Blood pressure control: a challenge to global health systems

Raised blood pressure is the most important risk factor in the global burden of disease.1GBD 2017 Risk Factor CollaboratorsGlobal, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017.Lancet. 2018; 392: 1923-1994PubMed Scopus (2423) Google Scholar Although there is robust evidence to show that lowering blood pressure can substantially reduce cardiovascular morbidity and mortality,2Ettehad D Emdin CA Kiran A et al.Blood pressure lowering for prevention of cardiovascular disease and death: a systematic review and meta-analysis.Lancet. 2016; 387: 957-967Summary Full Text Full Text PDF PubMed Scopus (1878) Google Scholar the global burden of hypertension is increasing.3NCD Risk Factor Collaboration (NCD-RisC)Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19·1 million participants.Lancet. 2017; 389: 37-55Summary Full Text Full Text PDF PubMed Scopus (1316) Google Scholar, 4Forouzanfar MH Liu P Roth GA et al.Global burden of hypertension and systolic blood pressure of at least 110 to 115 mm Hg, 1990–2015.JAMA. 2017; 317: 165-182Crossref PubMed Scopus (1153) Google Scholar To achieve a reduction in the burden of disease related to hypertension, health systems must ensure that high blood pressure treatment and control rates are achieved. The status of controlled blood pressure is being promoted as a measure of universal health coverage, especially in the context of non-communicable diseases. Achieving universal health coverage is a target of the UN Sustainable Development Goals.5Hogan DR Stevens GA Hosseinpoor AR Boerma T Monitoring universal health coverage within the Sustainable Development Goals: development and baseline data for an index of essential health services.Lancet Glob Health. 2018; 6: e152-e168Summary Full Text Full Text PDF PubMed Scopus (188) Google Scholar Few studies have compared the awareness, treatment, and control of hypertension across countries. The Prospective Urban Rural Epidemiology (PURE) study6Chow CK Teo KK Rangarajan S et al.Prevalence, awareness, treatment, and control of hypertension in rural and urban communities in high-, middle-, and low-income countries.JAMA. 2013; 310: 959-968Crossref PubMed Scopus (1167) Google Scholar reported findings from 142 042 participants aged 35–70 years from three high-income countries (HICs), seven upper-middle-income countries (UMICs), and seven low-income countries and lower-middle-income countries. This study found that 57 840 (40·8%) participants had hypertension, 26 877 (46·5%) of those with hypertension were aware of their condition, 23 510 (40·6%) participants (87·5% of those who were aware of their condition) were receiving treatment, and hypertension was controlled in 7634 (13·2%) participants (32·5% of those being treated). Overall control was worst in low-income and lower-middle-income countries (10·8%), compared with 19% in HICs and 15·6% in UMICs. Some reasons for the low frequency of treatment and control of hypertension were identified, which included insufficient therapy and poor access.7Attaei MW Khatib R McKee M et al.Availability and affordability of blood pressure-lowering medicines and the effect on blood pressure control in high-income, middle-income, and low-income countries: an analysis of the PURE study data.Lancet Public Health. 2017; 2: e411-e419Summary Full Text Full Text PDF PubMed Scopus (104) Google Scholar Data on the prevalence, awareness, treatment, and control of hypertension are described in two Articles in The Lancet. The NCD Risk Factor Collaboration (NCD-RisC)8NCD Risk Factor Collaboration (NCD-RisC)Long-term and recent trends in hypertension awareness, treatment and control in 12 high-income countries: an analysis of 123 nationally representative surveys.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)31145-6Google Scholar evaluated trends from 1976 to 2017 in 526 336 participants aged 40–79 years from 12 HICs by use of 123 national health examination surveys. The study reported increases in awareness, treatment, and control of hypertension over time, but it also suggested that the frequency of treatment and control has plateaued. The main limitation of their analysis was data availability: only two data sources each for Germany and Ireland; fewer than ten data sources each for Australia, Canada, Finland, Italy, New Zealand, and Spain; 11 data sources for the USA; 13 data sources for South Korea; 25 data sources for the UK; and 31 data sources for Japan were available. Pascal Geldsetzer and colleagues9Geldsetzer P Manne-Goehler J Marcus ME et al.The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adults.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)30955-9Summary Full Text Full Text PDF PubMed Scopus (195) Google Scholar reported data from 1·1 million participants from 44 low-income and middle-income countries (LMICs; 2005–16): they found that 17·5% of these individuals had hypertension and that, among those with hypertension, 39·2% were aware of their diagnosis, 29·9% had received treatment, and 10·3% had control of their hypertension. The authors uniquely converted these data into a cascade of hypertension care as a measure of performance of health systems. They reported very low hypertension control and highlighted the LMICs achieving control of blood pressure in less than 5% of patients with hypertension, including ten of 16 countries in sub-Saharan Africa, three of eight countries in southeast Asia and the western Pacific, and one of ten countries in Europe and the eastern Mediterranean. The authors noted that, although lower gross domestic product has been linked to poor performance, some countries (such as Costa Rica, Kyrgyzstan, and Bangladesh) have performed better than expected relative to their gross domestic product.9Geldsetzer P Manne-Goehler J Marcus ME et al.The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adults.