Recruitment
pain
CHRONIC PAIN
Participants were recruited from the online database ResearchMatch, a national health volunteer registry that was created by several academic institutions and supported by the United States National Institutes of Health (NIH) as part of the Clinical Translational Science Award (CTSA) program [Patients who fulfilled the following criteria were considered eligible for the study: any gender, location in the United States, age above 21, chronic pain problem (> 3 months) with current pain. Eligibility was confirmed using ResearchMatch demographics filters together with an eligibility screener verifying eligibility.