Department of Kinesiology, The University of Georgia, Ramsey Student Center, 330 River Road, Athens, GA, 30602-6554, USA.
Ann Behav Med. 2010 Oct;40(2):164-75. doi: 10.1007/s12160-010-9208-2.
To test the factorial validity and measurement equivalence/invariance of scales used to measure processes of change derived from the Transtheoretical Model (TTM) applied to physical activity.
Confirmatory factor analysis of questionnaire responses obtained from a diverse sample (N = 1,429) of students enrolled in the Training Interventions and Genetics of Exercise Response (TIGER) Study at the University of Houston during academic years 2004-2005 through 2007-2008. Cohorts of students (N = 1,163) completed the scales at the beginning and end of each Fall semester, permitting longitudinal analysis.
Theoretically and statistically sound models were developed that support the factorial validity of nine of the ten hypothesized 1st-order factors. A structure of nine correlated 1st order factors or a hierarchical structure of those factors subordinate to two correlated 2nd-order factors were each defensible. Multi-group invariance of each model was confirmed across race/ethnicity groups (African American, Hispanic, non-Hispanic White), gender, age, BMI levels, employment status, physical activity level, and study adherence. Longitudinal invariance across the semester was also confirmed.
The scores from the scales provide valid assessments that can be used in observational studies of naturally occurring change or in interventions designed to test the usefulness of TTM processes as mediators of change in physical activity among college students. Item content and factor structure require further evaluation in other samples in order to advance TTM theory applied to physical activity.
测试源自跨理论模型（TTM）应用于身体活动的变化过程的量表的因子有效性和测量等效/不变性。
对休斯顿大学训练干预和运动反应遗传学（TIGER）研究在 2004-2005 学年至 2007-2008 学年期间入学的不同样本（N=1429）的问卷回答进行验证性因子分析。学生队列（N=1163）在每个秋季学期的开始和结束时完成这些量表，允许进行纵向分析。
开发了理论上和统计学上合理的模型，支持了十个假设的一阶因子中的九个的因子有效性。九个相关一阶因子的结构或这些因子从属两个相关二阶因子的层次结构都是合理的。跨种族/族裔群体（非裔美国人、西班牙裔、非西班牙裔白人）、性别、年龄、BMI 水平、就业状况、身体活动水平和研究依从性，每个模型的多组不变性都得到了确认。整个学期的纵向不变性也得到了确认。
这些量表的得分提供了有效的评估，可以用于观察性研究自然发生的变化，也可以用于干预研究，以测试 TTM 过程作为大学生身体活动变化的中介的有用性。为了推进应用于身体活动的 TTM 理论，需要在其他样本中进一步评估项目内容和因子结构。