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)30955-9Summary Full Text Full Text PDF PubMed Scopus (195) Google Scholar They also reported that older age, an individual being female or a non-smoker, and higher levels of education and income were associated with higher progression through the cascade of care. The findings by Geldsetzer and colleagues are similar to those of studies10Gupta R Gaur K Ram CVS Emerging trends in hypertension epidemiology in India.J Hum Hypertens. 2018; (published online Sept 25.)DOI:10.1038/s41371-018-0117-3Crossref PubMed Scopus (95) Google Scholar, 11Lu J Lu Y Wang X et al.Prevalence, awareness, treatment, and control of hypertension in China: data from 1·7 million adults in a population-based screening study (China PEACE Million Persons Project).Lancet. 2017; 390: 2549-2558Summary Full Text Full Text PDF PubMed Scopus (567) Google Scholar from India and China. Interpretation and comparison of data on hypertension epidemiology are challenging and combining several studies, as has been done by the two groups, might not be the best method for cross-country comparisons. There are well known variations in methods of blood pressure measurement,12Myers MG Godwin M Dawes M et al.Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial.BMJ. 2011; 342: d286Crossref PubMed Scopus (221) Google Scholar and differences across studies in their definitions of hypertension, including blood pressure cutoffs and how self-reported data are incorporated. Differences might also be due to variations in local hypertension guidelines. The effect of age demography should also be considered. These factors mean that tracking trends over time and comparing them across countries is difficult and, although some factors can be accounted for, as has been done in the pooled studies of the NCD-RisC group8NCD Risk Factor Collaboration (NCD-RisC)Long-term and recent trends in hypertension awareness, treatment and control in 12 high-income countries: an analysis of 123 nationally representative surveys.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)31145-6Google Scholar and Geldsetzer and colleagues,9Geldsetzer P Manne-Goehler J Marcus ME et al.The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adults.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)30955-9Summary Full Text Full Text PDF PubMed Scopus (195) Google Scholar these adjustments do not remove the inherent variability that occur due to unmeasured differences in the implementation of several different study protocols. The model of multicountry studies applying a universal protocol, such as in the PURE study,13Teo K Chow CK Vaz M Rangarajan S Yusuf S on behalf of the PURE Investigators-Writing GroupThe Prospective Urban Rural Epidemiology (PURE) study: examining the impact of societal influences on chronic noncommunicable diseases in low-, middle-, and high-income countries.Am Heart J. 2009; 158: 1-7Crossref PubMed Scopus (396) Google Scholar could be useful because the same rules on measurement and definitions across countries can be used. However, unlike the nationally representative studies collated in these Articles,8NCD Risk Factor Collaboration (NCD-RisC)Long-term and recent trends in hypertension awareness, treatment and control in 12 high-income countries: an analysis of 123 nationally representative surveys.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)31145-6Google Scholar, 9Geldsetzer P Manne-Goehler J Marcus ME et al.The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adults.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)30955-9Summary Full Text Full Text PDF PubMed Scopus (195) Google Scholar the PURE study was not nationally representative. International cooperation to obtain nationally representative samples with similar methods is needed. There are several reasons for poor control of blood pressure, and these reasons differ, including in importance, between HICs and LMICs. The factors involved range from social determinants (such as rapid and unplanned urbanisation, poverty, illiteracy, the political context, gender and racial discrimination, the human development index, and social development); to factors relating to health care (infrastructure, availability, access, and quality), medical education (the number of physicians, nurses, and paramedical workers), and physicians (competing interests, information overload, and inertia); to patient adherence. As demonstrated by the two studies,8NCD Risk Factor Collaboration (NCD-RisC)Long-term and recent trends in hypertension awareness, treatment and control in 12 high-income countries: an analysis of 123 nationally representative surveys.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)31145-6Google Scholar, 9Geldsetzer P Manne-Goehler J Marcus ME et al.The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adults.