Schneider M C, Castillo-Salgado C, Loyola-Elizondo E, Bacallao J, Mujica O J, Vidaurre M, Alleyne G A O
Special Program for Health Analysis, Pan American Health Organisation, World Health Organisation, Washington, DC 20037-2825, USA.
J Epidemiol Community Health. 2002 Jul;56(7):538-41. doi: 10.1136/jech.56.7.538.
s: To describe overall and income related trends in infant mortality inequalities in the Region of the Americas from 1955 to 1995.
Infant mortality rates (IMRs) were computed and their trends assessed by ordinary least squares. Overall trends in IMR inequalities among countries were analysed by comparing 10 year period IMRs, Gini coefficients, and Lorenz curves. Income related trends in IMR inequalities were assessed using 10 year period IMR ratios between the highest and the lowest quintiles of the per capita gross national product (GNP) distributions (adjusted for purchasing power).
Aggregated country data were used for all countries with over 200 thousand inhabitants (33 geopolitical units). The 10 year period midpoint IMR estimates used for the 1955-1995 time series were those published by the United Nations in 1997.
IMRs decreased from 90.34 to 31.31 per 1000 live births between 1955 and 1995 at an average of 15.3 every 10 years. In contrast, Lorenz curves and Gini coefficients were similar for the five 10 year periods. After grouping by adjusted GNP distribution, a similar decreasing trend of IMR was observed in all groups. The rate ratio between the group at the lowest quintile and that at the highest quintile ranged from 4 to 5. The analysis of variance for repeated observations showed that there is a significant reduction in the IMR (F=130.18; p<0.01), that trends did not differ significantly among groups (F=1.16; p=0.32), and that they were approximately linear (F=155.83; p<0.01).
Despite a sizable reduction in the infant mortality, whether or not income related, levels of IMR inequality among countries have remained almost constant between 1955 and 1995 in the Region of the Americas. Further analysis and focused interventions are needed to tackle the challenges of reducing these persistent mortality inequalities.
描述1955年至1995年美洲地区婴儿死亡率不平等的总体趋势及与收入相关的趋势。
计算婴儿死亡率（IMR），并通过普通最小二乘法评估其趋势。通过比较10年期的IMR、基尼系数和洛伦兹曲线，分析各国间IMR不平等的总体趋势。使用人均国民生产总值（GNP）分布最高和最低五分位数之间的10年期IMR比率（根据购买力调整）评估IMR不平等与收入相关的趋势。
汇总了所有居民超过20万的国家（33个地缘政治单位）的国家数据。1955 - 1995年时间序列中使用的10年期中点IMR估计值是联合国1997年公布的数据。
1955年至1995年期间，每1000例活产婴儿的IMR从90.34降至31.31，平均每10年下降15.3。相比之下，五个10年期的洛伦兹曲线和基尼系数相似。按调整后的GNP分布分组后，所有组中均观察到IMR有类似的下降趋势。最低五分位数组与最高五分位数组之间的率比在4到5之间。重复观察的方差分析表明，IMR有显著下降（F = 130.18；p < 0.01），各组间趋势无显著差异（F = 1.16；p = 0.32），且趋势近似线性（F = 155.83；p < 0.01）。
尽管婴儿死亡率大幅下降，无论是否与收入相关，1955年至1995年期间美洲地区各国间IMR不平等水平几乎保持不变。需要进一步分析和针对性干预措施来应对减少这些持续存在的死亡率不平等的挑战。
