Validation of the Block Walk Method for Assessing Physical Activity occurring on Sidewalks/Streets

Untapped Potential of Unobtrusive Observation for Studying Health Behaviors

Improving the environment is an important upstream intervention to promote population health by influencing health behaviors such as physical activity, smoking, and social distancing. Examples of promising environmental interventions include creating high-quality green spaces, building active transport infrastructure, and implementing urban planning regulations. However, there is little robust evidence to inform policy and decision makers about what kinds of environmental interventions are effective and for which populations. In this viewpoint, we make the case that this evidence gap exists partly because health behavior research is dominated by obtrusive methods that focus on studying individual behavior and that are less suitable for understanding environmental influences. In contrast, unobtrusive observation can assess how behavior varies in different environmental contexts. It thereby provides valuable data relating to how environments affect the behavior of populations, which is often useful knowledge for effectively and equitably tackling population health challenges such as obesity and noncommunicable diseases. Yet despite a long history, unobtrusive observation methods are currently underused in health behavior research. We discuss how developing the use of video technology and automated computer vision techniques can offer a scalable solution for assessing health behaviors, facilitating a more thorough investigation of how environments influence health behaviors. We also reflect on the important ethical challenges associated with unobtrusive observation and the use of these emerging video technologies. By increasing the use of unobtrusive observation alongside other methods, we strongly believe this will improve our understanding of the influences of the environment on health behaviors.

The associations between place-based measures of walkability and physical activity across a range of diverse streetscapes

Walkability relates to aspects of a physical environment that have the potential to influence walking in that environment. In 2019, the Environmental Protection Agency developed the National Walkability Index (NWI), an easily accessible, U.S. Census block-group-level indicator of walkability. Although the NWI could be the metric of choice for researchers and urban planners, there is a lack of empirical evidence for its validity. The current study examined the validity of the NWI and Walk Score for predicting physical activity (PA) occurring along urban streetscapes. A wearable video device (Gogloo E7 SMART eyewear) was used to capture videos of streetscapes in 24 U.S. Census block groups in three different sized cities. The block groups varied in walkability, income level, and minority composition. The videos, collected over 10 months during 2019 at different times on weekdays and weekends, were reviewed by experts to obtain counts of walkers/h and individuals performing leisure PA/h (dependent variables). The independent variables were the NWI, its components - transit stop proximity, intersection density, employment/household occupancy mix, and employment mix, and Walk Score. Block group was the level of analysis. Linear regression indicated Walk Score, employment/household occupancy mix, and employment mix were associated with walkers/h (p < .001) while only employment/household occupancy mix, and employment mix were associated with leisure PA/h (p < .001). The NWI did not account for a significant portion of the variance in PA outcomes. A place-based examination of PA and walkability indexes favors the use of Walk Score and a modified version of the NWI.

A comprehensive evaluation of physical activity on sidewalks and streets in three U.S. Cities

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Video-enhanced observation provides objective data on sidewalks/streets activity.

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Neighborhood-level walkability was strongly associated with sidewalks/streets use.

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Most people (67%) were walking; others were sitting, standing, cycling, jogging.

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Sidewalk/street activity varied by time of day, weather, & environmental condition.

A considerable proportion of outdoor physical activity (PA) is done on sidewalks/streets. The purpose of the current study was to create a comprehensive picture of PA and non-PA (sitting and standing) occurring on sidewalks/streets. A wearable video device was used to capture videos during 2019 in three different size (small, medium, large), U.S. cities along 24 observation routes (sidewalks/streets) located in 24 study areas that varied in walkability, income level, and minority composition. Videos were collected over the course of one year during different times of week and weekend days. Expert reviewers examined each video to extract data on counts of people engaged in different types of activities (e.g., walking) per minute of video. A total of 1154 individuals were described in 1237 min of video as either walking (66.9%), sitting/standing (25.7%), jogging (4.2%), cycling (1.8%) or skating/playing (1.4%). A greater number of active people/min were seen in the evening and in the small city (P < 0.05) while more non-PA people/min were observed in the medium city and during the weekend (P < 0.05). Active and non-PA people/min were associated with walkability, income, and minority composition. For instance, in high walkability, low income areas, 3.2 active people/min were observed in areas with a high percentage of non-minority residents compared to 0.9 active people /min in areas with a high percentage of minority residents. Sidewalks/street activities are related to dynamic interactions between social and physical environmental factors. The results of this study may serve as a reference to which future, similar evaluations can compare.

A Direct Observation Video Method for Describing COVID-19 Transmission Factors on a Micro-Geographical Scale: Viral Transmission (VT)-Scan

The COVID-19 pandemic severely affected many aspects of human life. While most health agencies agree mask wearing and physical distancing reduce viral transmission, efforts to improve the assessment of these behaviors are lacking. This study aimed to develop a direct observation video method [Viral Transmission (VT)-Scan] for assessing COVID-19 transmission behaviors and related factors (e.g., environmental setting). A wearable video device (WVD) was used to obtain videos of outdoor, public areas. The videos were examined to extract relevant information. All outcomes displayed good to excellent intra- and inter-reliability with intra-class correlation coefficients ranging from 0.836 to 0.997. The majority of people had a mask (60.8%) but 22.1% of them wore it improperly, 45.4% were not physical distancing, and 27.6% were simultaneously mask and physical distancing non-compliant. Transmission behaviors varied by demographics with white, obese males least likely to be mask-compliant and white, obese females least likely to physical distance. Certain environments (e.g., crosswalks) were identified as "hot spots" where higher rates of adverse transmission behaviors occurred. This study introduces a reliable method for obtaining objective data on COVID-19 transmission behaviors and related factors which may be useful for agent-based modeling and policy formation.