Department of Epidemiology and Public Health, University College London, England.
J Am Dent Assoc. 2010 Feb;141(2):143-9. doi: 10.14219/jada.archive.2010.0131.
The aim of this study was to assess the correlates of income and income inequality with dental caries in a sample of all countries, as well as in rich countries alone.
In this ecological study, the authors analyzed national data on income, income inequality and dental caries from 48 countries. Of them, 22 were rich countries (according to World Bank criteria). The authors determined income by gross national income (GNI) per capita (formerly known as gross national product) and income inequality by the Gini coefficient (a measure of income inequality on a scale between 0 and 1). They assessed dental caries according to the decayed, missing, filled teeth (dmft) index in 5- to 6-year-old children. The authors used Pearson and partial correlation coefficients to examine the linear associations of income and income inequality with dental caries.
GNI per capita, but not the Gini coefficient, was inversely correlated with the dmft index in the 48 countries. However, the results showed an opposite pattern when analyses were restricted to rich countries (that is, the dmft index was significantly correlated with the Gini coefficient but not with GNI per capita).
These findings support the income inequality hypothesis that beyond a certain level of national income, the relationship between income and the population's health is weak. Income inequality was correlated more strongly with dental caries than was income in rich countries.
Among rich countries, income inequality is a stronger determinant of childhood dental caries than is absolute income.
本研究旨在评估收入和收入不平等与所有国家以及富裕国家样本中龋齿的相关性。
在这项生态研究中，作者分析了来自 48 个国家的关于收入、收入不平等和龋齿的数据。其中，22 个是富裕国家（根据世界银行的标准）。作者通过人均国民总收入（GNI）（以前称为国民生产总值）来确定收入，通过基尼系数（衡量收入不平等程度的指标，范围在 0 到 1 之间）来确定收入不平等。他们根据 5-6 岁儿童的龋齿、缺失、补牙（dmft）指数评估龋齿。作者使用 Pearson 和偏相关系数来检验收入和收入不平等与龋齿之间的线性关联。
人均 GNI 与 48 个国家的 dmft 指数呈负相关，但基尼系数没有。然而，当分析仅限于富裕国家时，结果显示出相反的模式（即 dmft 指数与基尼系数显著相关，而与人均 GNI 无关）。
这些发现支持收入不平等假说，即在一定的国家收入水平之上，收入与人口健康之间的关系较弱。在富裕国家，收入不平等与龋齿的相关性强于收入。
在富裕国家中，收入不平等是儿童龋齿的一个更强决定因素，而不是绝对收入。
