Recruiting primary care physicians to qualitative research: Experiences and recommendations from a childhood cancer survivorship study.

PCP factors associated with higher opt in rates, and early responses, may be of interest to others considering engaging PCPs and/or their patients in cancer-related research, particularly qualitative or mixed-methods studies. Study resources may be best allocated to email follow-up, incentives, and personalization of study documents linking PCPs to patients. These efforts may improve PCP participation and the representativeness of study findings.