BACKGROUND Malnutrition is considered an important contributing factor to child mortality, and the mid-upper arm circumference (MUAC) is regarded as one of the better anthropometric predictors of child mortality. We explored whether the decline in child mortality over recent decades could be explained by changes in children's MUAC. METHODS This prospective study analysed individual-level data from 47 731 children from the capital of Guinea-Bissau followed from 3 months until 36 months of age over 2003 to 2016. We used standardization to compare the mortality rate as if only the MUAC distribution had changed between an early period (2003-05) and a late period (2014-16). We adjusted the analyses for age, sex, socioeconomic-related possessions and maternal education. RESULTS A total of 949 deaths were included in the analysis. The adjusted mortality rate was 18.9 [95% confidence interval (CI) 14.3-23.3] deaths per 1000 person-years (pyrs) in the early period and declined to 4.4 (95% CI 2.9-6.0) deaths per 1000 pyrs in the late period, a 77% (95% CI 71-83%) reduction in the mortality rate. At all calendar years, the MUAC distribution in the population was close to the WHO reference population. MUAC below -1 z-score was associated with increased child mortality. The change in MUAC distribution from the early period to the late period (in the early period mortality standardization) corresponded to 1.5 (95% CI 1.0-2.2) fewer deaths per 1000 pyrs, equivalent to 11% (95% CI 7-14%) of the observed change in child mortality. CONCLUSIONS From 2003 to 2016, child mortality in urban Guinea-Bissau declined considerably but, though a low MUAC was associated with increased mortality, changes in the MUAC distribution in the population explained little of the decline. Understanding the driving factors of child mortality decline can help scope tomorrow's interventions.

中文翻译：

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了解几内亚比绍儿童死亡率的下降：通过中上臂围测量的人口营养状况的作用。

背景 营养不良被认为是导致儿童死亡率的一个重要因素，而中上臂围 (MUAC) 被认为是儿童死亡率更好的人体测量预测指标之一。我们探讨了近几十年来儿童死亡率的下降是否可以用儿童 MUAC 的变化来解释。方法 这项前瞻性研究分析了 2003 年至 2016 年间来自几内亚比绍首都的 47 731 名儿童的个体水平数据，从 3 个月到 36 个月大。我们使用标准化来比较死亡率，就好像只有 MUAC 分布发生了变化在早期（2003-05）和晚期（2014-16）之间。我们调整了年龄、性别、社会经济相关财产和母亲教育的分析。结果 共有 949 例死亡被纳入分析。调整后的死亡率在早期为每千人年 (pyrs) 18.9 [95% CI 14.3-23.3] 死亡人数，后期下降至每千人每年 4.4 (95% CI 2.9-6.0) 死亡人数期间，死亡率降低 77% (95% CI 71-83%)。在所有日历年中，MUAC 在人群中的分布都接近于 WHO 参考人群。MUAC 低于 -1 z 分数与儿童死亡率增加有关。MUAC 分布从早期到晚期的变化（在早期死亡率标准化中）对应于每 1000 pyrs 死亡人数减少 1.5 (95% CI 1.0-2.2)，相当于 11% (95% CI 7-14% ) 观察到的儿童死亡率变化。结论 从 2003 年到 2016 年，几内亚比绍城市的儿童死亡率大幅下降，但是，尽管低 MUAC 与死亡率增加有关，但人口中 MUAC 分布的变化几乎不能解释死亡率的下降。了解儿童死亡率下降的驱动因素有助于确定未来的干预措施。