Gap between evidence and physicians' knowledge and practice regarding hypertension and its drug treatment: a survey in a Chinese city.

BACKGROUND: Evidence-based medicine has come into its second decade. How prepared clinicians are in practicing it in particular in developing countries remains unclear. Thus we conducted this survey of physicians in urban hospitals in China to determine the size of the gap between research evidence and physicians' knowledge and practice regarding antihypertensive drugs for primary prevention of cardiovascular diseases in China. METHODS: A cross sectional survey by a face-to-face interview was conducted in 20 tertiary general hospitals in China in 2005. A total of 444 physicians (mostly cardiologists) in internal medicine who had treated at least one hypertensive patient in the past 12 months were invited for the interview on their perception of the cardiovascular risk of hypertension, the magnitude of the benefit of antihypertensive drugs, knowledge on the overall risk approach, first-line drugs used, the risk above which drug treatment is recommended, and knowledge on evidence-based medicine. RESULTS: A total of 444 of the 468 eligible physicians were successfully interviewed with a response rate of 94.9%. They estimated that a hypertensive man with an actual 5-year cardiovascular risk of 8.4% would have a 5-year cardiovascular risk of 40% (95%CI: 38% to 42%) if not treated, and have an absolute risk reduction and relative risk reduction from drug treatment by 20% (95%CI: 18% to 22%) and 39% (95%CI: 37% to 42%) respectively, as compared to 3.3% and 33% respectively shown in research evidence. On average, the physicians would recommend drug treatment at a number needed to treat (NNT) of 368 or smaller, as compared to the actual NNT of 50 for drug treatment in an average hypertensive Chinese. Fifty-five percent (95%CI: 50% to 59%) of them had never intently used the national hypertension guidelines. The majority still prescribed drugs primarily based on blood pressure alone by ignoring other risk factors or the overall risk and 78% (95 % CI: 76% to 83%) used new expensive drugs such as calcium channel blockers and angiotensin converting enzyme (ACE) inhibitors as first-line treatment. Only 13% (95%CI: 9% to 18%) could correctly interpret the NNT. Forty-three percent (95%CI: 39% to 48%) did not know the randomized controlled trial was scientifically the most rigorous among other study designs for evaluating the effectiveness of anti-hypertensive drugs. Ninety-two percent (95%CI: 90% to 94%) did not know they could start by searching systematic reviews when looking for evidence on the effectiveness of anti-hypertensive drugs as opposed to trials. Ninety-six percent (95%CI: 94% to 98%) did not know the Cochrane Library was an important source of systematic reviews. CONCLUSIONS: The surveyed physicians significantly over-estimated the cardiovascular risk of hypertension and the benefit of drug treatment, and had insufficient knowledge on the overall risk approach. They recommended drug treatment at a cardiovascular risk which was even much lower than the cutoff suggested for western populations, which would make many more people eligible for drug treatment. They also tended to prescribe new expensive drugs although the older cheaper ones may be more appropriate in many patients. They showed inappropriate knowledge on the basics of evidence-based medicine.

How willing are the public to pay for anti-hypertensive drugs for primary prevention of cardiovascular disease: a survey in a Chinese city.

BACKGROUND: Current recommendations on drug treatment of hypertension for primary prevention of cardiovascular disease are primarily determined by the evidence of effectiveness, disregard the resources available and values of people, and recommend a universally fixed risk cutoff for initiating drug treatment. The guidelines may have over-estimated the willingness of the public to accept and pay for these drugs and a fixed cutoff may not fit all populations. Moreover, the public may have been misinformed and are unable to make the right decision even if they are consulted. We conducted this study to address these issues and to describe the gap between current policy and what the public truly want. METHODS: A cross-sectional survey with face-to-face interviews of rural and urban residents in northern China. Before providing any information, we asked the residents whether they would accept drug treatment if they had hypertension and also asked them to estimate the 5-year cardiovascular risk in untreated hypertension and the benefits from anti-hypertensive drugs. We then informed the participants of necessary information and asked them above what benefit they would be willing to pay the current cost, and how much they would be willing to pay for the actual benefit, for anti-hypertensive drugs out of pocket. RESULTS: Eight hundred and eighty-seven rural residents and 921 urban residents were interviewed with a response rate of 97%. Ninety-five percent [95% confidence interval (CI) 94-96%] of the residents said they would take anti-hypertensive drugs if they had hypertension, although 91% (95% CI 89-92%) said they did not have sufficient knowledge to make a decision. Seventy-eight percent (95% CI 76-80%) believed that anti-hypertensive drugs were primarily to lower blood pressure or relieve symptoms. They over-estimated the cardiovascular risk of untreated hypertension by approximately 12 times and the absolute benefit of drug treatment by 20 times. Given the actual absolute benefit of the drugs, only 23% (95% CI 21-25%) were willing to pay the current annual cost of $500 Ren Min Bi (US$73.3, euro 54.8 as of 8 May 2009) for these drugs. Given the current cost, they were, on average, willing to pay for the drugs only when the 5-year cardiovascular disease risk was as high as 35% (95% CI 31-38%) or even higher. CONCLUSION: The public in China are significantly misinformed and considerably over estimate the risk of hypertension and the benefit of treatment. The public's willingness to pay for anti-hypertensive drugs is much lower than the current guidelines implicitly assume. The willingness to pay should be considered, along with other factors, when prescribing anti-hypertensive drugs to an individual patient or making hypertension guidelines for a population.

[Effect of daily or once weekly iron supplementation on growth and iron status of preschool children].

OBJECTIVE: The effect of daily and once weekly iron supplementation on hemoglobin(Hb), serum ferritin (SF), erythrocyte protoporphyrin (EFP) in whole blood, prevalence of iron deficiency, body weight and height of preschool children was compared in this study. METHODS: Preschool children (n = 353) from one kindergarten in Baotou City, was recruited. All children were divided into three groups by class, and received either daily or once weekly iron supplementation, or a placebo (control) for 14 weeks. RESULTS: The prevalence of iron deficiency was reduced in both intervention groups, and the rate in the group supplemented with iron once weekly was significantly lower than that of the control group(P < 0.05). The levels of Hb, SF, increased after once weekly and daily iron supplementation. Weight gain and WAZ were greater in children who received daily supplement than in those who received placebo. Height gain and HAZ were not significantly different among three groups. CONCLUSION: Daily micronutrient supplement can improve growth of preschool children. Once weekly iron supplement is effective same as daily supplement in improving iron status and reducing the prevalence of iron deficiency in the preschool children.