into Mende or Krio by a bilingual speak, and back translated into English to check the accuracy of the translation. Numbers of participants to sample from urban and rural areas were calculated based on the proportions of people known to be living in these areas. The population in the area was not well delineated in census data, therefore sampling proceeded by first randomly selecting from rural chiefdoms or urban sub districts and, for the rural areas, by further randomly selecting villages or settlements from each chiefdom. Seven rural chiefdoms or urban sub districts were randomly selected to participate, and two settlements or villages were further randomly selected within each rural chiefdom. Data were collected electronically by trained data collectors using ODK software. Survey questions asked gender, age, marital status (as single, cohabiting, currently married, multiple partners, divorced, widowed, or refused), and highest level of education completed (no formal schooling, primary, junior secondary, senior secondary, higher education, or refused). There were 49 questions on house construction materials and household assets. Questions on smoking, awareness of presence of CVD or CVDRF, and whether respondents were on treatment for these risk factors were based on the WHO Stepwise survey; for those who reported suffering from a CVDRF, whether care had been accessed was asked. Blood pressure was measured in the seated position using an Omron M6 AC LED Monitor. Three measurements were taken five minutes apart. Blood samples were taken in the morning after an 8 hour overnight fast. Glucose and cholesterol were measured using the Accutrend® Plus Blood Test Meter (Diagnostics Roche) point of care device, with cholesterol being measured in every second participant. If participants reported not fasting prior to blood sampling, they were recorded as non-fasting. The conversion rate of 1.11 was used to convert capillary glucose to plasma glucose [27]. Glucose was measured in all participants, whilst due to resource constraints, cholesterol samples were obtained from every second participant. Age was used as a continuous variable or categorised into the following groups: 40–49, 50–59, 60–69, 70–79, and >80. Educational level was dichotomised as any completed education (primary or higher) or no completed education. Marital status was categorised as single/widowed/divorced or married/cohabiting. Wealth quintiles were derived using Filmer and Pritchetts’ method from the first principal component of household assets and construction materials [28]. Based on thresholds for individual CVDRF in use at the time of the study, having hypertension was defined as systolic blood pressure ≥ 140 or diastolic ≥ 90mmHg, calculated using the average of the final two BP readings, or being on treatment for hypertension in the past two weeks. Diabetes was defined as fasting plasma glucose (FPG) ≥7.0 mmol/L (126 mg/dL), or random plasma glucose (RPG) ≥11.1 mmol/L (200 mg/dL), or being on treatment for diabetes in the past 2 weeks. Dyslipidaemia was defined as measured total cholesterol level ≥ 6.21 mmol/L, or low-density lipoprotein (LDL) ≥ 4.1 mmol/L, or high-density lipoprotein (HDL) < 1.19 mmol/L [2, 29, 30]. Smoking was classified as current smoker if participants either reported currently smoking or had ceased within in the last year, or non-smoking. Ten-year cardiovascular disease risk was computed using the WHO-ISH equations (which were in use at the time that the survey was done) using laboratory measurements [31]. WHO-ISH scores were derived from data collected on age, sex, smoking status, diabetes status as well as cholesterol and blood pressure measurements. Patients with self-reported MI, angina or stroke were excluded from the entire analysis as our consideration was primary prevention of CVD. The methods have been described in full before [2]. Each of the 1284 public or private health facilities in Sierra Leone were included in the SARA survey [12]. The questionnaire was based upon the standard WHO SARA tool and the survey was conducted as detailed in their SARA report [17]. The questionnaires were pilot tested in facilities in the Western Area of Sierra Leone and adjusted before rolling out throughout the country. The SARA surveys capture data at each facility on presence of infrastructure and basic amenities, health workforce, service delivery and utilisation, availability of treatment guidelines, basic equipment, and treatments [12]. Data were collected by trained fieldworkers who administered the questionnaire to relevant facility staff. Data from facilities in Bo district were used for this study, to correspond to the population from which household survey data were collected. Facilities were classed as either primary