In medical studies, treatments are tested within a group of study participants. You will be given a sentence of a study report in which your task is to list the phrases that give information about the participants of the study. You should list the phrases in the same order that they appear in the text, separated by commas. If no information about the participants is mentioned, just output "not found". Relevant information about participants include: gender, medical conditions, location, number of people participating. Do not contain participant mentions without relevant information.

[Q]: The 2 groups were comparable in terms of age , sex , symptoms and ipsilateral glomerular filtration rate .
[A]: not found


[Q]: Referral occurred at any stage of the patients ' EECU admission .
[A]: not found


[Q]: These 22 patients constituted the control group of a controlled trial and received standard outpatient clinic treatment during follow-up .
[A]:
22 patients