Abstract. National trends indicate that children and adolescents are not achieving sufficient levels of physical activity. Combining global positioning system (GPS) technology with accelerometers has the potential to provide an objective determination in locations where youth engage in physical activity. The aim of this study was to identify the optimal methods for collecting combined accelerometer and GPS data in youth, to best locate where children spend time and are physically active. A convenience sample of 24 mid-school children in Massachusetts was included. Accelerometers and GPS units were used to quantify and locate childhood physical activity over 5 weekdays and 2 weekend days. Accelerometer and GPS data were joined by time and mapped with a geographical information system (GIS) using ArcGIS software. Data were collected in winter, spring, summer in 2009-2010, collecting a total of 26,406 matched datapoints overall. Matched data yield was low (19.1% total), regardless of season (winter, 12.8%; spring, 30.1%; summer, 14.3%). Teacher-provided, pre-charged equipment yielded the most matched (30.1%; range: 10.1-52.3%) and greatest average days (6.1 days) of data. Across all seasons, children spent most of their time at home. Outdoor use patterns appeared to vary by season, with street use increasing in spring, and park and playground use increasing in summer. Children spent equal amounts of physical activity time at home and walking in the streets. Overall, the various methods for combining GPS and accelerometer data provided similarly low amounts of combined data. No combined GPS and accelerometer data collection method proved superior in every data return category, but use of GIS to map joined accelerometer and GPS data can demarcate childhood physical activity locations.

BackgroundPhysical activity is a health-enhancing behavior, but few adolescents achieve the recommended levels of moderate-to-vigorous physical activity. Understanding how adolescents use different built environment spaces for physical activity and activity varies by location could help in designing effective interventions to promote moderate-to-vigorous physical activity. The objective of this study was to describe the locations where adolescents engage in physical activity and compare traditional intensity-based measures with continuous activity when describing built environment use patterns among adolescents.MethodsEighty adolescents aged 11–14 years recruited from community health and recreation centers. Adolescents wore accelerometers (Actigraph GT3X) and global positioning system receivers (QStarz BT-Q1000XT) for two separate weeks to record their physical activity levels and locations. Accelerometer data provided a continuous measure of physical activity and intensity-based measures (sedentary time, moderate-to-vigorous physical activity). Physical activity was mapped by land-use classification (home, school, park, playground, streets & sidewalks, other) using geographic information systems and this location-based activity was assessed for both continuous and intensity-based physical activity derived from mixed-effects models which accounted for repeated measures and clustering effects within person, date, school, and town.ResultsMean daily moderate-to-vigorous physical activity was 22 minutes, mean sedentary time was 134 minutes. Moderate-to-vigorous physical activity occurred in bouts lasting up to 15 minutes. Compared to being at home, being at school, on the streets and sidewalks, in parks, and playgrounds were all associated with greater odds of being in moderate-to-vigorous physical activity and achieving higher overall activity levels. Playground use was associated with the highest physical activity level (β = 172 activity counts per minute, SE = 4, p < 0.0001) and greatest odds of being in moderate-to-vigorous physical activity (odds ratio 8.3, 95% confidence interval 4.8-14.2).ConclusionAdolescents were more likely to engage in physical activity, and achieved their highest physical activity levels, when using built environments located outdoors. Novel objective methods for determining physical activity can provide insight into adolescents’ spatial physical activity patterns, which could help guide physical activity interventions. Promoting zoning and health policies that encourage the design and regular use of outdoor spaces may offer another promising opportunity for increasing adolescent physical activity.

No abstract

BACKGROUND Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) need access to specialized care. We hypothesized that access to the transplant center after HSCT may be challenging for patients living in geographically distant areas, and that this would have an adverse effect on their outcome. METHODS We analyzed 1912 adult patients who underwent allogeneic HSCT at DF/BWCC between 1996 and 2009 and who resided within 6 hours driving time of the institution. Driving time from primary residence to DF/BWCC based on zipcode was determined using geographic information systems. RESULTS The median driving time (range) to DF/BWCC was 72 (2-358) minutes. When patients were stratified by driving time quartile, overall survival (OS) after HSCT was similar in the first year but worse after 1 year in patients in the top quartile (≥160 minutes driving time). In a landmark analysis of the 909 patients alive and free of disease at 1 year, 5-yr OS was 76% and 65% for patients in the 1st (≤40 minutes) and 4th (≥160 minutes) quartiles, respectively (p=0.027). This was confirmed in a multivariable analysis. The difference appeared to be mostly due to an increase in non-relapse mortality. The number of visits to the transplant center between day 100 and 365 after HSCT declined significantly with increasing driving time to the transplant center, which was independently associated with worse survival. CONCLUSION Long driving time to the transplant center is associated with worse OS in patients alive and disease-free one year after HSCT, independently of other patient-, disease- and HSCT related variables. This may be in part related to the lower frequency of post-HSCT visits in patients living farther away.

Utilization of surgical services was low and inversely related to distance from residence to hospital in rural areas of central Haiti. Children and patients receiving obstetric, gynecologic or emergent surgery lived significantly closer to the hospital, and these groups may need special attention to ensure adequate access to surgical care.