Sex differences in early and late neonatal all-cause mortality and disease burden in Kazakhstan, 2010-2023: A population-based analysis of Global Burden of Disease estimates.

BACKGROUND

Neonatal mortality remains a major contributor to child mortality globally, with the greatest burden concentrated in the early neonatal period. Sex differences in neonatal survival are consistently reported, yet population-level evidence on sex-specific patterns of all-cause burden across neonatal subperiods in Central Asia remains limited. This study aimed to quantify temporal trends and sex differences in early (0-6 days) and late (7-27 days) neonatal all-cause mortality and disease burden in Kazakhstan from 2010 to 2023, and to examine projected trajectories to 2030.

METHODS

We conducted a population-based time-trend study using Global Burden of Disease 2023 estimates for Kazakhstan. Outcomes included mortality, disability-adjusted life years (DALYs), years of life lost (YLLs), and years lived with disability (YLDs), expressed as age-specific rates per 100,000 person-years within the corresponding neonatal age interval. Analyses were stratified by sex and neonatal subperiod. Temporal patterns were described, and sex differences were assessed using comparative rates. Log-linear models were used to estimate projected trends to 2030. National mortality statistics were used for external trend consistency.

RESULTS

Neonatal mortality and DALY rates declined between 2010 and 2023 in both early and late neonatal periods, with substantially higher rates observed in the early neonatal period. Across all years, males consistently exhibited higher mortality, YLLs, and DALYs than females in both neonatal subperiods; YLD rates followed a different pattern, being modestly higher among females in the early-neonatal period but nearly equal between sexes in the late-neonatal period. YLLs accounted for the vast majority of DALYs, indicating that mortality rather than non-fatal disability drives neonatal burden. Projections suggest continued declines through 2030, male point estimates for mortality and DALYs remained higher than female estimates throughout, although the magnitude of this difference narrowed substantially and became statistically uncertain in the most recent years, with rate-ratio uncertainty intervals spanning or approaching unity.

CONCLUSIONS

Despite substantial reductions in neonatal mortality in Kazakhstan, male point estimates for mortality and burden remained higher than female estimates throughout the study period, although this difference narrowed substantially and became uncertain in recent years; mortality remained heavily concentrated in the early neonatal period. These findings highlight persistent, though narrowing, epidemiologic inequalities within improving population health trends.