Constructing indices representing supportiveness of the physical environment for walking using the Rasch measurement mod
- PDF / 752,957 Bytes
- 13 Pages / 610 x 792 pts Page_size
- 94 Downloads / 172 Views
BioMed Central
Open Access
Methodology
Constructing indices representing supportiveness of the physical environment for walking using the Rasch measurement model Gavin R McCormack*1, Louise C Mâsse2, Max Bulsara1, Terri J Pikora1 and Billie Giles-Corti1 Address: 1School of Population Health, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia and 2Department of Pediatrics, The University of British Columbia, Centre for Community Child Health Research, 4480 Oak St., L408, Vancouver, British Columbia, V5H 3V4, Canada Email: Gavin R McCormack* - [email protected]; Louise C Mâsse - [email protected]; Max Bulsara - [email protected]; Terri J Pikora - [email protected]; Billie Giles-Corti - [email protected] * Corresponding author
Published: 16 December 2006 International Journal of Behavioral Nutrition and Physical Activity 2006, 3:44 5868-3-44
doi:10.1186/1479-
Received: 13 June 2006 Accepted: 16 December 2006
This article is available from: http://www.ijbnpa.org/content/3/1/44 © 2006 McCormack et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract Background: The objectives of this study were to use the Rasch model to 1) assess the psychometric properties of a physical environmental audit instrument and 2) to develop indices of interrelated environmental attributes that summarize environmental supportiveness for walking. Methods: A set of items were derived representing two conceptual physical environmental constructs: 1) functional/safety, and; 2) aesthetics. Ad hoc criteria based on point-biserial and Raschbased fit statistics were used to examine the construct validity and internal reliability of the two constructs. Results: The Rasch-based fit statistics assisted in identifying 12 items that belonged to the functional/safety construct and 4 items that belonged to the aesthetic construct. The reliability of the two constructs were low to moderate (functional/safety rβ = 0.19 and aesthetics rβ = 0.35). Conclusion: Given the vast number of built environmental attributes, a means of developing summary indices is essential. Future studies should assess the reliability and validity of indices that summarize physical environmental characteristics conducive to walking before testing them in predictive models of physical activity. More research examining procedures for measuring the built environment and techniques for analyzing environmental data are needed to guide future research in this area.
Background In the past decade, understanding the impact of the physical environment on physical activity has become a topic of increasing interest. Recent reviews have highlighted characteristics of the physical environment associated with physical activity behaviors [1-3]. To date measures of
th
Data Loading...
