Department of Health Education & Behavior, College of Health and Human Performance, University of Florida, Gainesville, Florida.
Division of Research, Kaiser Permanente Northern California, Oakland, California; Department of Internal Medicine, University of California, Davis, Sacramento, California.
Am J Prev Med. 2021 Oct;61(4):606-617. doi: 10.1016/j.amepre.2021.04.005.
Suboptimal and differential participant engagement in randomized trials-including retention at primary outcome assessments and attendance at intervention sessions-undermines rigor, internal validity, and trial conclusions.
First, this study describes Methods-Motivational Interviewing approach and strategies for implementation. This approach engages potential participants before randomization through interactive, prerequisite orientation sessions that illustrate the scientific rationale behind trial methods in accessible language and use motivational interviewing to diffuse ambivalence about participation. Then, this study examines the potential improvements in retention (proportion of participants assessed at follow-up visits) and attendance (e.g., mean percentage of intervention sessions attended, percentage of participants who attended 0 sessions) in 3 randomized weight-management trials that quickly added prerequisite orientations to their protocols following early signs of suboptimal or differential participant engagement (Supporting Health by Integrating Nutrition and Exercise [2009-2013, n=194]; Get Social [2016-2020, n=217]; GestationaL Weight Gain and Optimal Wellness [2014-2018, n=389]). Using a pre-post analytical design, adjusted estimates from regression models controlling for condition and assessment timepoint (analyses from 2020) are reported.
After adding prerequisite orientations, all 3 trials attained higher participant engagement. Retention at assessments was 11.4% and 17.3% higher (Get Social and Supporting Health by Integrating Nutrition and Exercise, respectively). Mean percentage of attendance at intervention sessions was 8.8% higher (GestationaL Weight Gain and Optimal Wellness), and 10.1% fewer participants attended 0 intervention sessions (Get Social). Descriptively, all the remaining retention and attendance outcomes were consistently higher but were nonsignificant. Across the trials, adding prerequisite orientations did not impact the proportion of eligible participants enrolled or the baseline demographics.
The Methods-Motivational Interviewing approach shows promise for increasing the rigor of randomized trials and is readily adaptable to in-person, webinar, and conference call formats.
All 3 trials are registered at www.clinicaltrials.gov (Supporting Health by Integrating Nutrition and Exercise: NCT00960414; Get Social: NCT02646618; and GestationaL Weight Gain and Optimal Wellness: NCT02130232).
随机试验中参与者参与度不理想且存在差异，包括在主要结局评估时的保留率和干预环节的出席率，这会影响研究的严谨性、内部有效性和试验结论。
首先，本研究介绍了方法——动机访谈方法及其实施策略。该方法通过互动式、预备性的介绍性课程，在随机分组前与潜在参与者接触，以通俗易懂的语言说明试验方法背后的科学原理，并运用动机访谈来消除对参与的矛盾心理。然后，本研究考察了在三个随机体重管理试验中增加预备性介绍对保留率（随访时评估的参与者比例）和出席率（例如，干预环节的平均出席百分比、出席 0 个环节的参与者百分比）的潜在改善情况，这些试验在出现参与者参与度不理想或存在差异的早期迹象后（支持健康，整合营养和锻炼[2009-2013，n=194]；社交支持[2016-2020，n=217]；妊娠期体重增加与最佳健康[2014-2018，n=389]）迅速在方案中增加了预备性介绍。采用前后分析设计，报告了控制条件和评估时间点（2020 年的分析）的回归模型调整后的估计值。
在增加预备性介绍后，所有三个试验的参与者参与度均有所提高。评估时的保留率分别提高了 11.4%和 17.3%（社交支持和支持健康，整合营养和锻炼）。干预环节的平均出席率提高了 8.8%（妊娠期体重增加与最佳健康），出席 0 个干预环节的参与者减少了 10.1%（社交支持）。描述性地，所有其他保留和出席结果均持续提高，但无统计学意义。在所有试验中，增加预备性介绍并不会影响合格参与者的入组比例或基线人口统计学特征。
方法——动机访谈方法有望提高随机试验的严谨性，并且易于适应现场、网络研讨会和电话会议等多种形式。
所有三个试验均在 www.clinicaltrials.gov 注册（支持健康，整合营养和锻炼：NCT00960414；社交支持：NCT02646618；以及妊娠期体重增加与最佳健康：NCT02130232）。
