Tracking and tracing of participants in two large cancer screening trials.

BACKGROUND: Many clinical trials rely on participant report to first learn about study events. It is therefore important to have current contact information and the ability to locate participants should information become outdated. The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) and the Lung Screening Study (LSS) component of the National Lung Screening Trial, two large randomized cancer screening trials, enrolled almost 190,000 participants on whom annual contact was necessary. Ten screening centers participated in both trials. Centers developed methods to track participants and trace them when necessary. We describe the methods used to keep track of participants and trace them when lost, and the extent to which each method was used. METHODS: Screening center coordinators were asked, using a self-administered paper questionnaire, to rate the extent to which specific tracking and tracing methods were used. RESULTS: Many methods were used by the screening centers, including telephone calls, mail, and internet searches. The most extensively used methods involved telephoning the participant on his or her home or cell phone, or telephoning a person identified by the participant as someone who would know about the participant's whereabouts. Internet searches were used extensively as well; these included searches on names, reverse-lookup searches (on addresses or telephone numbers) and searches of the Social Security Death Index. Over time, the percentage of participants requiring tracing decreased. CONCLUSIONS: Telephone communication and internet services were useful in keeping track of PLCO and LSS participants and tracing them when contact information was no longer valid.

Recruitment methods employed in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

BACKGROUND: The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) is a US National Cancer Institute (NCI)-funded randomized controlled trial designed to evaluate whether certain screening tests reduce mortality from prostate, lung, colorectal, and ovarian cancer. To obtain adequate statistical power, it was necessary to enroll over 150,000 healthy volunteers. Recruitment began in 1993 and ended in 2001. PURPOSE: Our goal is to evaluate the success of recruitment methods employed by the 10 PLCO screening centers. We also provide estimates of recruitment yield and cost for our most successful strategy, direct mail. METHODS: Each screening center selected its own methods of recruitment. Methods changed throughout the recruitment period as needed. For this manuscript, representatives from each screening center provided information on methods utilized and their success. RESULTS: In the United States between 1993 and 2001, ten screening centers enrolled 154,934 study participants. Based on participant self-report, an estimated 95% of individuals were recruited by direct mail. Overall, enrollment yield for direct mail was 1.0%. Individual center enrollment yield ranged from 0.7% to 3.8%. Cost per enrolled participant was $9.64-35.38 for direct mail, excluding personnel costs. LIMITATIONS: Numeric data on recruitment processes were not kept consistently at individual screening centers. Numeric data in this manuscript are based on the experiences of 5 of the 10 centers. CONCLUSIONS: Direct mail, using rosters of names and addresses from profit and not-for-profit (including government) organizations, was the most successful and most often used recruitment method. Other recruitment strategies, such as community outreach and use of mass media, can be an important adjunct to direct mail in recruiting minority populations.