Ghani KR et al, 2013: Trends in surgery for upper urinary tract calculi in the USA using the Nationwide Inpatient Sample: 1999-2009
Ghani KR, Sammon JD, Karakiewicz PI, Sun M, Bhojani N, Sukumar S, Peabody JO, Menon M, Trinh QD
Vattikuti Urology Institute, Henry Ford Health System, Detroit, MI 48202, USA
OBJECTIVE: 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.
RESULTS: 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.
CONCLUSIONS: 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.
BJU Int. 2013 Mar 11. doi: 10.1111/bju.12059. [Epub ahead of print]
PMID:23480795 [PubMed - as supplied by publisher]. FREE ARTICLE
The title is misleading. It should actually read "Trends in inpatient surgery..." Unfortunately the data offer only a view on trends in inpatient surgery but not on general trends in active stone treatment or the epidemiology of urolithiasis.
The authors discuss some important limitations of their study: "one reason why women may have had a greater increase in admissions than men is that women might be more likely than men to present with UTI, and therefore be hospitalized. Second, the NIS is a snapshot of a patient's admission and the study does not distinguish patients who may have had multiple admissions for the same calculus episode or intervention. ...
Fourth, the accuracy of coding for procedures is unclear. Although ICD-9 coding for identifying patients with upper urinary tract calculi has been shown to have good validity, it may not be a reliable way of differentiating between patients with ureteric and renal calculi. Fifth, the nature of the dataset does not allow the capturing of risk factors for urolithiasis and we can only hypothesize on causality, such as rising obesity in women. Finally, as already discussed, patients discharged from the emergency room or those undergoing outpatient procedures are not captured."