Dodge Hiroko H, Katsumata Yuriko, Zhu Jian, Mattek Nora, Bowman Molly, Gregor Mattie, Wild Katherine, Kaye Jeffrey A
Layton Aging and Alzheimer's Disease Center, Department of Neurology, Oregon Health & Science University, Portland, OR, USA.
Trials. 2014 Dec 23;15:508. doi: 10.1186/1745-6215-15-508.
Trials aimed at preventing cognitive decline through cognitive stimulation among those with normal cognition or mild cognitive impairment are of significant importance in delaying the onset of dementia and reducing dementia prevalence. One challenge in these prevention trials is sample recruitment bias. Those willing to volunteer for these trials could be socially active, in relatively good health, and have high educational levels and cognitive function. These participants' characteristics could reduce the generalizability of study results and, more importantly, mask trial effects. We developed a randomized controlled trial to examine whether conversation-based cognitive stimulation delivered through personal computers, a webcam and the internet would have a positive effect on cognitive function among older adults with normal cognition or mild cognitive impairment. To examine the selectivity of samples, we conducted a mass mail-in survey distribution among community-dwelling older adults, assessing factors associated with a willingness to participate in the trial.
Two thousand mail-in surveys were distributed to retirement communities in order to collect data on demographics, the nature and frequency of social activities, personal computer use and additional health-related variables, and interest in the prevention study. We also asked for their contact information if they were interested in being contacted as potential participants in the trial.
Of 1,102 surveys returned (55.1% response rate), 983 surveys had complete data for all the variables of interest. Among them, 309 showed interest in the study and provided their contact information (operationally defined as the committed with interest group), 74 provided contact information without interest in the study (committed without interest group), 66 showed interest, but provided no contact information (interest only group), and 534 showed no interest and provided no contact information (no interest group). Compared with the no interest group, the committed with interest group were more likely to be personal computer users (odds ratio (OR) = 2.78), physically active (OR = 1.03) and had higher levels of loneliness (OR = 1.16).
Increasing potential participants' familiarity with a personal computer and the internet before trial recruitment could increase participation rates and improve the generalizability of future studies of this type.
The trial was registered on 29 March 2012 at ClinicalTirals.gov (ID number NCT01571427).
旨在通过认知刺激预防认知正常或轻度认知障碍者认知能力下降的试验，对于延缓痴呆症发病和降低痴呆症患病率具有重要意义。这些预防试验面临的一个挑战是样本招募偏差。愿意参与这些试验的人可能社交活跃、健康状况相对良好、教育水平高且认知功能良好。这些参与者的特征可能会降低研究结果的普遍性，更重要的是，掩盖试验效果。我们开展了一项随机对照试验，以研究通过个人电脑、网络摄像头和互联网进行的基于对话的认知刺激是否会对认知正常或轻度认知障碍的老年人的认知功能产生积极影响。为了研究样本的选择性，我们在社区居住的老年人中进行了大规模邮寄调查，评估与参与试验意愿相关的因素。
向退休社区发放了2000份邮寄调查问卷，以收集有关人口统计学、社交活动的性质和频率、个人电脑使用情况以及其他与健康相关变量的数据，以及对预防研究的兴趣。我们还询问了如果他们有兴趣作为试验的潜在参与者被联系，其联系信息。
在1102份返回的调查问卷中（回复率为55.1%），983份调查问卷包含了所有感兴趣变量的完整数据。其中，309人表示对研究感兴趣并提供了联系信息（实际定义为有兴趣的参与组），74人提供了联系信息但对研究不感兴趣（无兴趣的参与组），66人表示有兴趣但未提供联系信息（仅感兴趣组），534人表示无兴趣且未提供联系信息（无兴趣组）。与无兴趣组相比，有兴趣的参与组更有可能是个人电脑用户（优势比（OR）=2.78）、身体活跃（OR=1.03）且孤独感水平更高（OR=1.16）。
在试验招募前提高潜在参与者对个人电脑和互联网的熟悉程度，可以提高参与率，并改善此类未来研究的普遍性。
该试验于2012年3月29日在ClinicalTirals.gov上注册（注册号NCT01571427）。
