Richard Smith on health research in rural China

Richard SmithThe differences between rural and urban China are stark. Beijing, Shanghai, and other major cities are filled with new buildings, best illustrated by those built for the Olympics, whereas rural China has as many as 300 million people living on under a dollar a day, more than any other country. Indeed, China can be described as three countries: a low income country in the West, a middle income country in the middle, and a developed country in the East.

People living in the big cities have access to the latest medical technology, whereas those living in the countryside are served by a “village doctor” (many of them once the famous barefoot doctors) with limited training. So far most health research has been conducted in large hospitals in the cities, but a new programme—the China Rural Health Initiative—plans to build a platform for research in rural areas  Last week in Beijing I heard the plans for the initiative.

The China Rural Health Initiative is the flagship programme of the China International Center for Chronic Disease Prevention, which is based at the George Institute China, with Peking University Health Science Center its lead domestic partner. There are also five partners from five of the provinces closest to Beijing, which together have about 190 million inhabitants, and six international partners, including the George Institute in Sydney, Duke University, and Imperial College.

One of the first studies to be conducted will be a cluster randomised trial of training the village doctors and providing community health education to prevent heart disease and stroke. People in Northern China use huge amounts of salt and consequently have high levels of hypertension and stroke. Many people have a daily consumption of 12 g or even more (when WHO recommends no more than 5 g and many think it should be 2.5 g), and poorer people use more salt.

The village doctors will receive training in a simple, low cost, evidence based package for high risk patients that includes regular blood pressure tests, free medication, and salt reduction and potentially substitution. The doctors will also be given a health education kit and incentivised to practise prevention. The primary outcome measure of the trial will be the proportion of high risk people treated with at least one drug, and secondary outcomes will be blood pressure and the control rate of hypertension.

There is also a provisional plan to at the same time conduct a trial of community based education on reducing salt consumption. Twenty five townships with between 18 000 and 26 000 inhabitants would receive both interventions (training of village doctors and community education), 25 neither, and 25 each one or the other. The hope is that this will lead to a package that could introduced across rural China.

A third possible study if funding can be found will be a randomised trial of salt substitution with high risk individuals. Families with high risk individuals would be randomised to receive free salt substitute (containing 65% salt, 25% potassium chloride, which lowers blood pressure, and 10% magnesium sulphate) or to the control group. A pilot study has already shown that salt substitution can lower blood pressure by 5 mg Hg (about the same as one drug), but the proposed trial would look for a reduction in stroke, heart attack, and death. Because of the known reduction in blood pressure there is every reason to expect a reduction in events and deaths, but the investigators judge that such a trial would lead to a change in policy in China and beyond.

It’s possible to do a trial like this in rural China because most salt is added by people when cooking, whereas people in Chinese cities and the developed world receive most of their salt through processed foods.

A fourth possible study, again dependent on funding, would try to validate a method of verbal autopsy. Physical autopsy is not possible in most developing countries, and the data for the global burden of disease are based on doubtful evidence. The study would compare the diagnosis reached in those who die in hospital (the best “gold standard” available) with a verbal autopsy, a series of questions, used with carers one to three months after death. This would be done for the top 20 to 40 causes of death, and if the verbal autopsy proves reliable then a later study would quantify the cause of death across communities.

The great attraction of establishing a reliable platform for research is that other studies can be conducted without the difficulties and cost of developing a platform, and already there is interest in studying biomarkers, interventions to prevent progression of chronic kidney disease (which is known to be common in rural China), and telemonitoring to speed treatment of patients with heart attacks. Remarkably, another possible study is a randomised trial of conservative versus surgical treatment of hip fracture; this might be possible in rural China because it seems that many patients are treated conservatively.

No doubt many other studies will be proposed, and the hope must be that the result is not simply lots of publications but real improvements for the vulnerable, poor people in rural China.

Competing interest: Richard Smith is director of the UnitedHealth Chronic Disease Initiative, which together with the National Heart, Lung and Blood Institute is funding the China International Center for Chronic Disease Prevention.