Department of Biostatistics, Brown University, Providence, RI 02912, USA.
Health Psychol. 2012 Jul;31(4):512-20. doi: 10.1037/a0026667. Epub 2011 Dec 12.
To examine putative mediators of a 12-month motivationally tailored physical activity (PA) promotion intervention.
We randomly assigned 239 healthy, underactive adults (moderate-vigorous physical activity <90 min/week; mean age = 47.5 years; 82% women) to receive (a) print-based feedback, (b) phone-based feedback, or (c) contact control.
PA at baseline, 6, and 12 months, as measured by the 7-day physical activity recall interview. MEDIATORS: Four TransTheoretical Model constructs explicitly targeted by the intervention (i.e., self-efficacy, decisional balance, cognitive and behavioral processes of change), as well as four additional constructs linked to PA behavior change (i.e., social support, outcome expectancy, PA enjoyment, exercise-induced feelings).
Multivariate mediation analyses were used to analyze longitudinal PA outcomes. Changes in behavioral processes and one aspect of exercise-induced feelings (revitalization) satisfied both action theory (i.e., treatment effects on mediators) and conceptual theory (i.e., mediator effects on PA) tests at 6 and 12 months and emerged as statistically significant mediators of treatment effects on PA across delivery channels (ps <.014). Cognitive processes, self-efficacy, decisional balance, and social support for PA participation satisfied Action Theory tests at both 6 and 12 months, but failed conceptual theory tests. Delayed intervention effects were observed on other aspects of exercise-induced feelings, PA enjoyment, and outcome expectancies, but these variables failed mediation testing at 12 months.
Findings are consistent with previous research illustrating the importance of behavioral processes of change, but also indicate that affective response to PA may warrant more attention as a potential target of behavior change programs.
探讨一项为期 12 个月的动机性量身定制身体活动（PA）促进干预的潜在中介因素。
我们随机分配 239 名健康、活动不足的成年人（中度至剧烈体力活动<90 分钟/周；平均年龄=47.5 岁；82%为女性）接受（a）基于印刷的反馈、（b）基于电话的反馈或（c）接触对照。
通过 7 天体力活动回忆访谈测量的基线、6 个月和 12 个月的 PA。
干预明确针对的四个跨理论模型结构（即自我效能、决策平衡、认知和行为改变过程），以及与 PA 行为改变相关的四个其他结构（即社会支持、预期结果、PA 享受、运动引起的感觉）。
使用多变量中介分析来分析纵向 PA 结果。行为过程的变化和运动引起的感觉的一个方面（恢复活力）在 6 个月和 12 个月时满足了行动理论（即治疗对中介的影响）和概念理论（即中介对 PA 的影响）的测试，并且作为跨传递渠道治疗效果的统计学显著中介因素出现（ps<.014）。认知过程、自我效能、决策平衡和 PA 参与的社会支持在 6 个月和 12 个月时满足行动理论测试，但概念理论测试失败。在运动引起的感觉的其他方面、PA 享受和预期结果方面观察到延迟的干预效果，但这些变量在 12 个月时未能通过中介测试。
研究结果与先前研究一致，表明行为改变过程的重要性，但也表明对 PA 的情感反应可能需要更多关注，作为行为改变计划的潜在目标。
