Factorial validity and invariance of a self-report measure of physical activity among adolescent girls

We examined the factorial validity and factorial invariance of the 3-day physical activity recall (3DPAR) using confirmatory factor analysis. Adolescent girls from two cohorts (N = 955, N = 1,797) completed the 3DPAR in the eighth grade; participants in Cohort 2 (N = 1,658) completed the 3DPAR again 1 year later in the ninth grade. The 3DPAR was best represented by two uncorrelated factors in Cohort 1. The two-factor, uncorrelated measurement model exhibited evidence of cross-validity between Cohorts 1 and 2. This model also exhibited configural and partial metric invariance between race and across time. Hence, the 3DPAR consisted of two uncorrelated factors underlying three indicators of both moderate and vigorous physical activity in this sample of Black and White girls across a 1-year period. The 3DPAR can be used in cross-sectional, prospective cohort and intervention studies that examine mediators and moderators of physical activity among Black and White adolescent girls.     

体力活动与多发性硬化症研究的10大问题

摘要：全世界约有250万人患有多发硬化症（MS），并且发病率有增加趋势。MS是一种中枢神经系统疾病，与多种症状和功能障碍相关。目前一线治疗方法对晚期患者基本无效。越来越多的证据表明体力活动（PA）有益于MS患者，但是大多数MS患者存在PA不足和静坐少动行为。因此，我们提出了10个研究问题，旨在指导今后有关PA和MS的研究：1）PA是否是一种MS的缓解性治疗行为？2）PA对MS患者有哪些益处？3）什么样的PA处方最适合MS患者？4）MS患者在PA中有哪些安全问题？5）哪些MS患者可以通过PA获得益处？6）哪些变量可以用来解释PA对MS患者的作用？7）有效促进 MS患者进行PA的行为干预方法是什么？8）我们如何将研究成果用于实际临床工作中？9）静坐少动行为对MS患者有什么影响？10）评价MS患者PA的最佳方法是什么？这些问题对于帮助我们了解PAPA对MS患者长期和短期的效果，开发新方法促进和保持MS患者的PA至关重要，解决这些问题可以大大改善MS患者的生活质量。     

Physical activity and cognitive function in multiple sclerosis

Cognitive impairment is prevalent, disabling, and poorly managed in persons with multiple sclerosis (MS). This cross-sectional study examined the associations among physical activity, cognitive processing speed, and learning and memory in 33 persons with MS who underwent neuropsychological assessments and wore a physical activity monitor for 7 days. Cognitive impairment was greatest in cognitive processing speed. Physical activity was significantly correlated with cognitive processing speed (pr = .35), but not learning and memory (pr = .20), after controlling for sex, age, and education. Researchers should examine exercise training and physical activity effects on cognitive performance, particularly processing speed, in MS.     

Validity of the Marshall Sitting Questionnaire in people with multiple sclerosis

This study examines the validity of the Marshall Sitting Questionnaire (MSQ) in people with multiple sclerosis (MS) and presents a prediction model to improve the accuracy of the MSQ estimates. Participants (n = 63 [15M and 48F], age: 56.6 ± 7.3 years) wore an accelerometer on the hip for a 7-day period and completed the MSQ. Sedentary behaviour (SB) estimates were computed as min/day for both the MSQ and accelerometer. Associations between the two methods were examined using the Pearson correlation and agreement was assessed using a Bland-Altman plot. A linear prediction model was developed to improve the accuracy of the MSQ estimates using a selection of predictor variables routinely collected in MS research. There was a moderate correlation between MSQ and accelerometer SB estimates (r = 0.34, p < 0.01). The Bland-Altman plot indicated that the MSQ overestimated SB (mean bias: 80.54 min/day, 95% limits of agreement: ?410.5 to 571.5 min/day). The prediction model improved the MSQ estimates by 39% and virtually eliminated measurement bias (mean bias:-0.21 min/day; 95% limits of agreement:-109.8 to 109.4 min/day). The results indicate preliminary evidence for the validity of the MSQ in people with MS, and support the application of an alternative prediction model to improve the accuracy of the MSQ estimates.

Abbreviations: SB = sedentary behaviour; MS = multiple sclerosis; MSQ = Marshall Sitting Questionnaire; PA = physical activity; EDSS = Expanded Disability Status Scale; LPA = light physical activity; MVPA = moderate-to-vigorous physical activity; GLTEQ = Godin Leisure Time Exercise Questionnaire; PDDS = Patient-Determined Disease Steps; RMSE = root mean square error.     

Self-Esteem and Method Effects Associated With Negatively Worded Items: Investigating Factorial Invariance by Sex

The Rosenberg Self-Esteem scale (RSE) has been widely used in examinations of sex differences in global self-esteem. However, previous examinations of sex differences have not accounted for method effects associated with item wording, which have consistently been reported by researchers using the RSE. Accordingly, this study examined the multigroup invariance of global self-esteem and method effects associated with negatively worded items on the RSE between males and females. A correlated traits, correlated methods framework for modeling method effects was combined with a standard multigroup invariance routine using covariance structure analysis. Overall, there were few differences between males and females in terms of the measurement of self-esteem and method effects associated with negatively worded items on the RSE. Our findings suggest that, whereas method effects exist on the RSE scale for both males and females, the method effects associated with negatively worded items do not influence the measurement invariance and mean differences in global self-esteem scores between the sexes.     

Reminiscence Effects on Inter- and Intra-Individual Differences in Pursuit Rotor Performance

Abstract

Sixty male college students were given sixty 15-sec. trials on the pursuit rotor learning task. Practice was interrupted halfway through learning by a 10-min. rest period in order to investigate whether or not a reminiscence effect would influence inter-individual differences and intra-individual variation in performance. Results were consistent with previous experimentation in that inter-individual differences increased as a result of both practice and the interpolated rest period. A corresponding effect on intra-individual variation was barely noticeable.