Dueker Donna, Taher Maryam, Wilson John, McConnell Rob
Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA.
Spatial Sciences Institute, Dana and David Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, USA.
J Expo Sci Environ Epidemiol. 2014 May-Jun;24(3):244-52. doi: 10.1038/jes.2013.11. Epub 2013 Mar 27.
Global positioning system (GPS) technology is increasingly used to assess geographically varying exposure in population studies. However, there has been limited evaluation of accuracy and completeness of personal GPS data. The ability of a GPS data logger to assess location of children during usual activity was evaluated. Data collected for 4 days from 17 children wearing GPS loggers, recorded every 15 s, were evaluated for completeness by time of day during weekend and weekdays, and for accuracy during nighttime at home. Percentage of possible GPS-recorded points and of 5-min intervals with at least one recorded location were examined. Mean percentage of total possible 15-s interval locations recorded daily was less than 30%. Across participants, the GPS loggers recorded 1-47% of total possible location points on weekends and 1-55% on weekdays. More complete data were measured during travel to school (average 91%). The percentage of daily 5-min intervals with recorded data was as high as 53%. At least one location was recorded during 69% of 5-min intervals before school (0630-0800 h), 62% during school (0800-1400 h) and 56% after school (1400-1700 h). During night time (0000-0600 h), on average, location was recorded for less than 25% of 5-min intervals and accuracy was poor. The large proportion of missing data limits the usefulness of GPS logging instruments for population studies. They have potential utility for assessing on-road travel time and route. GPS technology has limitations, and lessons learned from this evaluation can be generalized to the use of GPS in other research settings.
全球定位系统（GPS）技术在人群研究中越来越多地用于评估地理上不同的暴露情况。然而，对个人GPS数据的准确性和完整性的评估有限。评估了GPS数据记录器在儿童日常活动期间评估其位置的能力。对17名佩戴GPS记录器的儿童每隔15秒记录一次、持续4天收集的数据，按周末和工作日的时间段评估其完整性，并在夜间在家时评估其准确性。检查了可能的GPS记录点的百分比以及至少有一个记录位置的5分钟间隔的百分比。每天记录的总可能15秒间隔位置的平均百分比不到30%。在所有参与者中，GPS记录器在周末记录了总可能位置点的1%-47%，在工作日记录了1%-55%。在上学途中测量到的数据更完整（平均91%）。有记录数据的每日5分钟间隔的百分比高达53%。在上学前（06:30-08:00）的5分钟间隔中，69%至少记录了一个位置，在上学期间（08:00-14:00）为62%，放学后（14:00-17:00）为56%。在夜间（00:00-06:00），平均而言，5分钟间隔中记录位置的不到25%，准确性较差。大量缺失数据限制了GPS记录仪器在人群研究中的实用性。它们在评估道路行驶时间和路线方面具有潜在用途。GPS技术存在局限性，从本次评估中吸取的经验教训可推广到GPS在其他研究环境中的应用。
