Figure 1. Map of China with the 31 regions included in the present study. Taiwan, Hong Kong, and Macau were not included in the Second China National Sample Survey on Disability and thus were not included in our analyses. Cited from the National Administration of Surveying, Mapping, and Geoinformation website, 2007. Standard map service. http://www.sbsm.gov.cn/article/zxbs/dtfw/ accessed 31 August 2011.
