Ghana Priorities: Hypertension
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In recent years, Ghana, like many other developing countries has been going through an epidemiologic transition where the proportion of deaths from non-communicable diseases is rapidly increasing, particularly cardiovascular related diseases, cancers and diabetes (IHME, 2019).
The number of persons in the population with hypertension appears to be increasing year-on-year and has become the most rapidly growing concern of the top 10 disease causes over the last decade in Ghana as further evidenced by the Ghana Health Service Facts and Figures since 2005 (GHS, 2018).
Estimates of prevalence of hypertension (systolic blood pressure of at least 140 mmHg or a diastolic blood pressure of at least 90 mmHg) is around 13 percent among men and women aged 15-49 as per the 2014 Ghanaian Demographic and Health Survey (GHDS) (Ghana Statistical Service et al. 2015). Hypertension is significantly more prevalent in urban compared to rural areas.
As part of efforts to improve detection, treatment and control of hypertension, the Ghana Health Service (GHS) together with other health Agencies of the Ministry of Health (MoH) and its development partners are piloting a few innovative strategies in some parts of the country. For example, there is the community-based hypertension management project (ComHIP) which was launched in 2015 and is being implemented in the Lower Manya Krobo municipality and seeks to bring hypertension services closer to the community by introducing blood pressure screening points in the places where people live, work and shop (Adler et al, 2019). This has been done through diverse multi-sector partnerships, for example by enabling certain local shops to offer screening (Adler et al, 2019).
The Ghana health authorities are working towards scaling the program to additional regions and integrating the ComHIP training curriculum and treatment guidelines into the national system and has the potential to avoid significant mortality and morbidity if replicated in other parts of the country and for other non-communicable diseases (Adler et al, 2019).
Intervention: Community health worker-led screening and treatment for hypertension
The intervention envisages a cadre of community health workers visiting households to screen individuals for hypertension and other cardiovascular disease risk factors. We limit the target group to those aged 30 and above since the prevalence of hypertension is relatively low at younger ages. Individuals who are assessed as having high blood pressure are referred onto a health facility for further assessment and, if deemed necessary by the medical practitioner, placed on medication.
Following the recommendations of Chalkidou, Lord and Gad (2017), we envisage that individuals are placed on diuretics in the first instance. In line with recent developments towards increased task shifting and demonstrated ability of nurses to successfully manage hypertension (Ogedegbe et al, 2018), we assume community health workers predominantly manage those with mild or moderate hypertension while physicians manage those with severe hypertension.
The analysis follows a single cohort of 12,500 men and 12,500 women who are screened in the initial year of the intervention (2018). This population size is set to approximate the average number of individuals in the target population (30 years and older) in a representative district in Ghana. The cohort is assumed to be representative of the wider population in the target age group.
Our analysis stratifies the target population into five age sub-groups (10-year increments between 30 and 69 plus one age group for all those over 70), two gender sub-groups (men and women) and four hypertension sub-groups (none/controlled, mild, moderate and severe). In total we have 40 sub-groups each with different age-gender-hypertension characteristics.
Costs and Benefits
There are two broad categories of costs – the one-off costs of screening and referral, and the ongoing costs of treatment and management.
The total costs of screening 12,500 men and 12,500 women and referring 2,536 individuals are therefore estimated at GH¢ 591,000. This cost is incurred only once at the start of the intervention timeline. This includes an estimated direct screening cost of GH¢ 330,500 for 25,000 people, an estimated time cost for 25,000 people of GH¢ 16,500 and the cost of initital referral at GH¢ 244,200 based on GH¢ 90 physician cost, GH¢ 4 for time of 1.25 hours per patient (including travel and waiting time) for 2,536 individuals – the estimated yield from screening.
The treatment costs for diuretics are drawn from Chalkidou, Lord and Gad (2017) who identify a medication cost of GH¢ 26 per person per year. In addition, costs of patient management by physicians for severe hypertension and community health workers for moderate and mild hypertension are included. For physician visits, we assume a direct cost of GH¢ 90 per visit and for community health worker visits we estimate a resource cost of GH¢ 17 per visit. Overall management and drug costs are approximately GH¢ 395,000 in the first year and decline to GH¢ 141,000 by year five of the intervention due to attrition.
The overall costs of the intervention are estimated at GH¢ 2.2 million, with two thirds attributable to case management, 27% to initial screening and 7% to the cost of diuretics themselves.
Commencing treatment should lead to a reduction in blood pressure and a reduction in the risk of hypertension related morbidity and mortality. To estimate the benefits, we use a Markov model previously created for a hypertension modelling exercise in Ghana (Chalkidou, Lord and Gad, 2017).
With a treatment regime of diuretics and 30 percent adherence after five years, the intervention is expected to avoid 29 deaths (505 life years avoided), 11.1 cases of heart disease, 0.1 cases of stroke and 1.6 heart failures. While overall health of the screened population improves, it will also lead to the onset of 1.1 cases of diabetes, relative to no intervention. These benefits are worth GH¢ 7.1 million (1.6 million USD) over ten years at an 8 percent discount rate. The costs of the intervention are GH¢ 2.18 million (0.5 million USD), resulting in an overall BCR of 3.3.
- Screening 25,000 individuals above the age of 30 for hypertension, and treating individuals with diuretics will lead to 29 deaths avoided, 11.1 cases of heart disease, 0.1 cases of stroke and 1.6 heart failures avoided over ten years assuming 30% long term adherence to treatment. These benefits are worth 7.1m GH¢ over ten years.
- The cost of the intervention are 2.2m GH¢ over ten years with two thirds coming from case management. The intervention would be less expensive if community health workers could be used instead of relatively more costly physicians.
- Screening and treatment is an effective use of resources in that benefits exceed costs by 3.3. However, other interventions in malaria, nutrition and maternal and child health are likely to yield larger benefits per unit cost. Ghana should revisit this finding when the prevalence of hypertension is larger