Minnesota Department of Health, 85 East 7th Place, St. Paul, MN 55164-0882, USA.
Cancer Causes Control. 2012 Jun;23(6):791-805. doi: 10.1007/s10552-012-9920-2. Epub 2012 Apr 11.
The study of the geographical distribution of disease has expanded greatly with GIS technology and its application to increasingly available public health data. The emergence of this technology has increased the challenges for public health practitioners to provide meaningful interpretations for county-based state cancer maps.
One of these challenges-spurious inferences about the significance of differences between county and overall state cancer rates-can be addressed through a nonparametric statistical method. The Wilcoxon's signed rank test (WSRT) has a practical application for determining the significance of county cancer rates compared to the statewide rate. This extension of the WSRT, developed by John Tukey, forms the basis for constructing a single confidence interval for all differences in county and state directly age-adjusted cancer rates. Empirical evaluation of this WSRT application was conducted using Minnesota cancer incidence data.
The WSRT procedure reduced the impact of statistical artifacts that are frequently encountered with standard normal significance testing of the difference between directly age-adjusted county and the overall state cancer rates.
Although further assessment of its performance is required, the WSRT procedure appears to be a useful complement for mapping directly age-adjusted state cancer rates by county.
随着 GIS 技术及其在越来越多公共卫生数据中的应用，疾病的地理分布研究得到了极大的扩展。这项技术的出现增加了公共卫生从业者的挑战，他们需要对基于县的州癌症地图进行有意义的解释。
这些挑战之一是——对县和全州癌症发病率之间差异的显著性的错误推断——可以通过一种非参数统计方法来解决。Wilcoxon 的符号秩检验（WSRT）在确定县癌症发病率与全州发病率之间的差异显著性方面具有实际应用价值。约翰·图基（John Tukey）对 WSRT 进行了扩展，形成了一种构建所有县和州直接年龄调整后癌症发病率差异的单一置信区间的基础。使用明尼苏达州癌症发病率数据对这种 WSRT 应用进行了实证评估。
WSRT 程序减少了在对县和全州直接年龄调整后癌症发病率进行标准正态显著性检验时经常遇到的统计假象的影响。
尽管需要进一步评估其性能，但 WSRT 程序似乎是按县映射直接年龄调整后的州癌症发病率的有用补充。
