A majority of China's private nursing houses are understaffed, an official survey showed.

The survey, conducted by the China National Working Commission on Ageing, began in August 2008 and covered all mainland regions.

It revealed cash-strapped private nursing homes are reducing staff numbers to lower costs. The survey also showed such nursing homes may be insufficiently supervised.

"Staff at nursing homes are doing hard work for long hours, so many of them are choosing to leave the sector," it said.

Only a small proportion of the sector's staff have professional qualifications, so service quality is not assured, the survey said, suggesting a need to strengthen personnel training in the sector.

At the end of 2009, there were about 167 million Chinese aged above 60, making up 12.5 percent of the total population, statistics show.

Vice Premier Hui Liangyu, also director of the China National Working Commission on Ageing, said last month the home-based services for the aged should be combined with community and nursing home services to improve old people's living environment.

The survey found price, service quality and distance from home are the major factors affecting people's choice of nursing home.

The report said by August 2008, China had more than 4,100 private nursing houses, accounting for 10.6 percent of the country's nursing homes. The homes housed more than 230,000 old people.

There were more nursing houses in eastern China than in the central and western parts. Northeastern Heilongjiang Province boasted more than 600 nursing houses, topping the nation, while northwestern Qinghai Province and southwestern Tibet Autonomous Region had no private nursing homes at all, the survey said.