Effect of a knowledge-based and skills-based programme for physicians on risk of sexually transmitted reinfections among high-risk patients in China: a cluster randomised trial oleh Don Operario, PhD, Prof. Debin Wang, MD, Nickolas D Zaller, PhD, Mei-Fen Yang, MPH, Kathleen Blaney, MPH, Jing Cheng, MPH, Qian Hong, PhD, Prof. Hongbo Zhang, PhD, Jing Chai, MD, Gregory Szekeres, Jerome Galea, PhD, Dr Prof. Thomas J Coates, PhD