This study was conducted in three tertiary hospitals in Xiamen City, a large urban city in Southern China. Xiamen City has a population of more than 3.5 million, of which 82.6% aged 15–64 years and 4.6% aged 65 years or older.
The gross domestic product (GDP) of Xiamen City has been steadily increasing in the past few years and the City’s GDP of the first half of 2013 was US$ 21.06 billion