Free access until October 9th, 2019: https://authors.elsevier.com/a/1ZbT5_Uo5A~6R5 

Our commentary answers a systematic review from Lindsey Smith, Louise Foley and Jenna Panther on “Activity spaces in studies of the environment and physical activity” (https://doi.org/10.1016/j.healthplace.2019.04.003)

Thank you Health and Place for this opportunity!

Abstract

Activity space research provides a framework to consider mobility while linking environments to behaviors in the study of neighborhood effects on health. Increased use of wearable location sensors provides new opportunities to observe and analyze fine-grained spatial and temporal information on individuals’ mobility patterns, environmental exposures and behaviors; however, these analysis does not easily translate into causal inference. Additional dimensions underlying behavioral decision-making likely influence or even modify environmental effects on behaviors. This commentary discusses how further progresses in exposure measurement, integration of data collection tools, and development of study designs could support future interventions to optimize how environments shape health profiles and inequities.

Abstract

Purpose

Understanding the geographical and environmental triggers for active transport among older adults is crucial to promote healthy and independent lifestyles. While transportation research has long considered trip purpose as a major determinant of transport mode choices, “place and health” research has paid little attention to it, and even less in connection with environmental determinants. To avoid an oversimplification of how neighborhood built environments influence utilitarian walking, it is critical to account simultaneously for trip purposes, the locations of visited places, and the related exposure to surrounding environments.

Methods

Based on a cohort of 471 older adults in Luxembourg, this study examines the influence of trip purposes on utilitarian walking, and the potential interaction effects with characteristics of multiple geographic environments and distance to the place of residence. Information related to demographics, health status, and regularly visited destinations was collected in 2015 and 2016. Associations between trip purpose, environment, distance, and walking were analyzed using multilevel logistic regressions, accounting for demographics, neighborhood self-selection, and health status.

Results

After accounting for environmental attributes, distance, and confounding factors, trip purpose remained a strong correlate of walking among older adults. Associations between distance and walking strongly differed by trip purpose (Wald Chi2 test p < 0.001). Access to amenities, public transport stops, and street connectivity were associated with walking, although no interaction with trip purpose was observed.

Conclusion

Trip purposes based on free-time activities–including visits to family and friends, and restaurants and cafés–seem to be less influenced by the barrier effect of distance on walking. While place and health studies increasingly address both the “where” and “when” of travel behaviors, the current study additionally stresses the importance of the trip purpose to emphasize “why” and “for what” people walk.

Abstract

Introduction

Promoting active transport offers the potential to increase population physical activity levels. Compensation theories state that above-average physical activity in one activity is compensated in later activities; a mechanism that results in stable levels of total physical activity. Little is known about possible compensation of transport physical activity among older adults.

Methods

GPS (Global Positioning System) and accelerometer data collected among older adults (65+) were pooled from four cohorts in Canada, Luxembourg, and France (n=636, collected between 2012 and 2016). Physical activity was measured as total volume of physical activity for trips and non-trip activities. Robust linear regressions on person-centered data were used to test within-person associations between transport and total physical activity.

Results

636 older adults – median age of 76 years, 49% women – provided accelerometer and GPS data for at least 4 days. 18% of the total volume of physical activity was related to transport. A positive association was found between physical activity during a trip and the physical activity during the next hour, among those with lower levels of regular physical activity. Negative associations – indicating partial compensation – were found between transport physical activity during a day, and both total physical activity during the next day and non-transport physical activity during the same day. No differences were found between the four study cohorts.

Conclusions

Transport physical activity is compensated partially by older adults during non-transport physical activity. Given the presence of compensation, we strongly recommend evaluations of transport interventions to measure and analyze both non-transport and transport physical activity.

I was involved in two talks, one as a presenter and one as a co-author. The talk format was a 5-minute presentation followed by a 3-minutes questions, which may appear very short (especially while preparing your slides), but forces you to give the core message of your study and to leave the rest for informal talks with your peers… Not bad! So the first talk looked at the influence of exposure to multiple environments, trips purposes and distance on utilitarian walking among older adults, based on the CURHA project (soon to be described on this blog). One of the main results stressed the varying barrier effect of distance on walking by trip purpose. People would be more likely to walk with increasing distance to discretionary activity vs. mandatory ones, as they might be more likely to performed these activities in optimal conditions (good weather, good perceived health, having the time to walk…) and thus, discretionary activities are characterized by a higher flexibility in space and time. The second talk, presented by Pr. Jean-Michel Oppert, examined the differential associations of walking and cycling with obesity markers based on the ACTI-Cités project. The related paper was published earlier this year in Obesity Facts (https://doi.org/10.1159/000488532).

I attended mostly sessions looking at the spatial and environmental determinants of physical activity, intervention on physical activity and measurement of physical activity using new technologies. Among these sessions, I would like to report on a couple of talks that especially caught my attention. The first one was a session on “Air pollution and physical activity”, chaired by Dr. Fiona Bull, who immediately brought back the societal and public health issues at stakes: what to answer when the WHO’s phone rings with India on the line to consult on whether they should maintain or not the marathon given the high levels of air pollution? This session mainly addressed whether exposure to air pollution (while doing sport or physical activity) may modify the positive effect of physical activity on health? The answer was pretty clear: long terms benefits of PA among adults are not erased nor reversed by air pollution, so keep being active! On the top of that, Audrey de Nazelle gave a very informative talk on the exposure to air pollution by transport modes. While individuals spend approximatively 6% of their time in travel, it contributes to 24% of NO² inhalation! However, we should keep in mind that in Europe, pedestrians are the least exposed to air pollution compared to car, bus, and bicycle. And pedestrians might be more flexible than other transport mode to choose their travel path towards roads less saturated by car traffic and therefore less polluted. In a session on impact of places and spaces on physical activity, Dr. Jasper Schipperijn presented a ParkIndex tool to measure the exposure to park and predict the probability of an individual at a specific location to use a park. While in their validation study distance did not seem to predict park use, it confirmed me that the influence of “selective daily mobility” on health behaviors cannot be overlooked and should definitively get more attention by the scientific community.

Slide from Dr. Schipperijn on ParkIndex

Finally, innovative tool to visualize exposure to build environment, simulate changes in the urban environment (i.e. school implementation in a neighborhood), and assess related effects on a large number of health related indicators was presented by Dr. Claire Boulange. The power of communication with stakeholders of such a tool is obvious, and appears as a promising complementary method to assess the relevance of urban planning interventions.

Slide from Dr. Boulange on a simulation to assess the impact of implementing a school in a neighborhood

While a lot of other sessions were highly stimulating, I would like to end this report with the very inspiring talk from Richard Wilkinson “Mind the gap: health inequalities”, who made an irrevocable judgement to the case of social inequalities in physical activity and health, and urged each and every individual present at the conference to tackle the structural causes of physical inactivity, starting with socio-economic inequalities.

Brilliant summary of the major determinants of health issues in our society, by Richard Wilkinson