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)30955-9Summary Full Text Full Text PDF PubMed Scopus (195) Google Scholar there are large inequities between countries, and cross-country comparisons, particularly in LMICs, highlight how far some countries are from achieving the UN Sustainable Development Goal of universal health coverage. These studies do not elucidate the specific barriers to and enabling factors in hypertension care. Future studies could examine the interplay of the factors that affect control of blood pressure and identify those that are modifiable. Although some factors might be common to countries of similar economic development, there could be common factors acting at a health system level that could improve control of blood pressure in both HICs and LMICs and that could be discovered by use of measures to link the health system to pooled data on control of blood pressure. Additionally, qualitative and detailed case studies could unpack the mechanisms underlying high and low performance of health-care systems. For example, the study by Geldsetzer and colleagues postulates the reasons for the better performance of some countries relative to others, including strong primary health care, better community health worker infrastructure, and easy availability and affordability of antihypertensive medications in these countries, but such factors could be researched systematically across countries. Although the study by NCD-RisC8NCD Risk Factor Collaboration (NCD-RisC)Long-term and recent trends in hypertension awareness, treatment and control in 12 high-income countries: an analysis of 123 nationally representative surveys.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)31145-6Google Scholar indicates hope for improving trends in hypertension care in HICs, it also highlights that, at best, only 50–60% of those with hypertension have controlled blood pressure, and it suggests there might be an upper limit to the control of blood pressure that is achievable. In HICs, availability and affordability of medication are less likely to be a barrier to effective control of blood pressure, but better strategies to address physician inertia or medical patient adherence might be needed. Perhaps more effective therapeutics or simpler ways of administering combination therapy are required, as embodied by the quadpill: a single pill containing several ultra-low-dose pills.14Chow CK Thakkar J Bennett A et al.Quarter-dose quadruple combination therapy for initial treatment of hypertension: placebo-controlled, crossover, randomised trial and systematic review.Lancet. 2017; 389: 1035-1042Summary Full Text Full Text PDF PubMed Scopus (76) Google Scholar More innovation in implementation and evaluation of interventions is needed. Although there are substantial data on the hypertension-related performance of health systems in these studies8NCD Risk Factor Collaboration (NCD-RisC)Long-term and recent trends in hypertension awareness, treatment and control in 12 high-income countries: an analysis of 123 nationally representative surveys.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)31145-6Google Scholar, 9Geldsetzer P Manne-Goehler J Marcus ME et al.The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adults.Lancet. 2019; (published online July 18.)http://dx.doi.org/10.1016/S0140-6736(19)30955-9Summary Full Text Full Text PDF PubMed Scopus (195) Google Scholar in HICs and LMICs that highlight the substantial gaps and inequities, more data are needed to understand the reasons for poor performance and variability of performance. These studies also highlight that the global problem of control of blood pressure is far from fixed. Indeed, they highlight how dire this issue is in some LMICs where control of blood pressure is achieved in less than 5% of individuals with hypertension. Both HICs and low-income countries require innovative interventions to more effectively treat blood pressure and support health systems to address the massive burden of high blood pressure. We need more detailed and more systematic research into why we are failing to achieve control of blood pressure. CKC reports a career development fellowship from the National Health and Medical Research Council of Australia and the National Heart Foundation, outside of the work submitted here. RG declares no competing interests. The state of hypertension care in 44 low-income and middle-income countries: a cross-sectional study of nationally representative individual-level data from 1·1 million adultsOur study provides important evidence for the design and targeting of health policies and service interventions for hypertension in LMICs. We show at what steps and for whom there are gaps in the hypertension care process in each of the 44 countries in our study. We also identified countries in each world region that perform better than expected from their economic development, which can direct policy makers to important policy lessons. Given the high disease burden caused by hypertension in LMICs, nationally representative hypertension care cascades, as constructed in this study, are an important measure of progress towards achieving universal health coverage. Full-Text PDF Long-term and recent trends in hypertension awareness, treatment, and control in 12 high-income countries: an analysis of 123 nationally representative surveysHypertension awareness, treatment, and control have improved substantially in high-income countries since the 1980s and 1990s. However, control rates have plateaued in the past decade, at levels lower than those in high-quality hypertension programmes. There is substantial variation across countries in the rates of hypertension awareness, treatment, and control.