Comparing GPS, Log, Survey, and Accelerometry to Measure Physical Activity

OBJECTIVES

We explored how objectively measured global positioning system (GPS) and accelerometer data match with travel logs and questionnaires in predicting trip duration and physical activity (PA).

METHODS

99 participants wore GPS devices and accelerometers, and recorded all trips in a log for 5 consecutive days. Participants also completed a self-administered questionnaire on PA and travel behaviors.

RESULTS

There was good agreement between GPS and log for assessment of trip duration, although log measures overestimated trip duration (concordance correlation coefficient 0.53 [0.47, 0.59]; Bland-Altman estimate 0.76 [0.16, 3.71] comparing GPS to log). Log measures underestimated light PA and overestimated moderate PA compared to accelerometry when greater than zero moderate PA was reported.

CONCLUSIONS

It is often not feasible to deploy accelerometry or GPS devices in population research because these devices are expensive and require technical expertise and data processing. Questionnaires and logs provide inexpensive tools to assess PA and travel with reasonable concordance with objective measures. However, they have shortcomings in evaluating the presence and amount of light and moderate PA. Future questionnaires and logs should be developed to evaluate sensitivity to light and moderate PA.

Changes in physical activity and travel behaviors in residents of a mixed-use development

BACKGROUND

Mixed-use developments may be especially promising settings for encouraging walking and other types of physical activity.

PURPOSE

This study examined the physical activity and travel behaviors of individuals before and after they relocated to Atlantic Station, a mixed-use redevelopment community in metropolitan Atlanta.

METHODS

A survey study was conducted to compare the behaviors, experiences, and attitudes of Atlantic Station residents before and after moving to a mixed-use neighborhood. Data were collected in 2008 and 2009 and analyzed in 2010. Key dependent variables were self-reported physical activity and travel behaviors including walking for recreation and transport, automobile use, and use of public transportation.

RESULTS

Study participants included 101 adult residents of Atlantic Station, most of whom were female, young, and well educated. There were significant increases in walking for recreation or fitness (46%-54%; p<0.05) and walking for transportation (44%-84%; p<0.001) after moving into the mixed-use development. Respondents also reported reduced automobile travel and increased time spent using public transportation after moving to Atlantic Station. Because this study used individuals as their own controls, there is more control over confounding lifestyle variables compared to cross-sectional studies of individuals living in different neighborhoods.

CONCLUSIONS

Adults who move to a denser, mixed-use neighborhood increase their levels of walking for both recreation and transportation, decrease their automobile travel, and increase their use of public transportation.

A model curriculum for a course on the built environment and public health: training for an interdisciplinary workforce

Despite growing evidence of the direct and indirect effects of the built environment on public health, planners, who shape the built environment, and public health professionals, who protect the public's health, rarely interact. Most public health professionals have little experience with urban planners, zoning boards, city councils, and others who make decisions about the built environment. Likewise, few planners understand the health implications of design, land use, or transportation decisions. One strategy for bridging this divide is the development of interdisciplinary courses in planning and public health that address the health implications of the built environment. Professional networking and Internet-based searches in 2007 led to the identification of six primarily graduate-level courses in the U.S. that address the links between the built environment and public health. Common content areas in most of the identified courses included planning and public health histories, health disparities, interdisciplinary approaches, air and water quality, physical activity, social capital, and mental health. Instructors of these courses collaborated on course content, assignments, and evaluations to develop a model curriculum that follows an active learning-centered approach to course design. The proposed model curriculum is adaptable by both planning and public health departments to promote interdisciplinary learning. Results show that students gain planning and public health perspectives through this instruction, benefiting from active-learning opportunities. Faculty implementation of the proposed interdisciplinary model curriculum will help bridge the divide between the built environment and public health and enable both planners and public health professionals to value, create, and promote healthy environments.