Lippke Sonia, Ziegelmann Jochen P, Schwarzer Ralf, Velicer Wayne F
Department of Psychology, Freie Universitat Berlin, Berlin, Germany.
Health Psychol. 2009 Mar;28(2):183-93. doi: 10.1037/a0012983.
Stage assessments are examined to develop and test refined measurements that can be used for classifying individuals.
Stages were assessed in 1,850 persons in terms of their physical activity and dietary behaviors.
Stages for both behaviors were compared to behavior and other test variables. Misclassification, sensitivity, specificity, receiver-operation-curves, and discontinuity patterns were computed. Discontinuity patterns were tested with trends across stages and planned contrasts between adjacent stages.
In comparison to previous studies, sensitivity (70% to 80%) and specificity (80% to 87%) were high. When using lower level criteria (such as less intensive activity), sensitivity was lower, whereas specificity was higher. When behavioral maintenance was assessed, results suggested that the temporal cut-off point between action and maintenance was equally optimal at different cut-off points. Applying contrast analyses, nonlinear trends across the stages and a match of 87% of predictions of stage differences resulted.
Stage assumptions are supported in general, and refined stage assessment in particular. Levels of psychological variables (e.g., easiness, habit) may discriminate stages as well as or even better than temporal stage definitions.
对阶段评估进行研究，以开发和测试可用于个体分类的优化测量方法。
根据1850人的身体活动和饮食行为对阶段进行评估。
将两种行为的阶段与行为及其他测试变量进行比较。计算错误分类、敏感性、特异性、受试者工作特征曲线和不连续模式。通过各阶段的趋势以及相邻阶段之间的计划对比来测试不连续模式。
与先前的研究相比，敏感性（70%至80%）和特异性（80%至87%）较高。使用较低水平的标准（如强度较低的活动）时，敏感性较低，而特异性较高。在评估行为维持情况时，结果表明行动与维持之间的时间分界点在不同的分界点处同样最佳。应用对比分析，得出了各阶段的非线性趋势以及87%的阶段差异预测匹配度。
总体上支持阶段假设，特别是优化的阶段评估。心理变量水平（如轻松程度、习惯）在区分阶段方面可能与时间阶段定义一样好甚至更好。
