Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
Clin Trials. 2012 Feb;9(1):80-9. doi: 10.1177/1740774511427929. Epub 2011 Nov 7.
Many factors have been identified that influence the recruitment of African Americans into clinical trials; however, the influence of eligibility criteria may not be widely appreciated. We used the experience from the Look AHEAD (Action for Health in Diabetes) trial screening process to examine the differential impact eligibility criteria had on the enrollment of African Americans compared to other volunteers.
Look AHEAD is a large randomized clinical trial to examine whether assignment to an intensive lifestyle intervention designed to produce and maintain weight loss reduces the long-term risk of major cardiovascular events in adults with type 2 diabetes. Differences in the screening, eligibility, and enrollment rates between African Americans and members of other racial/ethnic groups were examined to identify possible reasons.
Look AHEAD screened 28,735 individuals for enrollment, including 6226 (21.7%) who were self-identified African Americans. Of these volunteers, 12.9% of the African Americans compared to 19.3% of all other screenees ultimately enrolled (p < 0.001). African Americans no more often than others were lost to follow-up or refused to attend clinic visits to establish eligibility. Furthermore, the enrollment rates of individuals with histories of cardiovascular disease and diabetes therapy did not markedly differ between the ethnic groups. Higher prevalence of adverse levels of blood pressure, heart rate, HbA1c, and serum creatinine among African American screenees accounted for the greater proportions excluded (all p < 0.001).
Compared to non-African Americans, African American were more often ineligible for the Look AHEAD trial due to comorbid conditions. Monitoring trial eligibility criteria for differential impact, and modifying them when appropriate, may ensure greater enrollment yields.
许多因素已被确定会影响非裔美国人参与临床试验；然而，资格标准的影响可能尚未得到广泛认识。我们利用 Look AHEAD（糖尿病行动研究）试验筛选过程的经验，检查了资格标准对非裔美国人和其他志愿者入组的差异影响。
Look AHEAD 是一项大型随机临床试验，旨在检查将 2 型糖尿病患者分配到旨在减肥并维持体重的强化生活方式干预中，是否可以降低其长期发生主要心血管事件的风险。检查了非裔美国人和其他种族/族裔群体之间在筛选、资格和入组率方面的差异，以确定可能的原因。
Look AHEAD 对 28735 人进行了入组筛选，其中包括 6226 名（21.7%）自我认定为非裔美国人的志愿者。在这些志愿者中，12.9%的非裔美国人最终入组，而所有其他筛查者的入组率为 19.3%（p<0.001）。非裔美国人因失访或拒绝参加诊所就诊以确定资格而未入组的比例并不比其他人高。此外，有心血管疾病和糖尿病治疗史的个体的入组率在不同种族之间没有明显差异。非裔美国人筛查者中血压、心率、HbA1c 和血清肌酐不良水平的比例较高，这导致了更多的人被排除在外（均 p<0.001）。
与非裔美国人相比，由于合并症，非裔美国人更常不符合 Look AHEAD 试验的入组标准。监测试验入组标准的差异影响，并在适当情况下进行修改，可能会确保更大的入组率。