or secondary care facilities (there are no tertiary hospitals in the district). Primary care clinics were Maternal and Child Health Posts (MCHP), Community Health Posts (CHP), and Community Health Centers (CHCs) [17]. Secondary care facilities were defined as district government hospitals and all other hospitals (private). Facility ownership was defined as government or private-owned. Facility readiness scores to provide care for CVDRF or HIV were derived from components required to deliver either HIV or CVDRF care. These were captured under the domains of equipment, diagnostic capacity, guidelines, medicines, and trained staff. Variables included in the initial survey were captured under the broad headings of non-communicable diseases or HIV, and as defined in the SARA manual [17, 32]. The authors further discussed variables to include or exclude from the above domains, based on clinical knowledge and experience of service provision in low resourced settings. What the different domains include is described in Appendix 1 in S1 File. For example MRI was not included as there is no MRI machine to be found in the country, and whilst it may be expected that a district level secondary hospital would have a CT scanner, this is not reasonable to expect of primary care facilities. Components included under each domain for CVDRF and HIV are shown in the S1 File. For both CVDRF and HIV, a score was created for each domain as the number of components present divided by the total number of components achievable. Scores are shown for each facility level by individual domain and inclusive of all domains. The primary outcome measure was the proportion of the study sample defined as being at high 10-year risk of having a cardiovascular event, here defined as >20% risk as done in previous studies [33]. The WHO/ISH Risk score includes age, gender, smoking, diabetes, blood pressure, cholesterol and appropriate WHO epidemiological sub region [34]. Two secondary outcomes were studied–firstly the number of people who would require treatment for any CVDRF based on the WHO-PEN guidelines (which were available in 2018). WHO-PEN guidelines recommend treatment for hypertension if BP is ≥160/90mmHg or if BP is ≥140/90mmHg and CVD risk is >20%; treatment with hypoglycaemic agents is required if there is a diagnosis of diabetes; statin and aspirin treatment should be given if there is diabetes and a 10 year risk >20%, or 10 year risk is >30%; and ACE inhibitors should be given if diabetes is present and 10 year risk >20% (Appendix 2 in S1 File). The other secondary outcome was the number of people who would require treatment for the individual risk factors of diabetes, hypertension, or dyslipidaemia as defined by the study criteria, if a treat-to-target approach were used. Other outcomes describe access to care as the proportions of participants who required treatments under WHO-PEN guidelines and who were on those treatments and facility readiness to provide care. For the household survey, a sample size of 1893 participants was required to allow detection of diabetes prevalence (the risk factor thought likely to have the lowest prevalence) of 4% with a precision of ±1% [35]. To allow for non-response and non-availability of data, we oversampled by 20%. For the SARA survey, no sampling was done and all facilities in the district were included. WHO-risk scores were calculated using generated by the WHO/ISH Risk R-package [34]. For the household survey data, probability weights for age and sex in Bo were calculated from the 2015 Population and Household Census [22], and all analyses were done using weight adjustments. Continuous data are described as mean (SD) or median (IQR) if not normally distributed. Categorical variables are described as unweighted n and weighted %. For comparisons of continuous data we used t-tests or non-parametrics tests Mann-Whitney/ANOVA if data were skewed. Multivariable analyses of categorical outcomes were done using binary logistic regression. Age was not entered into the model assessing associations with high CVD risk, given its use in calculating the risk score. We did a complete case analysis for the multivariable analysis whilst the denominator for the univariate analysis varied. All analyses were done using SPSS V.26 (IBM). Ethical approval was sought and given from the Sierra Leone Ethical and Scientific Review Committee and the BDM Research Ethics sub-committee at King’s College London (HR-17/18-7298). Consent to undertake the study was obtained from each village chief or community leader. Consent was obtained from all individuals participating in the study. In the events were participants were illiterate, the consent form was read out to them in the local language and an inked-thumb signature obtained.