Age distribution, trends, and forecasts of under-5 mortality in 31 sub-Saharan African countries: A modeling study
Age distribution, trends, and forecasts of under-5 mortality in 31 sub-Saharan African countries: A modeling study
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DOI：
10.1371/journal.pmed.1002757
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发表时间：
2019-03-01
期刊：
影响因子：
15.8
通讯作者：
Tuljapurkar, Shripad
中科院分区：
文献类型：
--
作者：
Mejia-Guevara, Ivan;Zuo, Wenyun;Tuljapurkar, Shripad
背景 尽管自 1990 年以来全球 5 岁以下儿童死亡率急剧下降，但各国之间和各国内部取得的进展并不均衡。在撒哈拉以南非洲（SSA），只有少数国家实现了关于儿童死亡率的千年发展目标（MDG）。该地区是否能够实现针对 5 岁以下儿童死亡率的新可持续发展目标 (SDG) 存在合理的担忧。因此，我们通过评估年龄模式、趋势和死亡率预测来进一步研究变异来源。方法和结果数据来自 106 项具有全国代表性的人口和健康调查 (DHS)，其中包含 31 个 SSA 国家 1990 年至 2017 年的完整出生史（总共 524 个国家/地区的数据）。我们通过以下新的人口统计分析评估了死亡年龄的分布。首先，我们使用直接方法和完整的出生史每月估算 5 岁以下死亡率 (U5MR)。其次，我们使用二维 P 样条方法平滑了按年龄和时间划分的死亡率的原始估计。第三，Lee-Carter (LC) 模型的一个变体是为数据有限的人群设计的，用于拟合和预测死亡率的年龄特征。我们使用联合国儿童死亡率估计机构间小组 (UN IGME) 的死亡率估计值来调整、验证和最小化死亡率估计中生存、截断和回忆方面的偏差风险。我们的死亡率模型显示，大多数国家每个年龄段的死亡率均大幅下降，但随着时间的推移，年龄模式存在显着差异。 U5MR 从莱索托的 3.3%（年减少率 [ARR] 0.1%）下降到马拉维的 76.4%（ARR 5.2%），平均下降速度（ARR 3.2%）比观察到的婴儿（IMR）（ARR 2.7%）和新生儿（NMR）（ARR 2.0%）死亡率要快。我们预测，5 个国家（肯尼亚、卢旺达、塞内加尔、坦桑尼亚和乌干达）有望在 2030 年实现 5 岁以下儿童可持续发展目标（每 1,000 名活产儿 25 人死亡），但只有卢旺达和坦桑尼亚能够同时实现新生儿（每 1,000 名活产儿 12 人死亡）和 5 岁以下儿童目标。我们预测的 NMR 和 U5MR 与联合国 IGME 到 2030 年和 2050 年的估计值一致（27/31 个国家的 NMR 值重叠，22 个国家的 U5MR 值重叠），以及健康指标与评估研究所 (IHME) 到 2030 年的估计值（分别为 26/31 和 23/31）。这项研究有许多局限性，包括数据质量差，反映了出生和死亡报告中的偏差，妨碍了少数国家的可靠估计和预测。 结论 据我们所知，这项研究是第一个将完整的出生史和来自外部可靠来源的死亡率估计结合起来的研究，以模拟 SSA 不同时期 5 岁以下死亡率的年龄模式。我们证明，各个年龄段死亡率下降速度较快（ARR 3.2%）的国家更有可能实现可持续发展目标死亡率目标。然而，新生儿死亡率降低速度较慢将阻碍大多数国家实现这些目标：2 个国家将在 2030 年实现这些目标，13 个国家将在 2030 年至 2050 年期间实现，13 个国家将在 2050 年之后实现。
Background Despite the sharp decline in global under-5 deaths since 1990, uneven progress has been achieved across and within countries. In sub-Saharan Africa (SSA), the Millennium Development Goals (MDGs) for child mortality were met only by a few countries. Valid concerns exist as to whether the region would meet new Sustainable Development Goals (SDGs) for under-5 mortality. We therefore examine further sources of variation by assessing age patterns, trends, and forecasts of mortality rates.Methods and findings Data came from 106 nationally representative Demographic and Health Surveys (DHSs) with full birth histories from 31 SSA countries from 1990 to 2017 (a total of 524 country-years of data). We assessed the distribution of age at death through the following new demographic analyses. First, we used a direct method and full birth histories to estimate under-5 mortality rates (U5MRs) on a monthly basis. Second, we smoothed raw estimates of death rates by age and time by using a two-dimensional P-Spline approach. Third, a variant of the Lee-Carter (LC) model, designed for populations with limited data, was used to fit and forecast age profiles of mortality. We used mortality estimates from the United Nations Inter-agency Group for Child Mortality Estimation (UN IGME) to adjust, validate, and minimize the risk of bias in survival, truncation, and recall in mortality estimation. Our mortality model revealed substantive declines of death rates at every age in most countries but with notable differences in the age patterns over time. U5MRs declined from 3.3% (annual rate of reduction [ARR] 0.1%) in Lesotho to 76.4% (ARR 5.2%) in Malawi, and the pace of decline was faster on average (ARR 3.2%) than that observed for infant (IMRs) (ARR 2.7%) and neonatal (NMRs) (ARR 2.0%) mortality rates. We predict that 5 countries (Kenya, Rwanda, Senegal, Tanzania, and Uganda) are on track to achieve the under-5 sustainable development target by 2030 (25 deaths per 1,000 live births), but only Rwanda and Tanzania would meet both the neonatal (12 deaths per 1,000 live births) and under-5 targets simultaneously. Our predicted NMRs and U5MRs were in line with those estimated by the UN IGME by 2030 and 2050 (they overlapped in 27/31 countries for NMRs and 22 for U5MRs) and by the Institute for Health Metrics and Evaluation (IHME) by 2030 (26/31 and 23/31, respectively). This study has a number of limitations, including poor data quality issues that reflected bias in the report of births and deaths, preventing reliable estimates and predictions from a few countries.Conclusions To our knowledge, this study is the first to combine full birth histories and mortality estimates from external reliable sources to model age patterns of under-5 mortality across time in SSA. We demonstrate that countries with a rapid pace of mortality reduction (ARR 3.2%) across ages would be more likely to achieve the SDG mortality targets. However, the lower pace of neonatal mortality reduction would prevent most countries from achieving those targets: 2 countries would reach them by 2030, 13 between 2030 and 2050, and 13 after 2050.