The study was carried out as a randomized parallel controlled
trial. It was conducted in collaboration with the
Nanjing Community Health Service Center. Nanjing is
located in southeastern China and is the provincial capital
of Jiangsu province—one of the most developed provinces
in China.
The participants were recruited from the community
governed by this Community Health Service Center in
2009. The study had obtained the approval of the Medical
Ethics Committee of Southeast University.