Standiford Debra A, Morwessel Nancy, Bishop Franziska K, Thomas Joan M, Smith Emily, Crandell Jamie, Driscoll Kimberly A, Hunter Christine M, Kichler Jessica C, Maahs David M, Mayer-Davis Elizabeth J, Seid Michael
Cincinnati Children's Hospital Medical Center, University of Cincinnati Medical School, Cincinnati, OH, United States.
Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, CO, United States.
Contemp Clin Trials Commun. 2018 Sep 21;12:68-75. doi: 10.1016/j.conctc.2018.09.005. eCollection 2018 Dec.
The Flexible Lifestyle Empowering Change Study (FLEX) is a multi-site randomized controlled trial to test the efficacy of an adaptive behavioral intervention to promote self-management and improve glycemic control for adolescents with type 1 diabetes mellitus. A two-step recruitment process was used to optimize study retention by facilitating informed decision-making regarding participation.
Those who expressed interest at first contact were given more detailed study information followed by telephone calls to the adolescents and their parents to answer questions and explore potential barriers to participation before making a decision regarding study enrollment.
Of 694 eligible adolescents who were invited to participate, 397 (57.2%) expressed interest when initially contacted (Step 1). Upon completion of the follow-up telephone calls (Step 2), 276 (39.8%) still agreed to participate; and 258 (37.2%) enrolled and completed a baseline visit with a parent/guardian. Completion rates for measurement visits remained high throughout the study, with an end-of-study retention rate of 93.4%; and only 12 (4.7%) families withdrew from the study.
The two-step recruitment process encourages potential participants to thoughtfully evaluate their willingness to participate, as well as their ability to make a commitment to the full completion of study requirements. When demonstrating the efficacy of a randomized controlled trial, it may be preferable to accept lower recruitment rates in order to optimize retention rates. The additional time and effort required to implement this two-step process is worthwhile. With a high retention rate, we can be more confident that the outcomes of the randomized controlled trial actually reflect the impact of the intervention.
灵活生活方式促进改变研究（FLEX）是一项多中心随机对照试验，旨在测试一种适应性行为干预措施对1型糖尿病青少年自我管理和改善血糖控制的疗效。采用两步招募流程，通过促进关于参与的知情决策来优化研究保留率。
首次联系时表示感兴趣的人会收到更详细的研究信息，随后会给青少年及其父母打电话，在决定是否参加研究之前回答问题并探讨潜在的参与障碍。
在694名被邀请参与的符合条件的青少年中，397名（57.2%）在最初联系时（第1步）表示感兴趣。在完成后续电话沟通（第2步）后，276名（39.8%）仍同意参与；258名（37.2%）登记并与父母/监护人完成了基线访视。在整个研究过程中，测量访视的完成率一直很高，研究结束时的保留率为93.4%；只有12个（4.7%）家庭退出了研究。
两步招募流程鼓励潜在参与者认真评估他们参与的意愿以及承诺完全完成研究要求的能力。在证明随机对照试验的疗效时，为了优化保留率，接受较低的招募率可能更可取。实施这个两步流程所需的额外时间和精力是值得的。由于保留率高，我们可以更有信心随机对照试验的结果实际上反映了干预的影响。
