Robinson A H, Norman G J, Sallis J F, Calfas K J, Rock C L, Patrick K
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305-5722, USA.
Int J Obes (Lond). 2008 Jul;32(7):1137-44. doi: 10.1038/ijo.2008.65. Epub 2008 May 20.
To investigate the construct, concurrent and predictive validity of stage of change measures for physical activity (PA), and intakes of fruit and vegetables (FVs), dietary fiber (FB) and dietary fat (DF) among a sample of overweight women.
Subjects were 401 women (mean age=41, s.d.=8.7 years; mean body mass index=32.35, s.d.=4.6) recruited to participate in a 12-month weight loss intervention trial. Concurrent validity tests included (1) self-report of current behavior, (2) decisional balance (for example, pros and cons of behavior change), (3) self-efficacy, (4) the MTI Actigraph accelerometer (for the PA staging measure), and (5) a food-frequency questionnaire (for all dietary staging measures). Predictive validity was assessed through tests of the relationship between the baseline stage of change measures and their corresponding behavior 1-year later.
Coefficient alpha-tests of internal consistency exceeded 0.70 on the majority of scales. Concurrent validity tests indicated strong validity evidence for three staging measures and little validity for the DF staging measure (eta(2) range, 0.02-0.18). All staging algorithms demonstrated predictive validity (eta(2) range, 0.04-0.126).
Staging measures can determine motivational readiness for overweight women, contribute to the standardization of stage of change assessment and facilitate cross-study comparisons.
在超重女性样本中，研究身体活动（PA）、水果和蔬菜摄入量（FVs）、膳食纤维（FB）和膳食脂肪（DF）的行为改变阶段测量的结构效度、同时效度和预测效度。
401名女性（平均年龄 = 41岁，标准差 = 8.7岁；平均体重指数 = 32.35，标准差 = 4.6）被招募参加一项为期12个月的减肥干预试验。同时效度测试包括：（1）当前行为的自我报告；（2）决策平衡（例如，行为改变的利弊）；（3）自我效能感；（4）MTI Actigraph加速度计（用于PA阶段测量）；（5）食物频率问卷（用于所有饮食阶段测量）。通过测试行为改变阶段测量的基线阶段与其1年后相应行为之间的关系来评估预测效度。
大多数量表的内部一致性系数α检验超过0.70。同时效度测试表明，三种阶段测量有很强的效度证据，而DF阶段测量效度证据不足（η²范围为0.02 - 0.18）。所有阶段划分算法均显示出预测效度（η²范围为0.04 - 0.126）。
阶段测量可以确定超重女性的动机准备程度，有助于行为改变阶段评估的标准化，并便于进行跨研究比较。
