Drugs for preventing cardiovascular disease in China
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《英国医生杂志》
Risk factor thresholds should vary according to resources
In China cardiovascular disease accounts for a third of total mortality and the rate is still increasing.1 The disease is potentially preventable. However, the task for primary prevention targeted at risk factors is daunting given the burden of disease and sparse healthcare resources in China. The prevalence rates of hypertension, hyperlipidaemia, diabetes, overweight including obesity, and cigarette smoking in the adult population are 18.8%, 18.6%, 2.6%, 29.9%, and 36.0% respectively.2 Healthcare policies need to be evidence based, but they should also consider what the society's needs are, whether it can afford the interventions, and whether it can make cost effective use of resources.
The overall risk strategy has been widely adopted in Western populations: all risk factors in a person are considered together and the overall cardiovascular risk informs treatment decisions.3 An important message for developing countries like China is that the new strategy is more cost effective than the old practice—more cardiovascular events can be prevented by using the same amount of resources while treating the same number of patients.3 4
The new strategy calls for a large shift in conventional thinking. For example, hypertension has long been taken as a disease that needs treatment. The new strategy, however, implies that many people with hypertension may not need drug treatment while many with normal blood pressure can benefit from hypertensive drugs.3 Also contrary to conventional thinking, a lower threshold for blood pressure could be used in older people than in younger people.5 The same applies to hyperlipidaemia. This strategy may be difficult for frontline doctors in China to accept, though most doctors never read guidelines.5 6 New guidelines can take effect only when doctors and patients change their ideas, attitudes, and practice about hypertension.
Thresholds for initiating drug treatment of blood pressure, serum cholesterol, and overall cardiovascular risk require careful consideration. Since the absolute benefit from treatment continuously increases as the levels of these factors rise, any practical limits are arbitrary. A small reduction in the threshold considerably increases the number of people who need treatment. The choice of threshold is thus largely a matter of resources and social values. Countries of different economic status should recommend different thresholds. The WHO/International Society of Hypertension guidelines could result in a quarter of adults in Western countries receiving antihypertensive drugs, but this may not be feasible economically as a target for developing countries.3 The 2004 Chinese guidelines recommend similar thresholds.7 Current national guidelines on management of hyperlipidaemia state that everyone with total serum cholesterol above 6.2 mmol/l should be treated with drugs.8 These recommendations did not seem to fully consider the resources available.
China has 160 million people with hypertension and another 160 million with hyperlipidaemia. Assuming the daily cost to be ￥1 (￡0.06; $0.12; 0.09) for antihypertensive drugs and ￥2 for cholesterol lowering drugs,9 10 a conservative estimate of the total drug cost would be ￥175 billion (￡11bn; $21bn; 16bn) a year if all these patients were given drug treatment. This alone would consume almost a third of the total healthcare expenditure in the country.1 This questions the practicality of the recommendations.
In any case, most patients in China pay for treatment from their own pockets. How many hypertensive patients in poor rural areas would be willing to pay if they knew that only one in every 50-100 people treated could eventually benefit from avoiding a cardiovascular event in the next five years, at a cost of one seventh of their family's annual income? Despite many years' effort by health services in rural areas, only 5.4% of people with hypertension receive drug treatment and only 0.9% have their blood pressure effectively controlled.7 11
Research evidence on the biological efficacy of these drugs is often universally generalisable. Guidelines are, however, value laden, have cost implications, and are not universally applicable; thus those developed for one population may not suit another. As well as the thresholds for initiating treatment, factors such as treatment targets, competing priorities for drugs, diagnostic testing, and frequency of follow-up all have cost implications. The treatment target is the level of blood pressure or cholesterol to achieve through treatment—the lower the target the more resources are required to achieve it. China should probably consider targets that differ from those for Western populations.
Locally tailored treatment guidelines could further improve cost efficiency. For instance, antihypertensive drugs might be given precedence in China, particularly in the rural areas, over cholesterol lowering drugs because they are cheaper and also reduce the incidence of stroke. Stroke is common in China, and in some areas it is the leading cause of death. Each year 1.3 million people have a first stroke, four times the incidence of acute myocardial infarction.12
Given national differences in epidemiology, local needs, and affordability, developing countries such as China need to tailor their national policies for managing chronic conditions. If policies for other populations are used, adapting, rather than simply adopting, will bring greater benefits to patients.
Jin Ling Tang, director
Chinese Cochrane Centre Hong Kong Branch, Faculty of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR, China (jltang@cuhk.edu.hk)
Yong Hua Hu, professor
Peking University Centre for Evidence-Based Medicine, School of Public Health, Peking University Health Sciences Centre, 38 Xue Yuan Road, Haidian District, Beijing 100083, China
Competing interests: None declared.
