Recruitment of Men Into a Pragmatic Rural Primary Care Weight Loss Trial

Men remain underrepresented in behavioral weight loss trials and are more difficult to recruit compared to women. We describe recruitment response of men and women into a mixed-gender behavioral weight loss trial conducted within 36 rural primary care clinics. Participants were recruited through primary care clinics via direct mailings (n = 15,076) and in-clinic referrals by their primary care provider (PCP). Gender differences were examined in response rate to direct mailings, study referral source, and rates of proceeding to study screening, being eligible, and enrolling. Men had a lower response rate to direct mailings than women (7.8% vs. 17.7%, p < .001). Men (vs. women) responding to the mailing were more likely to respond by opt-in postcard (64.6% vs. 56.8%) and less likely to respond by phone (33.9% vs. 39.6%), p = .002. Among potential participants contacting the study (n = 2413), men were less likely to report being referred by PCPs (15.2% vs. 21.6%; p < .001), but were just as likely to proceed to screening, be eligible, and enroll. Men and women were more likely to proceed to screening when referred by PCPs (93.3% vs. 95.4%) compared to direct mailings (74.2% vs. 73.9%). Enrolled men were older (p < .001), more likely to be married (p = .04), and had higher levels of education (p = .01). Men were less likely than women to respond to direct mailings and to be referred by their PCP, but after contacting the study, had similar screening, eligibility, and enrollment rates. Encouraging and training providers to refer men during clinic visits may help recruit more men into primary care-based weight loss trials.