Barker Lawrence E, Luman Elizabeth T, McCauley Mary M, Chu Susan Y
National Immunization Program, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Am J Epidemiol. 2002 Dec 1;156(11):1056-61. doi: 10.1093/aje/kwf149.
Eliminating health disparities in vaccination coverage among various groups is a cornerstone of public health policy. However, the statistical tests traditionally used cannot prove that a state of no difference between groups exists. Instead of asking, "Has a disparity--or difference--in immunization coverage among population groups been eliminated ?," one can ask, "Has practical equivalence been achieved?" A method called equivalence testing can show that the difference between groups is smaller than a tolerably small amount. This paper demonstrates the method and introduces public health considerations that have an impact on defining tolerable levels of difference. Using data from the 2000 National Immunization Survey, the authors tested for statistically significant differences in rates of vaccination coverage between Whites and members of other racial/ethnic groups and for equivalencies among Whites and these same groups. For some minority groups and some vaccines, coverage was statistically significantly lower than was seen among Whites; however, for some of these groups and vaccines, equivalence testing revealed practical equivalence. To use equivalence testing to assess whether a disparity remains a threat to public health, researchers must understand when to use the method, how to establish assumptions about tolerably small differences, and how to interpret the test results.
消除不同群体在疫苗接种覆盖率方面的健康差异是公共卫生政策的基石。然而，传统上使用的统计检验无法证明群体之间不存在差异的状态。与其问“人群组之间在免疫接种覆盖率方面的差异——或差别——是否已消除？”，不如问“是否已实现实际等效性？”一种称为等效性检验的方法可以表明群体之间的差异小于可容忍的少量差异。本文展示了该方法，并介绍了对定义可容忍差异水平有影响的公共卫生考量因素。作者利用2000年全国免疫调查的数据，测试了白人与其他种族/族裔群体成员在疫苗接种覆盖率方面的统计学显著差异，以及白人与这些相同群体之间的等效性。对于一些少数群体和一些疫苗，覆盖率在统计学上显著低于白人；然而，对于其中一些群体和疫苗，等效性检验显示存在实际等效性。为了使用等效性检验来评估差异是否仍然对公共卫生构成威胁，研究人员必须了解何时使用该方法、如何建立关于可容忍小差异的假设以及如何解释测试结果。