References
Ministry of Health. Summary of 2004 Health Statistics of China. 21 May 2004. www.moh.gov.cn/public/open.aspx?n_id=8006&seq=0 (accessed 8 Mar 2005).
Zhang F. Assessing the health status of the nation. China Daily 2004 Oct 12. www.chinadaily.com.cn/english/doc/2004-10/12/content_381680.htm (accessed 8 Mar 2005).
World Health Organization, International Society of Hypertension Writing Group. 2003 World Health Organization (WHO)/International Society of Hypertension (ISH) statement on management of hypertension. J Hypertens 2003;21: 1983-92.
Baker S, Priest P, Jackson R. Using thresholds based on risk of cardiovascular disease to target treatment for hypertension: modelling events averted and number treated. BMJ 2000;320: 680-5.
Dickerson JEC, Brown MJ. Influence of age on general practitioners' definition and treatment of hypertension. BMJ 1995;309: 574.
Cheng YZ, Wu XG, Huang W, Qi GQ, Gu DF. Physicians' awareness of "the guidelines for prevention and treatment of hypertension in China." Chin J Hypertens 2002;10: 176-7.
Revision Committee of the Chinese guidelines on prevention and treatment of hypertension. 2004 Chinese guidelines on prevention and treatment of hypertension. Chin J Hypertens 2004;12: 483-6.
Fang Q, Wang ZL, Ning TH, Shao G, Chen ZJ, Lu ZL, et al. Recommendations for prevention and management of dyslipidemia. Chin J Cadiovasc Dis 1997;25: 169-75.
Chen Y, Wang M, Zhan SY, Liu KJ, Sun Q, Chen WH, et al. Analysis of costs in outpatients with hypertension in Shanghai. Chin J Epidemiol 2003;24: 1074-7.
Chen QY, Wei SY, Lu XH. Comparison of zhibituo and lovastatin in treatment of hyperlipidemia. J Med Postgraduates 2004;17: 233-5.
Ministry of Health. Nutrition and health status of the Chinese population. 12 Oct 2004. www.moh.gov.cn/public/open.aspx?n_id=8646&seq=0 (accessed 8 Mar 2005).
American Heart Association. China. www.americanheart.org/presenter.jhtml?identifier=2572 (accessed 8 March 2005).
In China cardiovascular disease accounts for a third of total mortality and the rate is still increasing.1 The disease is potentially preventable. However, the task for primary prevention targeted at risk factors is daunting given the burden of disease and sparse healthcare resources in China. The prevalence rates of hypertension, hyperlipidaemia, diabetes, overweight including obesity, and cigarette smoking in the adult population are 18.8%, 18.6%, 2.6%, 29.9%, and 36.0% respectively.2 Healthcare policies need to be evidence based, but they should also consider what the society's needs are, whether it can afford the interventions, and whether it can make cost effective use of resources.
The overall risk strategy has been widely adopted in Western populations: all risk factors in a person are considered together and the overall cardiovascular risk informs treatment decisions.3 An important message for developing countries like China is that the new strategy is more cost effective than the old practice—more cardiovascular events can be prevented by using the same amount of resources while treating the same number of patients.3 4
The new strategy calls for a large shift in conventional thinking. For example, hypertension has long been taken as a disease that needs treatment. The new strategy, however, implies that many people with hypertension may not need drug treatment while many with normal blood pressure can benefit from hypertensive drugs.3 Also contrary to conventional thinking, a lower threshold for blood pressure could be used in older people than in younger people.5 The same applies to hyperlipidaemia. This strategy may be difficult for frontline doctors in China to accept, though most doctors never read guidelines.5 6 New guidelines can take effect only when doctors and patients change their ideas, attitudes, and practice about hypertension.
Thresholds for initiating drug treatment of blood pressure, serum cholesterol, and overall cardiovascular risk require careful consideration. Since the absolute benefit from treatment continuously increases as the levels of these factors rise, any practical limits are arbitrary. A small reduction in the threshold considerably increases the number of people who need treatment. The choice of threshold is thus largely a matter of resources and social values. Countries of different economic status should recommend different thresholds. The WHO/International Society of Hypertension guidelines could result in a quarter of adults in Western countries receiving antihypertensive drugs, but this may not be feasible economically as a target for developing countries.3 The 2004 Chinese guidelines recommend similar thresholds.7 Current national guidelines on management of hyperlipidaemia state that everyone with total serum cholesterol above 6.2 mmol/l should be treated with drugs.8 These recommendations did not seem to fully consider the resources available.
