Abstract
<title>Abstract</title> <p>Purpose This study used a national mortality database to characterize trends in mortality involving renal and perinephric abscess (RA/PNA) in the United States from 1999 to 2020 and to identify demographic and geographic populations disproportionately affected. Methods We used the CDC WONDER Multiple Cause of Death database to identify deaths listing ICD-10 code N15.1 (renal and perinephric abscess) anywhere on the death certificate between 1999 and 2020. Age-adjusted mortality rates (AAMRs) and crude mortality rates were calculated per 100,000 using the 2000 U.S. standard population. Temporal trends were assessed using segmented log-linear regression, and Poisson regression was used to estimate mortality rate ratios (MRRs) by sex, race, age, and urbanicity. Results A total of 2,375 deaths involving RA/PNA were identified. The overall AAMR declined from 0.0495 to 0.0320 per 100,000 between 1999 and 2020 (average annual percent change, − 1.99%), with a significant decline from 1999–2008 followed by relative stability and a nonsignificant late-period increase from 2017–2020. Mortality was significantly higher in females than males (MRR, 0.71 for males; 95% CI, 0.65–0.77) and increased progressively with age, reaching a substantially higher rate among individuals aged 85 years or older compared with those aged 35–44 years (MRR, 16.00; 95% CI, 12.24–21.24). Residents of small metropolitan, micropolitan, and noncore counties had significantly higher mortality than those in large central metropolitan areas. Conclusions Mortality involving RA/PNA declined modestly from 1999 to 2020, but disparities by age, sex, and urban-rural residence persisted, highlighting populations that may benefit from improved access to timely diagnosis and treatment.</p>