instruction:
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.
question:
In adjusted analyses , parents who reported that their child had ASD did not have significantly higher out-of-pocket costs or spend more time on caregiving activities compared with control parents .
answer:
parents who reported that their child had ASD


question:
However , among OC users , nonsmokers had significantly greater heart rate and diastolic blood pressure reactivity to stress .
answer:
OC users


question:
There were no significant differences in serum levels of cholesterol , total protein , lactate dehydrogenase , aspartate aminotransferase , alanine aminotransferase , Na⁺ , Cl⁻ , K⁺ , and Ca²⁺ .
answer:

not found