The article states that the hospitals' institutional review boards approved this pilot study. To the best of my knowledge, when you submit an application for IRB approval, you need to submit all clinical study documents, including a draft informed consent form. No clinical study may enrol any subject (including the use of any patient data) without obtaining the patient's signature on the informed consent form. Furthermore, the informed consent form states that all the procedures of the clinical study have been explained and are fully understood by the patient. So how did the investigator(s) receive IRB approval for a study without submitting the draft informed consent form? If they did submit the informed consent form, why did they not use it?