Social inequality and pneumonia hospitalization in children under five years of age in Maranhão, Brazil

Abstract Objectives: to describe the characteristics of pneumonia hospitalizations in children under five years of age across the State of Maranhão, Brazil, and explore patterns of spatial distribution of admissions. Methods: ecological study using data on occurrences (age, gender, skin color/race, month of occurrence, and municipality of residence) between 2012 and 2017 taken from the Unified Health System’s Hospital Information System and municipal level socioeconomic indicators for 2010. Each respiratory disease, including pneumonia, was presented as a percentage of overall admissions for respiratory tract diseases, together with the monthly distribution of admissions as a percentage of total annual cases, and annual rate of admissions by gender. The General G* statistic was calculated to identify significant clustering of municipalities with similar proportions of hospital admissions for pneumonia relative to overall hospital admissions. Results: pneumonia was the leading cause of admissions for respiratory disease, accounting for 57% of all cases and occurring with greater frequency in the rainy season (February to June) and in cities with lower socioeconomic indicator values. The rate of admissions decreased over the study period. Significant clusters (p<0.05) of municipalities with high proportions of hospital admissions for pneumonia relative to overall hospital admissions occurred predominantly in the south of the state, while clusters with low propor-tions were located mainly in and around the metropolitan region of the state capital São Luís. Conclusions: pneumonia was shown to be a key cause of hospitalization in children and its distribution was associated with contextual socioeconomic factors, reflecting the quality of life and health status of children in Maranhão.

摘要
研究目的：旨在描述巴西马拉尼昂州（Maranhão）5岁以下儿童肺炎住院病例的特征，并探究住院病例的空间分布模式。
研究方法：本研究为生态学研究，采用巴西统一卫生系统（Unified Health System）医院信息系统中2012至2017年的病例数据（包括患者年龄、性别、肤色/种族、发病月份及居住市镇），以及2010年市级层面的社会经济指标。将包括肺炎在内的各类呼吸系统疾病占呼吸系统疾病总住院病例的比例、住院病例的月度分布（以年度总病例数的百分比计）以及按性别划分的年住院率分别进行呈现；通过计算广义G*统计量（General G* statistic），识别出肺炎住院病例占总住院病例比例相似的市镇的显著聚集区域。
研究结果：肺炎为呼吸系统疾病住院病例的首要病因，占全部病例的57%，且在雨季（2月至6月）以及社会经济指标较低的市镇中发病更为频繁。研究期间，年住院率呈下降趋势。肺炎住院病例占总住院病例比例较高的显著聚集区域（p<0.05）主要分布于该州南部；而比例较低的聚集区域则主要位于州首府圣路易斯（São Luís）都会区及其周边区域。
研究结论：肺炎是儿童住院的关键病因，其空间分布与当地社会经济背景因素相关，反映了马拉尼昂州儿童的生活质量与健康状况。