Recruitment strategies and challenges in a large intervention trial: Systolic Blood Pressure Intervention Trial.

BACKGROUND: The Systolic Blood Pressure Intervention Trial is a multicenter, randomized clinical trial of 9361 participants with hypertension who are ≥50 years old. The trial is designed to evaluate the effect of intensive systolic blood pressure control (systolic blood pressure goal <120 mm Hg) compared to standard control (systolic blood pressure goal <140 mm Hg) on cardiovascular events using commonly prescribed antihypertensive medications and lifestyle modification. OBJECTIVE: To describe the recruitment strategies and lessons learned during recruitment of the Systolic Blood Pressure Intervention Trial cohort and five targeted participant subgroups: pre-existing cardiovascular disease, pre-existing chronic kidney disease, age ≥75 years, women, and minorities. METHODS: In collaboration with the National Institutes of Health Project Office and Systolic Blood Pressure Intervention Trial Coordinating Center, five Clinical Center Networks oversaw clinical site selection, recruitment, and trial activities. Recruitment began on 8 November 2010 and ended on 15 March 2013 (about 28 months). Various recruitment strategies were used, including mass mailing, brochures, referrals from healthcare providers or friends, posters, newspaper ads, radio ads, and electronic medical record searches. RESULTS: Recruitment was scheduled to last 24 months to enroll a target of 9250 participants; in just over 28 months, the trial enrolled 9361 participants. The trial screened 14,692 volunteers, with 33% of initial screens originating from the use of mass mailing lists. Screening results show that participants also responded to recruitment efforts through referral by Systolic Blood Pressure Intervention Trial staff, healthcare providers, or friends (45%); brochures or posters placed in clinic waiting areas (15%); and television, radio, newspaper, Internet ads, or toll-free numbers (8%). The overall recruitment yield (number randomized/number screened) was 64% (9361 randomized/14,692 screened), 77% for those with cardiovascular disease, 79% for those with chronic kidney disease, 70% for those aged ≥75 years, 55% for women, and 61% for minorities. As recruitment was observed to lag behind expectations, additional clinics were included and inclusion criteria were broadened, keeping event rates and trial power in mind. As overall recruitment improved, a greater focus on subgroup recruitment was implemented. CONCLUSION: Systolic Blood Pressure Intervention Trial met its overall projected recruitment goal using diverse, locally adapted enrollment strategies to specifically target persons with cardiovascular disease, chronic kidney disease, ≥75 years old, women, and minority subgroups. The trial exceeded its recruitment goal for minorities but found it a challenge to meet the competing demands of the targeted goals for recruiting into the remaining four subgroups. Important lessons include the imperative to monitor the recruitment process carefully, decide early to add new clinics or modify inclusion and exclusion criteria if recruitment lags, and consider limiting enrollment to subgroups only. We found benefit in using multiple recruitment sources simultaneously; mass mailing produced the largest number of participants, but referrals resulted in the greater randomization yield.

Participants' Views of Retention Materials Used in the PLCO Cancer Screening Trial.

OBJECTIVE: To obtain information from participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial regarding their perception of the retention materials employed by the screening centers. Also, to determine the viability of using email or the internet as a data collection tool with an older population. DESIGN: Three of ten PLCO screening centers queried participants towards the end of the study (2010) as to their opinions of the various retention materials and whether they would have been willing to use electronic communication for study activities, had the option been available. SETTING: The questionnaires were administered by mail, and responses were returned to the originating screening center. PARTICIPANTS: The participants in this study consisted of all the active participants at three PLCO screening centers: the University of Colorado Anschutz Medical Campus, the University of Utah, and Henry Ford Health System. METHODS: A short, self-administered questionnaire was mailed to all active participants at three PLCO centers (n=41,482). This was a one-time mailing with no follow-up, as the responses were designed to be anonymous in order to obtain the most honest responses. RESULTS: The response rate was 62%. Of respondents, 97% reported their PLCO experience was good or excellent. Nearly 50% of respondents indicated that receipt of an annual newsletter made them more likely to participate; newsletter features they reported as most important were those that conveyed information on cancer, study findings, and how their data were being used. Results did not support study coordinators' suppositions that receipt of a token gift or birthday card by participants was important for retention. Fewer than 30% of respondents indicated that they would have been unwilling to use a secure website to complete study forms. CONCLUSION: These data indicate the importance of querying participants rather than relying on impressions of study staff, and also indicate that the internet will be a viable means of data collection in future prevention studies that include older Americans.

Building Successful Relationships in the PLCO Cancer Screening Trial.

Biomedical research cannot succeed without funding, knowledgeable staff, and appropriate infrastructure. There are however equally important but intangible factors that are rarely considered in planning large multidisciplinary endeavors or evaluating their success. The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial required extensive collaborations between individuals from many fields, including clinicians, clinical trialists, and administrators; it also addressed questions across the spectrum of cancer prevention and control. In this manuscript, we examine the experiences and opinions of trial staff regarding the building of successful relationships in PLCO. We summarize, in narrative form, data collected using open-ended questionnaires that were administered to the National Cancer Institute project officers, coordinating center staff, screening center principal investigators, and screening center coordinators in 2015, about 3 years after publication of the final primary trial manuscript. Trust, respect, listening to others, and in-person interaction were frequently mentioned as crucial to building successful relationships.

Non-compliance with the initial screening exam visit in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

OBJECTIVE: Identify predictors of non-compliance with first round screening exams in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. METHOD: The PLCO was conducted from 1993 to 2011 at 10 US institutions. A total of 154,897 healthy men and women ages 55-74 years were randomized. Intervention arm participants were invited to receive gender-appropriate screening exams for prostate, lung, colorectal and ovarian cancer. Using intervention-arm data (73,036 participants), non-compliance percentages for 13 covariates were calculated, as were unadjusted and adjusted odds ratios (ORs), and 95% confidence intervals. Covariates included demographic factors as well as factors specific to PLCO (e.g., method of consent, distance from screening center). RESULTS: The rate of non-compliance was 11% overall but varied by screening center. Significant associations were observed for most covariates but indicated modest increases or decreases in odds. An exception was the use of a two-step consent process (consented intervention arm participants for exams after randomization) relative to a one-step process (consented all participants prior to randomization) (OR: 2.2, 95% CI: 2.0-2.5). Non-compliance percentages increased with further distance from screening centers, but ORs were not significantly different from 1. CONCLUSIONS: Many factors modestly influenced compliance. Consent process was the strongest predictor of compliance.

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.