Behavioural Medicine Laboratory, Faculty of Education, University of Victoria, Victoria, BC, Canada.
Int J Behav Nutr Phys Act. 2010 May 11;7:37. doi: 10.1186/1479-5868-7-37.
An understanding of the determinants of physical activity through mediators of behaviour change is important in order to evaluate the efficacy of interventions. Prior reviews on this topic noted that few studies employed mediator analyses in experimental physical activity trials; the purpose of this review is to update these prior reviews in order to evaluate the state of our present understanding of interventions that include proposed mediators of behaviour change.
Literature was identified through electronic database (e.g., MEDLINE, psychINFO) searching. Studies were eligible if they described a published experimental or quasi-experimental trial examining the effect of an intervention on physical activity behaviour and mediator change in non-clinical adult populations. Quality of included studies was assessed and the analyses examined the symmetry between mediators and behaviour change.
Twenty seven unique trials passed the eligibility criteria and 22 were included in the analysis with scores of moderate or higher quality. Half of the studies reviewed failed to show an intervention effect on PA. The remaining studies showed evidence that the intervention affected changes in the proposed mediators, but tests of mediated effect were performed in only six of these 11 cases and demonstrated mixed outcomes. Differences by theory were not discernable at this time, but self-regulation constructs had the most evidence for mediation.
Published literature employing mediators of change analyses in experimental designs is still relatively elusive since the time of prior reviews; however, the general null findings of changes in mediating constructs from these interventions are a more timely concern. Changes in self-regulation constructs may have the most effect on changes in PA while self-efficacy and outcome expectation type constructs have negligible but limited findings. Innovation and increased fidelity of interventions is needed and should be a priority for future research.
通过行为改变的中介来理解身体活动的决定因素，对于评估干预措施的效果非常重要。此前关于这一主题的综述指出，很少有研究在实验性身体活动试验中采用中介分析；本综述的目的是更新这些先前的综述，以评估我们目前对包括行为改变中介在内的干预措施的理解状态。
通过电子数据库（例如 MEDLINE、psychINFO）搜索来确定文献。如果研究描述了一项已发表的实验性或准实验性试验，该试验检查了干预对非临床成年人群体的身体活动行为和中介变化的影响，则该研究符合入选标准。对纳入研究的质量进行评估，并对分析进行检查，以评估中介和行为变化之间的对称性。
有 27 项独特的试验通过了入选标准，其中 22 项研究被纳入分析，这些研究的质量评分为中等或更高。在审查的研究中，有一半没有显示出干预对 PA 的影响。其余研究表明，干预措施影响了所提出的中介因素的变化，但在这 11 项研究中只有 6 项进行了中介效应的检验，检验结果存在差异。目前还无法看出理论上的差异，但自我调节结构的中介证据最多。
自之前的综述以来，在实验设计中使用中介分析的已发表文献仍然相对难以获得；然而，这些干预措施中中介结构变化的普遍无效结果是一个更及时的关注点。自我调节结构的变化可能对 PA 的变化影响最大，而自我效能和结果预期类型的结构则有微不足道但有限的发现。需要创新和提高干预措施的保真度，这应该是未来研究的优先事项。
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