National trends in hydrocephalus mortality in the United States, 1999-2024: a serial cross-sectional (ecological)...

How did hydrocephalus-attributable mortality trends and disparities evolve in the United States from 1999 to 2024, and what role did the COVID-19 pandemic play in shaping these patterns during and following its onset?

Using national mortality data from the CDC WONDER database (1999-2024), we assessed age-adjusted mortality rates (AAMRs) for hydrocephalus among population aged 0-85+ years. Temporal trends were evaluated via joinpoint regression to calculate annual percent change (APC) and average annual percent change (AAPC) with 95% confidence intervals, stratified by age, gender, ethnicity, census region, and state level.

From 1999 to 2024, a total of 20142 hydrocephalus-related deaths were identified and the overall AAMR for the U.S. population showed a slow but no significant change (AAPC -0.35%, 95% CI: -0.76 to 0.06, P = 0.094), initially decreasing until 2019 before reversing to an increasing trend thereafter. Males had consistently higher mortality than females, with both sexes exhibiting an initial decline followed by a later increase. By age group, the youngest cohort (0-24 years) experienced the steepest decline, while the middle-aged group (25-54 years) showed a modest increase, and the oldest group (≥55 years) displayed a slight decline. Both ethnic groups exhibited a pattern of early decline followed by recent increase, with non-White populations showing steeper changes in both directions. Geographically, both the Northeast and West regions showed an early decline followed by a recent increase, with the Northeast experiencing the largest rise (2014-2024: APC = 5.83, P < 0.001). Oklahoma and West Virginia displayed the steepest percentage increases nationwide (25.4%-62.5%), though these changes did not reach statistical significance. When comparing pre-pandemic (1999-2019) and pandemic (2020-2023) periods, mortality trends reversed from a significant decline (AAPC = -0.87, P = 0.003) to a non-significant increase (AAPC = 3.61, P = 0.12), with notable increases among older adults, non-White populations, and residents of the Northeast and West regions.

In summary, while the overall 26-year trend was stable, this stability masked a consistent reversal pattern across most demographic and geographic subgroups-an early decline followed by a recent increase-most notably among older adults, non-White populations, and residents of the Northeast and West regions. These findings highlight the need for continued surveillance and further investigation into the drivers of this recent shift, while also pointing to the potential value of maintaining equitable access to specialized neurosurgical care for vulnerable populations.