title: Charlson comorbidity index and success of extracorporeal shock wave lithotripsy.
abstract: OBJECTIVE
  We examined the potential correlation between Charlson comorbidity index (CCI) and stone free rate after extracorporeal shock wave lithotripsy (ESWL).
  
  
  METHODS
  Two hundred twenty-six adult patients were treated with 241 ESWL procedures for a renal or ureteral stone(s) over a 3 year period. Age, race, comorbidities, CCI, stone size and location, number of shocks and power level were determined. Treatment efficacies were evaluated at a mean of 56.1 days after each ESWL with computed tomography, abdominal x-ray, intravenous pyleography and/or renal ultrasound. Multivariate logistic regression analysis was performed.
  
  
  RESULTS
  There was no correlation between CCI and any of the following: stone burden, number of shocks, or power level. There was no difference in stone burden, number of shocks or power level between those who were and were not stone free. Stone free rates for patients with CCI of zero, one, and two or greater were 44.7% (71/159), 27% (13/48) and 41.2% (14/34) respectively. Patients with an index of one were 2.1 times more likely to have a residual stone burden than patients with an index of zero (95% CI 0.99-4.42, p = 0.05). Patients with one comorbidity were 2.4 times more likely to have a residual stone burden than patients with none (95% CI 1.04-5.72, p = 0.04). Patients with upper ureteral stones were less likely to have a residual stone burden than patients with renal stones (RR = 0.52, 95% CI 0.27-0.98, p = 0.04). Those with lower ureteral stones were less likely to have a residual stone burden than those with renal stones (RR = 0.20, 95% CI 0.09-0.43, p <0.0001). The only significant predictors of the stone free rate were stone location and number of comorbidities.
  
  
  CONCLUSIONS
  Stone location and number of comorbidities were significant predictors of ESWL outcome. The CCI may underestimate the magnitude of comorbidities and their effect on stone treatment efficacy.
authors: Department of Urology, University Hospitals Case Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-5046, USA.
authors: Katherine C
authors: KC
authors: Hubert
authors: Mandeep
authors: M
authors: Singh
authors: Esther H
authors: EH
authors: Zhou
authors: Grace
authors: G
authors: Delos Santos
authors: Mark D
authors: MD
authors: Stovsky
mesh_terms: D000328:Adult; D006305:Health Status Indicators; D006801:Humans; D007669:Kidney Calculi / Q000150:complications / Q000401:mortality / Q000628:therapy*; D008096:Lithotripsy; D012074:Remission Induction; D012189:Retrospective Studies; D014514:Ureteral Calculi / Q000150:complications / Q000401:mortality / Q000628:therapy*