Individual and Environmental Mechanisms of PA Change

描述(由申请人提供)： 关于体力活动(PA)干预有效性的机制和潜在的调节因素，目前还缺乏信息。了解PA变化的机制将有助于成功地制定干预措施，同时了解主持人，并使干预措施的组成部分与特定人群的个人需求相匹配。为了明确了解行为改变的机制和调节因素，有必要制定基于理论的干预措施，其中包括针对拟议的改变机制的具体策略，同时在干预前后监测拟议的中介和调节变量。该提案强调使用体力活动生态模型(EMPA)作为制定战略的理论指南。EMPA强调了在制定和实施干预措施时处理个人(生物和心理社会)和环境变量(例如，PA资源可获得性)的必要性。被转介进行跑步机心血管压力测试的健康护理患者--但在测试过程中没有出现异常的心电图或胸痛--将根据低心率恢复的诊断进行分层，这是干预效果的潜在生物调节因素。为了检验个体动机和环境可及性的潜在独立效应和联合效应，我们将进行随机2×2析因试验，以检验所提出的有效性中介变量。参与者(n=500)将被随机分为个人(I)、环境(E)、组合(L+E)或匹配的接触性营养控制。所有干预条件将包括一次光盘会议、3封定制邮件和3次定制的自动化电话随访，为期6个月。我们将评估这些干预措施的覆盖范围、有效性、临床医生采用率和工作人员实施情况，包括单独评估、联合评估，并与研究不足和高需求人群的对照进行比较。这些人群是风险较高但尚未发生严重心脏事件的人群(美国每年约有300万人)。该项目的结果将确定PA变化的环境和个体调解者之间的因果关系和潜在的相加关系，并允许检查潜在的生物调节剂的有效性。由于干预的效果通常会随着时间的推移而减少，而且研究没有解决确保组织层面交付的可持续性所必需的与环境相关的问题，因此我们将在干预后6个月和12个月确定对因果机制和PA的干预效果的维持。这些干预措施将由典型的医务人员在跑步机压力测试的常规范围内进行，并对每种干预条件下的提供费用进行评估。这一项目独特地利用了一些方法，这些方法将有助于在成功完成试验并可能在其他保健环境中采用干预措施后，将干预措施部分制度化。

DESCRIPTION (provided by applicant): There is a dearth of information on the mechanisms, and potential moderators, of physical activity (PA) intervention effectiveness. Understanding the mechanisms of PA change will aid in successful intervention development while understanding moderators and will allow a matching of intervention components to individual needs of particular populations. To definitively understand mechanisms and moderators of behavior change it is necessary to develop theory-based interventions that include specific strategies that target proposed mechanisms of change while monitoring the proposed mediating and moderating variables prior to and following intervention. This proposal highlights the use of the Ecological Model of Physical Activity (EMPA) as a theoretical guide to strategy development. The EMPA highlights the necessity to address individual (biological & psychosocial) and environmental variables (e.g., PA resource accessibility) when developing and implementing interventions. Health care patients who have been referred for a treadmill cardiovascular stress test--but do not present abnormal ECG or chest pain during testing-will be will be stratified by diagnosis of low heart rate recovery, a potential biological moderator of intervention effectiveness. To detect the potential independent and combined effects of individual motivation and environmental accessibility we will conduct a randomized 2X2 factorial trial to test proposed mediators of effectiveness. Participants (n=500) will be randomized to an individual (I), environmental (E), combination (l+E), or matched contact nutrition control. All intervention conditions will include a CD-ROM session, 3 tailored mail, and 3 tailored automated telephone follow-ups over a 6-month period. We will assess the reach, effectiveness, clinician adoption, and staff implementation of these interventions, individually, in combination, and when compared to controls among an understudied and high need population--individuals who are at an elevated risk, but have not yet suffered a serious cardiac event (approximately 3,000,000 individuals/year in the US). The results of this project will identify the causal, and potentially additive, relationships of environmental and individual mediators of PA change and allow the examination of potential biological moderators of effectiveness. Because intervention typically effects decrease over time and studies do not address setting-related issues necessary to ensure sustainability of delivery at the organizational level we will determine the maintenance of intervention effects on causal mechanisms and PA, 6 & 12 months following intervention. The interventions will be developed for delivery within the regular scope of treadmill stress testing by typical medical staff and cost of delivery will be assessed for each intervention condition. This project uniquely utilizes methods that will facilitate institutionalization of the intervention components following the successful completion of the trial and potential adoption of the intervention in other health care settings.