Exposure to cardiovascular risk factors like hypertension is increasing in low- and middle-income countries, and availability and use of medications to prevent and treat cardiovascular disease remain incredibly low, particularly in the poorest countries.1,2 At the same time, the 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults3 lowers the bar for diagnosis of hypertension in wealthy countries, a shift that in any country would have the inevitable effect of categorizing more people as hypertensive and initiating drug therapy for these patients. Kibria and colleagues4 present a secondary analysis of the 2016 Nepal Demographic and Health Survey that estimated the prevalence of hypertension in Nepal, comparing this new hypertension guideline with the widely used Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guideline. The study found that if the ACC/AHA guideline was used, the overall prevalence of hypertension in Nepal would approximately double (from 21.2% to 44.2%), mostly by shifting more individuals out of the normal and prehypertension categories. Importantly, the study also found that the prevalence of stage 2 hypertension more than doubled (from 6.6% to 19.0%), suggesting that the number of individuals requiring pharmacotherapy would greatly increase if the new guideline was to be implemented.
The study by Kibria and colleagues adds to the literature documenting the high prevalence of hypertension among adults in low- and middle-income countries. Prevalence estimates of about 20% in Nepal (according to the JNC 7 definition) are broadly consistent with, although a bit lower than, the global age-standardized estimates of 28% reported recently in the Prospective Urban Rural Epidemiology (PURE) study.2 The difference could be due to several factors, including Nepal’s predominantly rural population, relatively young population structure, and low income, all of which correlated with lower hypertension prevalence among PURE study countries. Notably, the prevalence of hypertension among the wealthiest fifth of the Nepalese population was significantly higher than the rest of the population, suggesting that risk factor exposure patterns (eg, diet and physical activity) may be different in this group.
More importantly, though, this study raises important questions about allocation of scarce resources to treatment of hypertension in low-income countries, particularly as cardiovascular interventions continue to become more sophisticated (and more widely available) and clinical standards continue to move in favor of medicalization. Lowering the threshold for diagnosis of hypertension, as recommended in the new ACC/AHA guideline, could be considered a laudable move in light of accumulating evidence that increased blood pressure is associated with adverse cardiovascular outcomes at levels of blood pressure below 140/80 mm Hg. Conversely, a lower threshold could inject confusion into the cardiovascular disease policy agenda in settings with limited resources.
Debates around the relative value for money in managing cardiovascular risk have largely been resolved through a body of literature describing studies conducted in different low- and middle-income country settings.5 Modeling studies generally agree that focusing on blood pressure treatment among the subset of individuals with the highest level of cardiovascular risk is likely to yield the best overall outcomes for a given budget.6,7 The general relationship between health investments in cardiovascular prevention (in different subsets of the population at different levels of cardiovascular risk) illustrates the principle of diminishing marginal returns (Figure).
Figure. Theoretical Diminishing Marginal Returns With Expansion of Cardiovascular (CV) Care Treatment to Groups at Lower Absolute Risk of Cardiovascular Death
The graph shows the diminishing marginal returns of treating different subsets of the population at different levels of cardiovascular risk. IHD indicates ischemic heart disease.
A progressive approach to universal health coverage implies that, at a given budget level, countries should begin by ensuring full population coverage of health services that provide the highest value for money, even if this means that fewer services are initially available.8 In the case of cardiovascular disease, this would often mean focusing on identifying existing and new cases of ischemic heart disease and stroke and providing medical therapy (secondary prevention), and perhaps providing treatment for individuals with hypertension who have a high absolute 10-year risk of cardiovascular disease (eg, older persons, males, tobacco users, and individuals with diabetes). As resources allow, expansion of hypertension treatment to lower-risk segments of the population would be reasonable, so long as the more cost-effective services have already been rolled out to the entire population.
Although antihypertensive drugs are relatively inexpensive, the impact of a shift from JNC 7 to the 2017 ACC/AHA guideline could be incredibly costly in Nepal, especially when these additional resources would have to come at the expense of scaling up highly effective programs for other noncommunicable and infectious diseases. Unfortunately, limitations of the Nepal Demographic and Health Survey data set did not allow the authors of this study to estimate the additional number of persons who would require pharmacotherapy for hypertension. Such an exercise, which would ideally include an estimate of the additional cost and number of lives saved by using the ACC/AHA guideline, would be critical in deciding whether to apply it locally.
It should be emphasized that rationing hypertension treatment does not imply turning a blind eye to the problem. A number of effective population-level intersectoral policies can be implemented at very low cost, even in settings where health system capacity is low.9 These policies include taxation of tobacco and alcohol products and regulatory actions to reduce the sodium content in processed foods. Population-level policies do require significant bureaucratic capabilities and coordination across ministries of government, but they may be relatively more attractive to finance ministers compared with new health system investments, especially if they generate new revenues.
Finally, it should be remembered that the publication of the 2017 ACC/AHA guideline will not settle the scientific debate around the definition and appropriate treatment of hypertension. As new evidence accumulates, the pendulum may swing away from medicalization, as has occurred recently on the matter of hypertension in older adults.10 For now, the main implication of the study by Kibria and colleagues for public health in Nepal and other low-income countries might be to approach the ACC/AHA guideline with caution, particularly because it has such far-reaching consequences for primary health care systems that are already overburdened.
Published: July 13, 2018. doi:10.1001/jamanetworkopen.2018.0778
Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2018 Watkins DA. JAMA Network Open.
Corresponding Author: David A. Watkins, MD, MPH, Division of General Internal Medicine, Department of Medicine, University of Washington, 325 Ninth Ave, PO Box 359780, Seattle, WA 98104 (email@example.com).
Conflict of Interest Disclosures: Dr Watkins reports grants from Bill and Melinda Gates Foundation outside the submitted work.
et al; Prospective Urban Rural Epidemiology (PURE) Study Investigators. Use of secondary prevention drugs for cardiovascular disease in the community in high-income, middle-income, and low-income countries (the PURE Study): a prospective epidemiological survey. Lancet
. 2011;378(9798):1231-1243. doi:10.1016/S0140-6736(11)61215-4PubMedGoogle ScholarCrossref
et al; PURE (Prospective Urban Rural Epidemiology) Study Investigators. Prevalence, awareness, treatment, and control of hypertension in rural and urban communities in high-, middle-, and low-income countries. JAMA
. 2013;310(9):959-968. doi:10.1001/jama.2013.184182PubMedGoogle ScholarCrossref
et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension
. 2018;71(6):e13-e115. doi:10.1161/HYP.0000000000000065PubMedGoogle Scholar
et al; Disease Control Priorities-3 Cardiovascular, Respiratory, and Related Disorders Author Group. Cardiovascular, respiratory, and related disorders: key messages from Disease Control Priorities, 3rd edition. Lancet
. 2018;391(10126):1224-1236. doi:10.1016/S0140-6736(17)32471-6PubMedGoogle ScholarCrossref
S. Cost effectiveness of strategies to combat cardiovascular disease, diabetes, and tobacco use in sub-Saharan Africa and South East Asia: mathematical modelling study. BMJ
. 2012;344:e607. doi:10.1136/bmj.e607PubMedGoogle ScholarCrossref
World Health Organization. Making Fair Choices on the Path to Universal Health Coverage. Final Report of the WHO Consultative Group on Equity and Universal Health Coverage. Geneva, Switzerland: World Health Organization; 2014.
et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA
. 2014;311(5):507-520. doi:10.1001/jama.2013.284427PubMedGoogle ScholarCrossref