Background
Residence in neighborhoods where streets are safe, attractive, and connected has been related to physical activity (PA).[1,2] Research has focused more on adults and has been conducted in high income countries.[3] This relationship is as yet undocumented in most low and middle income countries, such as Mexico, an emerging influence on North American countries, and burdened with the highest childhood obesity rate in the world. Specific types of environmental factors might influence particular types of PA (eg, recreational, transportation) differently;[4] however, many of these findings are based on perceived or resident self-reported environmental variables with few studies using objective, in-person audits of the environment.

Objectives
This study investigated the relationship of objectively assessed street scale data with PA among Mexican children.

Methods
Neighborhoods were an 800 meter radial buffer circumscribed[5] around public schools selected by the State of Jalisco Secretary of Education (Guadalajara n=12; Puerto Vallarta n=5) or from another study of policy implementation in Mexico (Mexico City n=18). Trained American and Mexican field assessors measured5 25% of residential and all arterial street segments[3] within the radial buffer were coded using an adapted version of the Pedestrian Environment Data Scan.[6] Traffic buffers (eg, fence, trees, grass), path connections, traffic control devices, traffic lanes, crossing aids, amenities (eg, benches, trash cans, street vendors), bicycle facilities and traffic speed limit were measured to represent street scale features. Assessments were conducted in teams of at least 2 people following established data collection and safety protocols.[5, 6]   Mexican school children participated in a multisite investigation of neighborhood and health in Mexican school children in Guadalajara (n=804), Mexico City (n=703) and Puerto Vallarta (n=207) in 2012. Demographic characteristics of child’s age, gender, and the number of children in the home and PA were measured using a translated version of the 4th grade School Physical Activity and Nutrition (SPAN) survey that was distributed to parents for completion.[7] Parents completed items measuring the days of outdoor play, participation on sports teams (yes/no) and participation in other organized PA (yes/no).[8] Children provided assent and parents provided consent following approved IRB protocols.   Descriptive, bivariable analyses were conducted using correlation, t, one-way ANOVA or Chi Square tests. Initial bivariable associations (correlations) conducted for PEDS variables determined high multicollinearity; therefore, each PEDS variable was tested in a separate model for each of the three PA outcomes. Street segment data were aggregated to the neighborhood level by taking the mean across street segments for each neighborhood, using established protocols for ecologic analyses.[9] Hierarchical regression models were used to estimate the effect of aggregated environmental factors on individual days played outside, and hierarchical logistic regression models were used to determine associations with participation in sports teams and other organized physical activities. All models were controlled for individual child age, gender, number of children in household, and city of residence.

Results
The sample (M=9.6±1.0 years) was nearly evenly divided by gender (n=817 boys, 46.9%; n= 924 girls, 53.1%), with an average of 2.5±1.6 children per household. On average, parents reported that their child played outdoors for 30 minutes about twice a week (M=2.4±2.3), nearly half participated in at least one sports team (n=619, 47.2%) and over one third participated in other organized physical activities (n=566, 40.6%). Gender was consistently associated with PA participation, with girls spending fewer days playing outdoors (m=2.1±2.1 vs.  m=2.6±2.3, p

Conclusions
Outdoor play may occur on streets with fewer street elements that focus on pedestrian safety and comfort (buffers, connectivity, crossing aids, amenities), on streets that may have less traffic (fewer lanes, control devices). Perhaps these are quieter streets with less traffic and fewer pedestrian enhancements. Participation in sports and other organized activities was related to few neighborhood variables. Participating in other organized activities was associated with having more children in the household (not shown). Perhaps participation in extracurricular activities is driven by time and access to resources.

Implications
The lower levels of participation in play, sports and other activities suggest that strategies at all levels are needed to increase PA among Mexican children. Increasing access to safe and pleasant areas in neighborhoods may help to increase PA.

References

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3. Giles-Corti B, Kelty SF, Zubrick SR, Villanueva KP. Encouraging walking for transport and physical activity in children and adolescents: how important is the built environment? Sports Med. 2009;39(12):995-1009. doi: 10.2165/11319620-000000000-00000. Review. PubMed PMID: 19902982. http://www.ncbi.nlm.nih.gov/pubmed/19902982.
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7. Thiagarajah K, Fly AD, Hoelscher DM, Bai Y, Lo K, Leone A, Shertzer JA. Validating the food behavior questions from the elementary school SPAN questionnaire. J Nutr Educ Behav. 2008 Sep-Oct;40(5):305-10. doi: 10.1016/j.jneb.2007.07.004. PubMed PMID: 18725149.
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9. Heinrich KM, Lee RE, Suminski RR, Regan GR, Reese-Smith JY, Howard HH, Haddock CK, Poston WS, Ahluwalia JS. Associations between the built environment and physical activity in public housing residents. Int J Behav Nutr Phys Act. 2007;4:56.

Support / Funding Source
This work made possible by a Fulbright-García Robles Core Scholar Fellowship awarded to Dr. Lee, the Canadian Institutes for Health Research and the Public Health Agency of Canada.