China's immense patient populations suffering from cancer, diabetes, cardiovascular illnesses, and a whole range of infectious diseases have captured the attention of drug and medical device companies across Europe and America. They are expanding research and testing facilities in China, not only because costs are low and it is relatively easy to recruit patients, but also because Beijing insists new drugs be tested locally before going on sale.

In the past, Chinese medical authorities have greenlighted risky experiments, including stem cell injections and treatments that involve altering the patient's genes. Moreover, people recruited into trials don't always understand what they have signed up for, but they rush to join because it may be their only chance to see a doctor.