Infant mortality in the Brazilian countryside: a proposal to overcome epidemiological and demographic invisibility

Abstract: The study aimed to compare two concepts of rurality, one proposed by the Brazilian Institute of Geography and Statistics (IBGE) and the other by the World Bank, to determine which is better fitted to the territory’s reality, besides analyzing the infant mortality profile of rural municipalities (counties) in the state of Paraíba, Brazil, according to the best criterion for rurality. This was an observational epidemiological study conducted in the state of Paraíba. The method for analyzing rural/urban typologies was based on data mining, using the Apriori algorithm of association. Infant mortality was analyzed with descriptive statistics. The data were obtained from the Mortality Information System of the Brazilian Ministry of Health, from 2007 to 2016, and municipal indicators were from IBGE. The World Bank definition of rurality showed kappa = 0.337, compared to the IBGE definition, with kappa = 0.616. Among the 223 municipalities that were analyzed, the World Bank classified 130 (65.66%) correctly, and the IBGE 183 (82.06%). The predominant epidemiological profile of infant mortality in rural municipalities in Paraiba state was male gender (57.4%), brown skin color (61.1%), age from 0 to 7 days (52.4%), low birthweight (44%), and gestational age less than 37 weeks (43.2%). Underlying cause of death was classified as avoidable death via interventions by the Brazilian Unified National Health System (65.2%). The urban/rural typology adopted by the IBGE was better than the World Bank at classifying the municipalities in Paraiba state. This classification allowed studying the infant mortality profile in rural municipalities, which was similar to the overall profile, except for maternal schooling.

摘要：本研究旨在对比两种乡村性界定概念——分别由巴西地理与统计研究所（Brazilian Institute of Geography and Statistics, IBGE）和世界银行（World Bank）提出——以甄别更贴合该地域实际情况的判定标准；同时依据最优乡村性准则，分析巴西帕拉伊巴州乡村市镇（县域）的婴儿死亡率特征。本研究为在帕拉伊巴州开展的观察性流行病学研究。乡村/城市分型的分析方法基于数据挖掘（data mining），采用关联规则Apriori算法（Apriori algorithm）。婴儿死亡率分析采用描述性统计方法。研究数据来源于2007至2016年巴西卫生部死亡信息系统（Mortality Information System），市镇相关指标取自IBGE。与IBGE界定标准的科恩Kappa系数（Cohen's Kappa coefficient）0.616相比，世界银行的乡村性界定标准的科恩Kappa系数为0.337。在所分析的223个市镇中，世界银行分类正确的有130个（占比65.66%），IBGE分类正确的有183个（占比82.06%）。帕拉伊巴州乡村市镇的婴儿死亡率主要流行病学特征为：男性占比57.4%，棕肤色占比61.1%，死亡年龄集中于0~7日龄（占比52.4%），低出生体重占比44%，孕周不足37周占比43.2%。可通过巴西统一国家卫生系统（Brazilian Unified National Health System）干预避免的死亡为主要潜在死亡原因，占比65.2%。IBGE采用的城乡分型标准在帕拉伊巴州市镇分类中优于世界银行标准。该分类体系可为乡村市镇婴儿死亡率特征研究提供支撑，其特征与整体婴儿死亡率特征基本一致，仅母亲受教育水平这一指标存在差异。