McVay Megan A, King Heather A, Jeffreys Amy S, Coffman Cynthia J, Voils Corrine I
a Center for Health Services Research in Primary Care , Durham VA Medical Center , Durham , NC 27705 , USA.
Psychol Health Med. 2015;20(7):753-66. doi: 10.1080/13548506.2015.1020817. Epub 2015 Mar 16.
Spouse-assisted interventions can improve health behaviors, but mechanisms of action are unknown. This study evaluated mediators of dietary and physical activity outcomes during a spouse-assisted intervention to improve low-density lipoprotein cholesterol. This is a secondary analysis of data from a randomized controlled trial comparing usual care (n = 128) to a spouse-assisted lifestyle change intervention (n = 127) comprising nine monthly goal setting telephone calls to participants and support planning calls to spouses over 11 months. Structural equation modeling was used to examine if the intervention influenced the putative mediators of participant self-efficacy and perceived spousal support at 6 months (i.e. action test); if changes in putative mediators at 6 months were associated with changes in diet and physical activity outcomes at 11 months (i.e. conceptual test); and if treatment condition effects on outcomes at 11 months were mediated by its effects on the 6-month putative mediators (i.e. indirect effects test). Participants were 94.9% male, 64.9% white and were 61.3 years old on average. The action test showed that the intervention increased dietary self-efficacy (p < .001) and perceived spousal support for diet (p < .001) and physical activity (p < .01) at 6 months. The conceptual test showed that increases in participant physical activity self-efficacy at 6 months were associated with increases in physical activity frequency (p = .01) and duration (p = .04) at 11 months; other putative mediators were not associated with changes in outcomes at 11 months. The indirect effects tests did not support a mediating role for self-efficacy or perceived spousal support. Intervention-induced changes in spousal support and dietary self-efficacy did not translate into behavior change. Other mechanisms may be driving behavior change.
配偶辅助干预可以改善健康行为，但作用机制尚不清楚。本研究评估了在配偶辅助干预以改善低密度脂蛋白胆固醇期间，饮食和身体活动结果的中介因素。这是一项对随机对照试验数据的二次分析，该试验将常规护理（n = 128）与配偶辅助生活方式改变干预（n = 127）进行比较，后者包括在11个月内每月给参与者打9次目标设定电话，并给配偶打支持计划电话。采用结构方程模型来检验干预是否在6个月时影响参与者自我效能感和感知到的配偶支持这些假定的中介因素（即行动测试）；6个月时假定中介因素的变化是否与11个月时饮食和身体活动结果的变化相关（即概念测试）；以及11个月时治疗条件对结果的影响是否通过其对6个月时假定中介因素的影响来介导（即间接效应测试）。参与者中94.9%为男性，64.9%为白人，平均年龄为61.3岁。行动测试表明，干预在6个月时提高了饮食自我效能感（p < .001）以及感知到的配偶对饮食（p < .001）和身体活动（p < .01）的支持。概念测试表明，6个月时参与者身体活动自我效能感的提高与11个月时身体活动频率（p = .01）和时长（p = .04）的增加相关；其他假定的中介因素与11个月时结果的变化无关。间接效应测试不支持自我效能感或感知到的配偶支持的中介作用。干预引起的配偶支持和饮食自我效能感的变化并未转化为行为改变。可能有其他机制驱动行为改变。
