Changes in the epidemiology of under-5 mortality in China from 2016 to 2022: an observational analysis of population-based surveillance data.

Background: Sustainable Development Goal (SDG) 3.2 aims to end preventable deaths of newborns and children younger than 5 years. China's progress towards SDG 3.2 has not been evaluated on multiple dimensions. We aimed to assess mortality rates in children younger than 5 years (hereafter referred to as under-5 mortality) and to quantify preventable child mortality and geospatial and temporal trends in child mortality in China from 2016 to 2022.

Methods: In this observational analysis, we used data from the Chinese National Maternal and Child Health Surveillance System (MCHSS) for the period Jan 1, 2016, to Dec 31, 2022 and conducted all-cause mortality and cause-specific mortality analyses for different age groups (age 0-6 days, 7-27 days, 0-27 days, 1-5 months, 6-11 months, 12-23 months, 24-59 months, and birth to 59 months) separately at the national, residential (rural vs urban), and regional (eastern vs central vs western China) levels. All mortality rates were adjusted by age group, type of residency, region, and region-residency strata using a 3-year moving average of the under-reporting rates. National deaths were estimated using the number of livebirths from 2016 to 2022 from the Health Statistics Yearbook of China. Estimated national-level and regional-level mortality rates were weighted by the proportion of the population living in urban and rural areas from the 2010 national census. Optimal survival metrics for neonates and children younger than 5 years were calculated by cause of death in 2020-22 (termed the national optimum), on the basis of the lowest mortality observed among the six region-residency strata.

Findings: In 2022, approximately 65 700 (95% CI 62 700-68 800) children younger than 5 years died in China, with 45·1% (42·7-47·4) of these deaths occurring in the neonatal period (age <28 days). China's under-5 mortality rate decreased from 10·2 deaths (9·9-10·5) per 1000 livebirths in 2016 to 6·8 deaths (6·5-7·2) per 1000 livebirths in 2022; the neonatal mortality rate decreased from 4·9 deaths (4·7-5·1) per 1000 livebirths in 2016 to 3·1 deaths (2·9-3·3) per 1000 livebirths in 2022. The relative risk of death in children younger than 5 years in rural areas compared with urban areas decreased from 2·4 (2·2-2·6) in 2016 to 1·9 (1·7-2·1) in 2022, and in the western region compared with the eastern region decreased from 3·4 (3·0-3·9) in 2016 to 2·3 (1·9-2·8) in 2022. The leading causes of under-5 mortality in 2022 were injuries (23·1% [21·1-25·1] of all-cause deaths), congenital malformations (14·8% [13·1-16·4]), preterm birth complications (14·1% [12·5-15·7]), intrapartum-related events (10·1% [8·7-11·5]), and acute respiratory infections (9·5% [8·2-10·9]). The leading cause of death in the neonatal period was preterm birth complications (12·8% [11·4-14·2] of deaths in children younger than 5 years).

Interpretation: Under-5 mortality in China declined between 2016 and 2022. Disparities across regions and in urban versus rural areas narrowed over time, but they still exist. Therefore, efforts should be made to further reduce child mortality in China, including consistent investments and implementing of policies, programmes, and interventions, especially for the western rural areas.

Funding: None.

Translation: For the Chinese translation of the abstract see Supplementary Materials section.