Conclusions: In the same number of people treated, the number of CVD events avoided for the overall risk approach is always larger than that of the blood pressure approach. The additional benefits of overall risk approach compared with the blood pressure approach decreases as the percentage of people from the total population is increased. If the current practice and hypertension guidelines in China are shifted to the overall risk approach, many more CVD events could be avoided with the same resources used. / Methods: The sample used in the analyses includes a subsample of 38,673 persons from the 2002 China National Nutrition and Health Survey, who were 30-74 years old, without previous CVD, and had data on all major CVD risk factors. CVD risks of the patients selected by each approach are predicted using suitable risk prediction equation. The RRR of anti-hypertensive drug treatment derived from meta-analyses of RCTs. The difference in the absolute effectiveness between the two approaches is used to quantify how many more CVD events can be prevented in 1000 people treated by the ORA as compared to the BPA. / Objective: To estimate and compare the number of major cardiovascular events that could be avoided by shifting the blood pressure approach to the overall risk approach if the same percentage of people in a large, representative Chinese population is treated with anti-hypertensive drugs. / Results: When 2.5%, 5.5%, 10.1%, 15.5%, 20.7%, 25.7% or 33.0% of the 38,673 subjects were treated by anti-hypertensive drugs by using the two approaches respectively, 22 (95%CI: 17∼28), 13 (11∼16), 9 (8∼10), 7 (6∼8), 6 (5∼7), 5 (4∼6), or 4 (3∼4) more CVD events could be avoided in every 1000 people treated if the blood pressure approach is shifted to the overall risk approach, which is in general a 15% to 25% increase in CVD events prevented. / Qin, Ying. / Adviser: Jin Ling Tang. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 116-121). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

After adjusted for the effect of baseline MCE risk and reduction in SBP, the multivariate meta-regression showed baseline SBP was not significantly related to the RD for all the relevant outcomes examined (p>0.22) except MCE (p=0.0226). However, the baseline MCE risk remained significantly related to the RD for all the outcomes (p<0.01) except CHD (p=0.1011). The reduction in SBP remained significantly related to the RD for deaths due to CVD, MCE, CHF and stroke (p<0.01) but not to the RD for all-cause death (p=0.3788) and CHD (p=0.8755). / Conclusions. This study showed that baseline CVD risk and reduction in blood pressure were strongly and consistently related to the absolute effect of treatment and surprisingly the baseline blood pressure was not. The findings lend direct support to the overall risk approach to primary prevention and suggest that contrary to conventional wisdom and current practice, the overall CVD risk rather than blood pressure alone should be used to identify and treat people to prevent major CVD events through anti-hypertensive drugs. These findings suggest that anti-hypertensive drugs should be given to those who have a high future CVD risk rather than high blood pressure alone so as to achieve better cost-effectiveness of anti-hypertensive drugs for primary prevention. / Data extraction and analyses: Two reviewers independently abstracted data on baseline variables, variables that determine methodological quality, and outcomes. The following main outcomes were assessed: all-cause deaths, deaths due to cardiovascular disease, death due to causes other than CVD, major cardiovascular events (MCE), congestive heart failure (CHF), stroke, and coronary heart disease (CHD). / Key words. hypertension, antihypertensive drugs, cardiovascular disease, meta-analysis, systematic review, randomized controlled trial, primary prevention, baseline risk, evidence based medicine / Meta-analysis was used to obtain the overall odds ratio (OR) and risk difference (RD). Forest plots, bubble plots and funnel plots were used to show the results visually or to check biases. Meta-regression was used to identify factors that may independently determine the effect of antihypertensive drugs. The control CVD risk, initial mean blood pressure and reduction in blood pressure were examined. / Method. Identification of studies: The databases searched included ACP Journal Club, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Cumulative Index to Nursing & Allied Health Literature, Chinese Medical Current Contents to identify relevant studies between 1966 and 2005. We also examined references from relevant trials, reviews and meta-analyses. For trials to be included in this review, they have to have the following characteristics: (1) essential hypertension in patients of any age, sex and race; (2) treatment intervention is antihypertensive drugs; (3) control intervention is a placebo or no treatment; (4) endpoint outcomes are all-cause death and major cardiovascular events; and (5) randomized controlled trials. / Objective. Although the overall risk approach to cardiovascular disease (CVD) primary prevention has been widely adopted, direct evidence that supports this policy is however weak and in some aspects lacking. Importantly, there is no direct evidence to show, between blood pressure and