Maximizing the diversity of participants in a phase II clinical trial of optical technologies to detect cervical neoplasia

Abstract

Introduction: We compare the racial and ethnic demographics of our participants with the populations where our clinics are located (Texas and British Columbia) and investigate the reasons cited for participation.

Methods: We compared the distribution of participants by race/ethnicity to numbers from the 2000 United States Census and the 2001 Census of Canada. Each participant recorded her reasons for enrolling in the trial in her own words. This information was then categorized for analysis. For participants who provided more than one reason for participation, their responses were weighted accordingly to sum 100% for each race. All analyses were performed using SPSS v12.0 (SPSS, Chicago).

Results: In all, 1850 women participated in the study. Except for Asians in the Vancouver population and Native Americans in both populations, all minorities were recruited in proportions in excess of their respective proportions in the general population. Distinct differences in the reasons for participating between sites were noted. Houston patients were more likely to cite concern for one's own health as a reason for participating. On the other hand, Vancouver patients were more likely to cite helping others. This trend was found in both the screening and diagnostic populations.

Conclusions: We attribute our success in recruiting minorities to community outreach, our multicultural staff, and efforts to provide uniform care at all sites.

Figure 1

Comparison of the racial demographics of the State of Texas and the Houston study populations. Black women constitute 12% of the Texas population. Enrollment of black women into our trials were 18% for the screening trial and 17% for the diagnostic trial. Hispanic women were enrolled to the screening trial in equal proportion to their statewide numbers (32%) and slightly lower (20%) for the diagnostic trial. Asian women were over-enrolled in the screening trial (6%) and equally enrolled in the diagnostic study (3%) compared to the Texas demographics (3%). Native American women were enrolled equally in both studies (0.2%) compared to the state demographics (0.3%).

Figure 2

Comparison of the racial demographics of the Province of British Columbia and the Vancouver study populations. Women of Asian decent constitute 19% of the British Columbia population. Enrollment of Asian women into our trials were 12% for the screening trial and 7% for the diagnostic trial. Enrollment for both black and Hispanic women in the screening trial (1.3%) over-estimated their contribution to the British Columbia population (0.7% for black women and 0.6% for Hispanic women); however, the contributions to the diagnostic trial were similar (0.7%). Asian women represent constitute 11.5% of the Texas population. Native American women were under-represent in the screening (0.6%) and diagnostic (0.4%) trials when compared to the province demographics (4%).

Figure 3

Reasons for participation by race/ethnicity, Houston screening patients. The majority of participants in the Houston screening trial cited wanting to improve their health (46 - 66% among the minority groups) as the primary reason for participating in the trial. 10 – 19% presented wanting to help others as their reason for participating; and 14 – 25% cited interest in the study as their reason.

Figure 4

Reasons for participation by race/ethnicity, Vancouver screening patients. The majority of participants in the Vancouver screening trial cited wanting to help others (61 - 100% among the minority groups) as the primary reason for participating in the trial. 75% of the Hispanic women and all of the Native American women who participated listed a family history of cancer as a reason for participating. Personal health reasons were cited less frequently by the Vancouver participants than the Houston participants.

Figure 5

Reasons for participation by race/ethnicity, Houston diagnostic patients. The majority of participants in the Houston diagnostic trial cited wanting to “know more” (38 - 63% among the minority groups) as the primary reason for participating in the trial. 10 – 39% presented wanting to help others as their reason for participating. The highest proportion of participants that were recruited by family or friends into the study was among the Asian women (17%), which was much higher than the other groups.

Figure 6

Reasons for participation by race/ethnicity, Vancouver diagnostic patients. The majority of participants in the Vancouver diagnostic trial cited wanting to help others (61 - 100% among the minority groups) as the primary reason for participating in the trial.