Chinese people spend a greater proportion of their lives in good health than people in other G20 countries

However, the incidence of stroke, ischaemic heart disease, road injury, diabetes, and some cancers all increased in incidence during the same period, and poor diet, tobacco use, and high blood pressure all now present substantial health risks in China which will need to be addressed.

The research, which shows how health in China has changed in the last two decades, and how it compares to other G20 countries, is published in The Lancet, and is part of the Institute of Health Metrics and Evaluation's (IHME) Global Burden of Disease 2010 study, a systematic, scientific collaboration by researchers worldwide to quantify the comparative magnitude of health loss to diseases, injuries, and risk factors by age, sex, and geography over time. The new study's lead authors are Professor Gonghuan Yang, of the Peking Union Medical College, and Dr Yu Wang, of the Chinese Center for Disease Control and Prevention, both in Beijing, China.

In 2010, China experienced the lowest number of years of life lost to disability (YLDs) across the G20, indicating that people in China live a greater proportion of their life in good health than do people in other G20 countries. However, life expectancy in China in 2010 was slightly under 76 years, about average for G20 countries, and considerably lower than neighbouring Japan, which has the world's highest life expectancy, at over 82 years.

"The speed of decline in numbers of premature deaths resulting from infectious diseases and neonatal causes in China over the last two decades could provide a model for other developing countries," says Professor Yang, "But there are still challenges to be met, including rising rates of HIV infection, and tackling disease burden and child malnutrition in some poor provinces, where the burden of communicable diseases is still high."

The researchers' analysis of premature mortality and disability together provides an overall picture of the leading health problems in China, with the main causes of death and disability in the country identified as cardiovascular disorders (stroke and ischaemic heart disease), cancers (lung and liver), low back pain and depression, chronic obstructive pulmonary disease, diabetes, road injuries, and falls. In 1990, heart disease was the seventh most important cause of premature mortality; in 2010 it had risen to second place, just behind stroke, the number one cause of premature mortality. Road injury was the tenth most important cause of premature mortality in 1990, but in 2010 it had risen to fourth place.

The leading risk factor for disability and death was found to be poor diet, especially diets low in fruits or whole grains, and high in sodium (salt), with the second most important risk factor high blood pressure, and tobacco the third. Dietary risks and high blood pressure worsened in China compared with the G20 average between 1990 and 2010.

According to Dr Wang, "The burden of diseases attributable to individual behaviours and practices is steadily rising in China. The most important behaviours resulting in increased illness and deaths included diets low in fruit, high in sodium, and low in whole grains, smoking, alcohol, and physical inactivity, and the Chinese government needs to take responsibility for expansion of prevention strategies for behavioural risks. Even small reductions in these risks could generate substantial benefits."

Addressing these new and substantial risks to Chinese health will require multisectoral action at national, provincial, and local levels, say the authors, and these actions will need careful documentation of the health harms that exist at a local level, and the potential for affordable alternative policies to reduce these harms. Moreover, increased investment will be needed to recruit further workers to the disciplines needed to address China's emerging health issues, including psychiatry, rheumatology, rehabilitation medicine, audiology, and ophthalmology.

"Health loss and health-care costs from mental disorders, musculoskeletal disorders, neurological disorders, and vision and hearing loss will continue to rise," said Dr Christopher Murray, IHME Director and one of the authors of the study. "Policies to help prevent and manage these disorders cost-effectively will be critical."