CVD risk, which is a better predictor of the absolute benefit from anti-hypertensive drugs. The evidence that the absolute benefit increases as the future CVD risk increases does not necessarily mean that treating high risk people will be more cost-effective than treating hypertensive people as blood pressure may also be positively related to treatment benefit. The high risk approach would be preferable only when we can show with strong evidence that blood pressure is not related to the absolute benefit of treatment or the CVD risk is much more strongly related to the benefit than blood pressure. We thus conducted this systematic review to examine the evidence from randomized controlled trials to directly show how blood pressure and CVD risk are related to the absolute benefit from anti-hypertensive drugs and compare the capability of the two factors in predicting the benefit. The stronger predictor should be a better indicator for identifying those who should be treated with anti-hypertensive drugs. / Results. Twenty-two eligible randomized controlled trials with a total of 55,448 participants were identified from 1967 to 2004. The average follow-up was 45.6 months ranging from 13 to 84 months. The combined RD and OR for all-cause deaths, deaths due to CVD, MCE, CHF, Stroke and CHD were all statistically significant, showing a consistent and considerable reduction in the risk of these outcomes due to the treatment of anti-hypertensive drugs (p<0.01). / Jiang, Yu. / "September 2007." / Adviser: Jin Ling Tang. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4657. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 107-115). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Conclusions. Regardless the method the information on benefit was provided, the maximum amount of money which people are willing to pay for antihypertensive varied substantially. Using relative risk to present the benefit would distort the viewpoint of the public regarding the importance of drug treatment. Residents were much more conservative in antihypertensive drugs than physicians. Most hypertensive patients in China would probably not accept drugs treatment for primary prevention if they are adequately informed. Rural residents were on average, less willing to take antihypertensive drugs than urban residents. Residents had a poor perception of their cardiovascular risk due to hypertension and the benefit of drug treatment. Most physicians in our study did not have good knowledge on overall risk approach and Chinese national guidelines. They had also very poor knowledge and skills related to evidence based medicine. (Abstract shortened by UMI.) / Objective. To assess the maximum amount of money residents are willing to pay for antihypertensive drugs given the actual benefit of treatment. To decide the minimum benefit (expressed in NNT) above which people are willing to pay for antihypertensive drugs at the current cost. To determine the minimum risk of cardiovascular disease (CVD) above which people would be willing to pay for antihypertensive at the current cost. To assess whether reporting of study results by using relative risk reduction and NNT affects people's willingness to pay for and physicians' willingness to prescribe antihypertensive drugs. To evaluate patients' and physicians' perception of perceived CVD risk due to hypertension and benefit of treatment. To assess knowledge, attitude and perception of the public and physicians regarding antihypertensive drugs and physicians' knowledge and skills on evidence based medicine. / Results. The response rate for residents was 91%. 95% of respondents reported that they would be willing to take antihypertensive drugs if they found to have high blood pressure. The majority of residents did not know the ultimate goal of blood pressure lowering was to reduce the risk of CVD. 91% said that they had not enough knowledge and information to make drug-taking decisions. The perceived 5-year baseline risk in the absence of treatment, absolute risk reduction and relative risk reduction was 70%, 40% and 60% respectively. Rural residents tended to over-rate their risk and benefit more than urban residents. Overall, 2%, 3% and 47% of residents were not willing to pay anything for antihypertensive drugs when information on benefit of treatment was described in general, with RRR and with NNT respectively. The median cost the residents were willing to pay was $500, $700 and $100 respectively for responding three ways of describing the benefit. / The response rate for physicians was 95%. The perceived 5-year baseline risk, absolute risk reduction and relative risk reduction was 40%, 20% and 39% respectively. Internists tended to give a slightly higher estimate of the 5-year risk (40% vs 30%, p<0.05) and of the RRR (39 vs 29, p<0.05). Overall, physicians were more likely to prescribe antihypertensive drugs when the benefit information was expressed in RRR than when it was expressed in NNT (p<0.001). The median minimum NNT and the 5-year CVD risk above which physicians are willing to prescribe was 200 and 1.5% respectively. / Wang Weizhong. / "November 2006." / Adviser: Jinling Tang. / Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5119. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 105-114) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.