Mortality involving neuromuscular dysfunction of the bladder in the United States, 1999–2024: a serial cross-sectional analysis of national death certificate data
Mortality involving neuromuscular dysfunction of the bladder in the United States, 1999–2024: a serial cross-sectional analysis of national death certificate data
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Original abstract
Abstract Background. Neuromuscular dysfunction of the bladder, commonly termed neurogenic bladder, is a shared endpoint of spinal cord injury, spina bifida, multiple sclerosis, Parkinson’s disease, stroke, and diabetes. Its complications, including recurrent urinary tract infection, upper urinary tract deterioration, and renal failure, are well described, but no national analysis of mortality has been reported. We examined trends in deaths involving neurogenic bladder in the United States over 26 years. Methods. We conducted a serial cross-sectional analysis of the CDC WONDER Multiple Cause of Death files for 1999–2024, including decedents aged ≥ 25 years for whom International Classification of Diseases, Tenth Revision codes N31.0–N31.9 appeared anywhere on the death certificate. Deaths from 1999 to 2020 were drawn from the standard file and deaths from 2021 to 2024 from the expanded file, with overlapping years cross-checked. Age-adjusted mortality rates (AAMR) per 100,000 were calculated using direct standardization to the 2000 US standard population. Trends were estimated using joinpoint regression, yielding annual percent change (APC) per segment and average annual percent change (AAPC) per stratum. A prespecified sensitivity analysis used a narrower definition restricted to deaths for which neurogenic bladder was recorded as the underlying cause. Results. Of the 23,982 deaths involving neurogenic bladder, 18,847 (78.6%) occurred among adults aged ≥ 65 years, and 14,169 (59.1%) occurred among men. The AAMR fell from 0.42 per 100,000 in 1999 to an inflection in 2008 (95% CI 2005–2014), declining 3.00% per year (95% CI − 5.32 to − 0.62), and then rose 3.81% per year (95% CI 3.06 to 4.56) to 0.55 per 100,000 in 2024. Rates declined and then increased in all 14 strata examined, although the initial decline was statistically significant in 10. The steepest relative increase in mortality rates occurred in younger adults, although adults aged > 65 years accounted for the most deaths and the largest absolute number of deaths. Among the adults aged 25–44 years, mortality rates rose 12.58% per year after 2014 (95% CI 9.41 to 15.85) and among those aged 45–64 years 5.69% per year after 2007, whereas the rate among adults aged 65 and older did not change materially over the full period (AAPC 0.18%, 95% CI − 0.49 to 0.86). Rates rose 7.42% per year after 2013 among non-Hispanic Black decedents (95% CI 5.08–9.81) and 4.02% per year after 2008 among non-Hispanic White decedents. In the sensitivity analysis, the trend moved in the opposite direction: deaths with neurogenic bladder as the underlying cause declined by 3.69% per year from 1999 to 2018 (95% CI − 4.88 to − 2.49), with no significant change thereafter, and their share of all deaths involving the condition halved, from 20.3% in 1999 to 9.7% in 2024. Expressed as a proportion of all deaths among adults aged ≥ 25 years, deaths involving neurogenic bladder increased by 48%, from 3.40 to 5.03 per 10,000 deaths. Conclusions. Deaths involving neurogenic bladder have increased since 2008, whereas deaths attributed to it have decreased. The national burden of neurogenic bladder is increasingly recorded as a comorbidity at death rather than as a cause of death. The increase is specific to this condition rather than a by-product of more complete death certification, as it is present as a proportion of all deaths. Improved urological care and changes in the recognition or recording of the neurogenic bladder cannot be distinguished using these data. The concentration of the rate increase in adults aged 25–44 years is consistent with a growing population surviving congenital and acquired neurogenic bladder into adulthood and highlights a group for whom transitional urological care may be particularly important.