Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK.
Psychol Health. 2013;28(3):234-49. doi: 10.1080/08870446.2012.716838. Epub 2012 Sep 3.
The theory of planned behaviour (TPB) can identify cognitions that predict differences in behaviour between individuals. However, it is not clear whether the TPB can predict the behaviour of an individual person. This study employs a series of n-of-1 studies and time series analyses to examine the ability of the TPB to predict physical activity (PA) behaviours of six individuals. Six n-of-1 studies were conducted, in which TPB cognitions and up to three PA behaviours (walking, gym workout and a personally defined PA) were measured twice daily for six weeks. Walking was measured by pedometer step count, gym attendance by self-report with objective validation of gym entry and the personally defined PA behaviour by self-report. Intra-individual variability in TPB cognitions and PA behaviour was observed in all participants. The TPB showed variable predictive utility within individuals and across behaviours. The TPB predicted at least one PA behaviour for five participants but had no predictive utility for one participant. Thus, n-of-1 designs and time series analyses can be used to test theory in an individual.
计划行为理论（TPB）可以识别出能够预测个体之间行为差异的认知因素。然而，目前尚不清楚 TPB 是否能够预测个体的行为。本研究采用一系列的个体内研究和时间序列分析，来检验 TPB 预测六位个体的身体活动（PA）行为的能力。进行了六项个体内研究，其中 TPB 认知和最多三种 PA 行为（步行、健身房锻炼和个人定义的 PA）在六周内每天测量两次。步行通过计步器的步数进行测量，健身房的出勤情况通过自我报告并结合健身房入场的客观验证进行测量，个人定义的 PA 行为通过自我报告进行测量。所有参与者均观察到 TPB 认知和 PA 行为的个体内变异性。TPB 在个体内和跨行为上的预测效用存在差异。TPB 预测了五名参与者中的至少一种 PA 行为，但对一名参与者没有预测效用。因此，个体内设计和时间序列分析可用于在个体中检验理论。
