We correlated accrual and retention activities for six NIH funded longitudinal studies and three proprietary projects at CCH with financial data to determine the cost of recruitment and retention activities and of staff effort. We send birthday, holiday, and reminder cards and thank you notes. We fund 800 number voice mailboxes for patients if necessary. Participants are encouraged to enroll in weekly support groups. Staff generally makes two mail and three phone attempts to contact patients.
Staff attempts to contact all participants at least quarterly.
More research is needed to determine the most effective and efficient methodologies. National comparative studies are needed across population groups and over time.