Bonner Matthew R, Han Daikwon, Nie Jing, Rogerson Peter, Vena John E, Freudenheim Jo L
Department of Social and Preventive Medicine, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
Epidemiology. 2003 Jul;14(4):408-12. doi: 10.1097/01.EDE.0000073121.63254.c5.
Geographic information systems (GIS) offer powerful techniques for epidemiologists. Geocoding is an important step in the use of GIS in epidemiologic research, and the validity of epidemiologic studies using this methodology depends, in part, on the positional accuracy of the geocoding process.
We conducted a study comparing the validity of positions geocoded with a commercially available program to positions determined by Global Positioning System (GPS) satellite receivers. Addresses (N = 200) were randomly selected from a recently completed case-control study in Western New York State. We geocoded addresses using ArcView 3.2 on the GDT Dynamap/2000 U.S. Street database. In addition, we measured the longitude and latitude of these addresses with a GPS receiver. The distance between the locations obtained by these two methods was calculated for all addresses.
The distance between the geocoded point and the GPS point was within 100 m for the majority of subject addresses (79%), with only a small proportion (3%) having a distance greater than 800 m. The overall median distance between GPS points and geocoded points was 38 m (90% confidence interval [CI] = 34-46). Distances were not different for cases and controls. Urban addresses (median = 32 m; CI = 28-37) were slightly more accurate than nonurban addresses (median = 52 m; CI = 44-61).
This study indicates that the suitability of geocoding for epidemiologic research depends on the level of spatial resolution required to assess exposure. Although sources of error in positional accuracy for geocoded addresses exist, geocoding of addresses is, for the most part, very accurate.
地理信息系统（GIS）为流行病学家提供了强大的技术手段。地理编码是在流行病学研究中使用GIS的重要一步，采用这种方法的流行病学研究的有效性部分取决于地理编码过程的位置准确性。
我们开展了一项研究，比较使用市售程序进行地理编码的位置与全球定位系统（GPS）卫星接收器确定的位置的有效性。地址（N = 200）从纽约州西部最近完成的一项病例对照研究中随机选取。我们使用GDT Dynamap/2000美国街道数据库上的ArcView 3.2对地址进行地理编码。此外，我们用GPS接收器测量这些地址的经度和纬度。计算所有地址通过这两种方法获得的位置之间的距离。
大多数研究对象地址（79%）的地理编码点与GPS点之间的距离在100米以内，只有一小部分（3%）的距离大于800米。GPS点与地理编码点之间的总体中位数距离为38米（90%置信区间[CI] = 34 - 46）。病例组和对照组的距离没有差异。城市地址（中位数 = 32米；CI = 28 - 37）比非城市地址（中位数 = 52米；CI = 44 - 61）略准确。
本研究表明，地理编码在流行病学研究中的适用性取决于评估暴露所需的空间分辨率水平。虽然地理编码地址在位置准确性方面存在误差来源，但地址的地理编码在很大程度上非常准确。
