Institute of Biopharmaceutical Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
BMC Public Health. 2011 May 24;11:380. doi: 10.1186/1471-2458-11-380.
Geographic Information Systems (GIS) combined with spatial analytical methods could be helpful in examining patterns of drug use. Little attention has been paid to geographic variation of cardiovascular prescription use in Taiwan. The main objective was to use local spatial association statistics to test whether or not the cardiovascular medication-prescribing pattern is homogenous across 352 townships in Taiwan.
The statistical methods used were the global measures of Moran's I and Local Indicators of Spatial Association (LISA). While Moran's I provides information on the overall spatial distribution of the data, LISA provides information on types of spatial association at the local level. LISA statistics can also be used to identify influential locations in spatial association analysis. The major classes of prescription cardiovascular drugs were taken from Taiwan's National Health Insurance Research Database (NHIRD), which has a coverage rate of over 97%. The dosage of each prescription was converted into defined daily doses to measure the consumption of each class of drugs. Data were analyzed with ArcGIS and GeoDa at the township level.
The LISA statistics showed an unusual use of cardiovascular medications in the southern townships with high local variation. Patterns of drug use also showed more low-low spatial clusters (cold spots) than high-high spatial clusters (hot spots), and those low-low associations were clustered in the rural areas.
The cardiovascular drug prescribing patterns were heterogeneous across Taiwan. In particular, a clear pattern of north-south disparity exists. Such spatial clustering helps prioritize the target areas that require better education concerning drug use.
地理信息系统（GIS）与空间分析方法相结合，有助于研究药物使用模式。然而，目前对台湾地区心血管药物处方使用的地域差异关注较少。本研究旨在利用局部空间关联统计检验台湾 352 个乡镇的心血管药物处方模式是否具有同质性。
本研究采用全局指标莫兰指数（Moran's I）和局部空间关联指标（LISA）进行统计分析。莫兰指数提供了数据整体空间分布的信息，而 LISA 则提供了局部空间关联类型的信息。LISA 统计还可用于识别空间关联分析中的影响点。主要的心血管药物处方类别取自台湾全民健康保险研究数据库（NHIRD），该数据库的覆盖率超过 97%。处方的剂量均转换为特定日剂量，以衡量每类药物的使用量。数据在乡镇层面上利用 ArcGIS 和 GeoDa 进行分析。
LISA 统计显示，南部乡镇存在异常的心血管药物使用情况，且存在较高的局部变异。药物使用模式也显示出更多的低-低空间聚类（冷点）而非高-高空间聚类（热点），这些低-低关联聚类主要集中在农村地区。
台湾地区的心血管药物处方模式存在异质性。特别是存在明显的南北差异。这种空间聚类有助于确定需要加强药物使用教育的重点地区。
