Temporal trends, practice patterns, and treatment outcomes for infected upper urinary tract stones in the United States

Abstract

Background: The incidence of infected urolithiasis is unknown, and evidence describing the optimal management strategy for obstruction is equivocal.

Objective: To examine the trends of infected urolithiasis in the United States, the practice patterns of competing treatment modalities, and to compare adverse outcomes.

Design, setting, and participants: A weighted estimate of 396385 adult patients hospitalized with infected urolithiasis was extracted from the Nationwide Inpatient Sample, 1999-2009.

Outcome measurements and statistical analysis: Time trend analysis examined the incidence of infected urolithiasis and associated sepsis, as well as rates of retrograde ureteral catheterization and percutaneous nephrostomy (PCN) for urgent/emergent decompression. Propensity-score matching compared the rates of adverse outcomes between approaches.

Results and limitations: Between 1999 and 2009, the incidence of infected urolithiasis in women increased from 15.5 (95% confidence interval [CI], 15.3-15.6) to 27.6 (27.4-27.8)/100 000); men increased from 7.8 (7.7-7.9) to 12.1 (12.0-12.3)/100000. Rates of associated sepsis increased from 6.9% to 8.5% (p=0.013), and severe sepsis increased from 1.7% to 3.2% (p<0.001); mortality rates remained stable at 0.25-0.20% (p=0.150). Among those undergoing immediate decompression, 113 459 (28.6%), PCN utilization decreased from 16.1% to 11.2% (p=0.001), with significant regional variability. In matched analysis, PCN showed higher rates of sepsis (odds ratio [OR]: 1.63; 95% CI, 1.52-1.74), severe sepsis (OR: 2.28; 95% CI, 2.06-2.52), prolonged length of stay (OR: 3.18; 95% CI, 3.01-3.34), elevated hospital charges (OR: 2.71; 95%CI, 2.57-2.85), and mortality (OR: 3.14; 95%CI, 13-4.63). However, observational data preclude the assessment of timing between outcome and intervention, and disease severity.

Conclusions: Between 1999 and 2009, women were twice as likely to have infected urolithiasis. Rates of associated sepsis and severe sepsis increased, but mortality rates remained stable. Analysis of competing treatment strategies for immediate decompression demonstrates decreasing utilization of PCN, which showed higher rates of adverse outcomes. These findings should be viewed as preliminary and hypothesis generating, demonstrating the pressing need for further study.