• kidney calculi;
  • urolithiasis;
  • ureteric calculi;
  • trends;
  • treatment


  • To determine trends in demographics and treatment for inpatient upper urinary tract calculi in the USA using a population-based cohort.

Patients and Methods

  • All patients with a primary or secondary diagnosis of kidney or ureteric calculus between 1999 and 2009 in the US Nationwide Inpatient Sample were extracted and weighted.
  • Temporal trend analyses were used to determine trends in gender, race and age presentation, as well as utilization rates of interventions.
  • Temporal trends were quantified using the estimated annual percent change (EAPC) using least squares linear regression analysis.


  • Overall, 2 109 455 patients were hospitalized with upper urinary tract calculi over the 11-year period. The majority of admissions were for ureteric calculi (63.4%).
  • Admissions for renal calculus increased by 12.1% during the study period (EAPC + 0.92%, P = 0.039, 95% CI: 0.17–1.66), whilst discharges for ureteric calculus remained stable.
  • A significant increase (25.4%) in hospitalizations for women was found (EAPC + 2.21%, P < 0.001, 95% CI: 1.40–3.03); by 2006, more women than men were admitted to hospital (95 953 vs. 94 556, respectively).
  • There were significant increases in hospitalization for black, Hispanic and older patients.
  • Significant changes in the use of all studied interventions were found except for ureteroscopy, extracorporeal shockwave lithotripsy and nephrectomy.


  • In this nationally representative sample of inpatient discharges, significant increases were found in admissions for renal compared with ureteric calculi, and for black, Hispanic and older patients.
  • With regard to surgical intervention, the largest increase was found in the use of procedures for kidney calculi.
  • Women now comprise the majority in the inpatient management of stone disease.