The methods employed to measure behaviour in research testing the theories of reasoned action/planned behaviour (TRA/TPB) within the context of health behaviours have the potential to significantly bias findings. One bias yet to be examined in that literature is that due to common method variance (CMV). CMV introduces a variance in scores attributable to the method used to measure a construct, rather than the construct it represents. The primary aim of this study was to evaluate the impact of method bias on the associations of health behaviours with TRA/TPB variables. Data were sourced from four meta-analyses (177 studies). The method used to measure behaviour for each effect size was coded for susceptibility to bias. The moderating impact of method type was assessed using meta-regression. Method type significantly moderated the associations of intentions, attitudes and social norms with behaviour, but not that between perceived behavioural control and behaviour. The magnitude of the moderating effect of method type appeared consistent between cross-sectional and prospective studies, but varied across behaviours. The current findings strongly suggest that method bias significantly inflates associations in TRA/TPB research, and poses a potentially serious validity threat to the cumulative findings reported in that field.

中文翻译：

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评估方法偏差对健康行为研究的影响：利用理性行为和计划行为理论对研究进行荟萃分析

在健康行为范围内测试理性行为/计划行为理论（TRA / TPB）的研究中，用于测量行为的方法具有显着偏倚结果的潜力。该文献中尚待检验的一种偏见是由于通用方法差异（CMV）而引起的。CMV引入了可归因于该方法的分数差异用于测量构造，而不是其表示的构造。这项研究的主要目的是评估方法偏倚对健康行为与TRA / TPB变量的关联的影响。数据来自四项荟萃分析（177项研究）。对每种效应大小的行为测量方法进行了编码，以考虑偏差的敏感性。使用meta回归评估方法类型的适度影响。方法类型显着缓和了意图，态度和社会规范与行为之间的联系，但没有缓解感知的行为控制与行为之间的联系。方法类型的调节作用的幅度在横断面研究和前瞻性研究之间似乎是一致的，但在行为上有所不同。