China has 160 million people with hypertension and another 160 million with hyperlipidaemia. Assuming the daily cost to be ￥1 (￡0.06; $0.12; 0.09) for antihypertensive drugs and ￥2 for cholesterol lowering drugs,9 10 a conservative estimate of the total drug cost would be ￥175 billion (￡11bn; $21bn; 16bn) a year if all these patients were given drug treatment. This alone would consume almost a third of the total healthcare expenditure in the country.1 This questions the practicality of the recommendations.
In any case, most patients in China pay for treatment from their own pockets. How many hypertensive patients in poor rural areas would be willing to pay if they knew that only one in every 50-100 people treated could eventually benefit from avoiding a cardiovascular event in the next five years, at a cost of one seventh of their family's annual income? Despite many years' effort by health services in rural areas, only 5.4% of people with hypertension receive drug treatment and only 0.9% have their blood pressure effectively controlled.7 11
Research evidence on the biological efficacy of these drugs is often universally generalisable. Guidelines are, however, value laden, have cost implications, and are not universally applicable; thus those developed for one population may not suit another. As well as the thresholds for initiating treatment, factors such as treatment targets, competing priorities for drugs, diagnostic testing, and frequency of follow-up all have cost implications. The treatment target is the level of blood pressure or cholesterol to achieve through treatment—the lower the target the more resources are required to achieve it. China should probably consider targets that differ from those for Western populations.
Locally tailored treatment guidelines could further improve cost efficiency. For instance, antihypertensive drugs might be given precedence in China, particularly in the rural areas, over cholesterol lowering drugs because they are cheaper and also reduce the incidence of stroke. Stroke is common in China, and in some areas it is the leading cause of death. Each year 1.3 million people have a first stroke, four times the incidence of acute myocardial infarction.12
Given national differences in epidemiology, local needs, and affordability, developing countries such as China need to tailor their national policies for managing chronic conditions. If policies for other populations are used, adapting, rather than simply adopting, will bring greater benefits to patients.
Jin Ling Tang, director
Chinese Cochrane Centre Hong Kong Branch, Faculty of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR, China (jltang@cuhk.edu.hk)
Yong Hua Hu, professor
Peking University Centre for Evidence-Based Medicine, School of Public Health, Peking University Health Sciences Centre, 38 Xue Yuan Road, Haidian District, Beijing 100083, China
Competing interests: None declared.
References
Ministry of Health. Summary of 2004 Health Statistics of China. 21 May 2004. www.moh.gov.cn/public/open.aspx?n_id=8006&seq=0 (accessed 8 Mar 2005).
Zhang F. Assessing the health status of the nation. China Daily 2004 Oct 12. www.chinadaily.com.cn/english/doc/2004-10/12/content_381680.htm (accessed 8 Mar 2005).
World Health Organization, International Society of Hypertension Writing Group. 2003 World Health Organization (WHO)/International Society of Hypertension (ISH) statement on management of hypertension. J Hypertens 2003;21: 1983-92.
Baker S, Priest P, Jackson R. Using thresholds based on risk of cardiovascular disease to target treatment for hypertension: modelling events averted and number treated. BMJ 2000;320: 680-5.
Dickerson JEC, Brown MJ. Influence of age on general practitioners' definition and treatment of hypertension. BMJ 1995;309: 574.
Cheng YZ, Wu XG, Huang W, Qi GQ, Gu DF. Physicians' awareness of "the guidelines for prevention and treatment of hypertension in China." Chin J Hypertens 2002;10: 176-7.
Revision Committee of the Chinese guidelines on prevention and treatment of hypertension. 2004 Chinese guidelines on prevention and treatment of hypertension. Chin J Hypertens 2004;12: 483-6.
Fang Q, Wang ZL, Ning TH, Shao G, Chen ZJ, Lu ZL, et al. Recommendations for prevention and management of dyslipidemia. Chin J Cadiovasc Dis 1997;25: 169-75.
Chen Y, Wang M, Zhan SY, Liu KJ, Sun Q, Chen WH, et al. Analysis of costs in outpatients with hypertension in Shanghai. Chin J Epidemiol 2003;24: 1074-7.
Chen QY, Wei SY, Lu XH. Comparison of zhibituo and lovastatin in treatment of hyperlipidemia. J Med Postgraduates 2004;17: 233-5.
Ministry of Health. Nutrition and health status of the Chinese population. 12 Oct 2004. www.moh.gov.cn/public/open.aspx?n_id=8646&seq=0 (accessed 8 Mar 2005).
American Heart Association. China. www.americanheart.org/presenter.jhtml?identifier=2572 (accessed 8 March 2005).