Challenges faced in recruiting patients from primary care practices into a physical activity intervention trial

Background. Special challenges are encountered when clinical trial recruitment targets a physician practice-based population, as opposed to recruiting from the community. Since most published information about recruitment has focused on the latter group, summation of successful primary- care-based recruitment strategies could prove useful for future trials recruiting from this population. Methods. The Activity Counseling Trial (ACT) is a multicenter, randomized clinical trial that evaluated approaches to primary care-based interventions to increase physical activity in sedentary adults 35-75 years of age. Fifty-four clinicians from eight practices recruited 874 participants from three U.S. sites. Recruitment challenges that related, in great part, to the primary care setting included: (1) focusing on patients from ACT physician practices who had regularly scheduled or intend- to-schedule appointments within the next year; (2) placing trial staff in the clinical offices for recruitment purposes; and (3) placing trial interventionists in the physicians' offices. Other challenges were related to recruitment of minorities and men. Results. Patient mailing yielded 43.4% of all randomized participants, followed by office-based questionnaires (32.5%) and direct telephone contact (21.6%). Based on a retrospective cost-effective analysis (indirect costs excluded), the self-administered office-based questionnaire was the least costly strategy for one site ($14/randomized participant), followed by patient mailing at another site ($58). The direct telephone contact method utilized at one site serving primarily a minority population yielded a per randomized participant cost of $80. Conclusions. Recruitment of clinical trial participants from practice-based populations requires modification of the strategies used to recruit from the community. Multiple strategies should be employed, followed closely for their respective yields, and adapted as needed.