Retention of black and white participants in the selenium and vitamin E cancer prevention trial (SWOG-coordinated intergroup study S0000).

BACKGROUND: Disproportionally low retention of minority populations can adversely affect the generalizability of clinical research trials. We determine the overall retention rates for White and Black participants from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and explore participant and site characteristics associated with retention failure (study disengagement) for these groups. METHODS: A secondary analysis of 28,118 White (age ≥55), and 4,322 Black (age ≥ 50) SELECT participants used multivariate Cox regression to estimate overall retention rates and to calculate HRs and 95% confidence intervals (CI). RESULTS: Blacks had higher age-adjusted risk of disengagement than Whites (HR, 1.92; 95% CI, 1.77-2.08). Among Black participants, those ages 50 to 54 were at three times the risk of disengagement than those ≥65 years of age (HR, 3.61; 95% CI, 2.41-5.41). Blacks age ≥65 had 1.6 times the risk of disengagement than Whites age ≥65 (HR, 1.60; 95% CI, 1.38-1.87). By 6 years after randomization, 84% of Whites and 69% of Blacks remained engaged in the study. Current smoking status was an independent risk factor for study disengagement for both White and Black participants. For both groups, sites whose staffs missed SELECT training sessions or who received SELECT Retention and Adherence grants were associated with increased and decreased disengagement risks, respectively. CONCLUSIONS: SELECT retention was disproportionately lower for Blacks than for Whites. IMPACT: The observed difference in retention rates for Blacks and Whites and factors identified by race for study disengagement in SELECT may inform retention efforts for future long-term, cancer prevention trials.

Impact of supplemental site grants to increase African American accrual for the Selenium and Vitamin E Cancer Prevention Trial.

BACKGROUND: African American accrual to prevention trials at rates representative of the disease burden experienced by this population requires additional resources and focused efforts. PURPOSE: To describe the rationale, context, and criteria for selection of sites that received Minority Recruitment Enhancement Grants (MREGs) to increase African American recruitment to the Selenium and Vitamin E Cancer Prevention Trial (SELECT). To determine if African American accrual was higher among the 15 MREG sites when compared with similar nonawarded sites. METHODS: Changes in African American accrual at sites that received MREGs are compared with changes in a group of 15, frequency-matched, nonawarded sites using a quasi-experimental, post hoc analysis. Successful and unsuccessful recruitment strategies reported by the MREG sites are described. RESULTS: The increased number of African American participants accrued per month at MREG sites post-funding was higher than the change at comparison sites by a factor of 3.38 (p = 0.004, 95% CI: 1.51-7.57). An estimated 602 additional African American participants were recruited at MREG sites due to MREG funding, contributing to the overall 14.9% African American recruitment. Successful recruitment strategies most reported by MREG sites included increasing staff, transportation resources, recruiting through the media, mailings, and prostate cancer screening clinics during off-hours. LIMITATIONS: Comparison sites were chosen retrospectively, not by randomization. Although comparison sites were selected to be similar to MREG sites with regard to potential confounding factors, it is possible that unknown factors could have biased results. Cost-effective analyses were not conducted. CONCLUSIONS: MREG sites increased African American accrual in the post-funding period more than comparison sites, indicating MREG funding enhanced the sites' abilities to accrue African American participants. Targeted grants early in the accrual period may be a useful multi-site intervention to increase African American accrual for a prevention study where adequate African American representation is essential.

Minority recruitment to the Selenium and Vitamin E Cancer Prevention Trial (SELECT).

BACKGROUND: Previous large chemoprevention studies have not recruited significant numbers of minorities. The Selenium and Vitamin E Cancer Prevention Trial (SELECT) is a large phase III study evaluating the impact of selenium and vitamin E on the clinical incidence of prostate cancer. Over 400 SELECT study sites in the USA, Canada, and Puerto Rico recruited men to this trial. The SELECT recruitment goal was 24% minorities, with 20% black, 3% Hispanic, and 1% Asian participants. The goal for black participants was set at 20% because of their proportion in the United States population and their prevalence of prostate cancer. METHODS: The minority recruitment strategies in SELECT were to: 1) consider minority recruitment during site selection; 2) expand the eligibility criteria by lowering the age criterion for black men and including men with controlled co-morbid illnesses; 3) develop a national infrastructure; 4) give additional funds to sites with the potential to increase black enrollment; and 5) provide resources to maximize free media opportunities to promote SELECT. RESULTS: SELECT recruitment began in August 2001 and was intended to last five years, but concluded two years ahead of schedule in June 2004. Of the 35 534 participants enrolled, 21% were minorities, with 15% black, 5% Hispanic, and 1% Asian. CONCLUSIONS: Careful planning, recruitment of large numbers of clinical centers and adequate resources accomplished by the combined efforts of the National Cancer Institute (NCI), Southwest Oncology Group (SWOG), SELECT Recruitment and Adherence Committee (RAC), SELECT Minority and Medically Underserved Subcommittee (MMUS), and the local SELECT sites resulted in attainment of the estimated sample size ahead of schedule and recruitment of the largest percentage of black participants ever randomized to a cancer prevention trial.