Cook Wendy A, Doorenbos Ardith Z
Naval Medical Center San Diego, 34800 Bob Wilson Drive, San Diego, CA 92134.
Biobehavioral Nursing and Health Systems, Box 357266, University of Washington, Seattle, WA 98195.
Mil Med. 2017 Mar;182(3):e1580-e1587. doi: 10.7205/MILMED-D-16-00225.
The success of military-relevant health research often depends on recruiting adequate numbers of U.S. military service members as research participants. Researchers have reported difficulties in recruiting service member research participants. Reviews of ClinicalTrials.gov, an online clinical trial registry of publicly and privately sponsored studies, have identified challenges in participant recruitment and barriers to study completion in various research populations. The purpose of this study was to identify indications of difficulty recruiting U.S. military service members as research participants based on data from study records in ClinicalTrials.gov.
Records of studies starting between 2005 and 2014 were collected from ClinicalTrials.gov and updated through January 2016. Three hundred and two studies that included ≥25% U.S. military service member research participants were (1) compared to a comparison group of 302 studies, each with <5% service member participants and (2) compared by the proportion of service member participants within studies in the military group ("many" ≥25% but <100% service members and "all" 100% service members). Groups were evaluated and compared for recruitment status; reasons for study withdrawal, termination, or suspension; achievement of ≥85% of the anticipated enrollment; and differences in achieving recruitment goals according to study sponsor.
Twelve percent of studies in the military group had been withdrawn, terminated, or suspended; enrollment and funding problems were the most common reasons. The comparison group had 11% of studies withdrawn, terminated, or suspended; the most common reasons were enrollment problems and sponsor decision. All study groups had indications of difficulty adequately achieving participant enrollment goals. Among studies with known anticipated and actual enrollment, approximately half in both the military group (47.9%) and comparison group (50.3%) achieved ≥85% of the anticipated enrollment (p = 0.722). Half of studies with many service members and 44% of studies with all service members achieved ≥85% of the anticipated enrollment (p = 0.600). In comparing the many and all service member subgroups, significant differences were found in the median values for anticipated enrollment and actual enrollment, even when accounting for Bonferroni correction. Evaluations of mean values did not show a statistical difference between the military subgroups. There were no significant differences according to study sponsor (military, academic, Veterans Affairs, National Institutes of Health, nonprofit organization, or industry) for a study achieving or not achieving ≥85% of the anticipated enrollment.
This review supports anecdotal reports of difficulty recruiting service members as research participants. However, the findings also indicate that in many regards, there is not much difference in the difficulties recruiting service members versus other research participants. Findings suggest that it is often difficult to recruit research participants regardless of the specific population or type of study sponsor, and that studies with either many or all service member participants have similar achievement of recruitment goals. Findings in this study may be useful for those who design research that includes service members or for those who are apprehensive about including service members in their research.
与军事相关的健康研究的成功往往取决于招募足够数量的美国军人作为研究参与者。研究人员报告了在招募军人研究参与者方面存在困难。对ClinicalTrials.gov（一个由公共和私人资助研究的在线临床试验注册库）的回顾发现，在不同研究人群中，参与者招募存在挑战，研究完成存在障碍。本研究的目的是根据ClinicalTrials.gov中研究记录的数据，确定招募美国军人作为研究参与者存在困难的迹象。
收集了2005年至2014年开始的研究记录，并更新至2016年1月。将302项纳入≥25%美国军人研究参与者的研究（1）与302项每项参与者中军人比例<5%的对照组进行比较，（2）按军事组内研究中军人参与者的比例（“多数”≥25%但<100%军人和“全部”100%军人）进行比较。对各小组的招募状况进行评估和比较；研究撤回、终止或暂停的原因；达到预期招募人数≥85%的情况；以及根据研究资助者在实现招募目标方面的差异。
军事组中有12%的研究被撤回、终止或暂停；入组和资金问题是最常见的原因。对照组中有11%的研究被撤回、终止或暂停；最常见的原因是入组问题和资助者决定。所有研究组都有难以充分实现参与者招募目标的迹象。在已知预期和实际招募人数的研究中，军事组（47.9%）和对照组（50.3%）中约一半达到了预期招募人数的≥85%（p = 0.722）。有多数军人参与的研究中有一半，全部为军人参与的研究中有44%达到了预期招募人数的≥85%（p = 0.600）。在比较多数和全部军人参与者亚组时，即使考虑了Bonferroni校正，预期招募人数和实际招募人数的中位数仍存在显著差异。对平均值的评估未显示军事亚组之间存在统计学差异。根据研究资助者（军事、学术、退伍军人事务部、国立卫生研究院、非营利组织或行业），对于达到或未达到预期招募人数≥85%的研究，没有显著差异。
本综述支持了关于招募军人作为研究参与者存在困难的传闻报道。然而，研究结果还表明，在许多方面，招募军人与招募其他研究参与者的困难程度没有太大差异。研究结果表明，无论特定人群或研究资助者类型如何，招募研究参与者通常都很困难，并且有多数或全部军人参与者的研究在实现招募目标方面相似。本研究的结果可能对设计包含军人的研究的人员或对在其研究中纳入军人感到担忧的人员有用。
