title: Emergency department revisits for patients with kidney stones in California.
abstract: OBJECTIVE
  Kidney stones affect nearly one in 11 persons in the United States, and among those experiencing symptoms, emergency care is common. In this population, little is known about the incidence of and factors associated with repeat emergency department (ED) visits. The objective was to identify associations between potentially mutable factors and the risk of an ED revisit for patients with kidney stones in a large, all-payer cohort.
  
  
  METHODS
  This was a retrospective cohort study of all patients in California initially treated and released from EDs for kidney stones between February 2008 and November 2009. A multivariable regression model was created to identify associations between patient-level characteristics, area health care resources, processes of care, and the risk of repeat ED visits. The primary outcome was a second ED visit within 30 days of the initial discharge from emergent care.
  
  
  RESULTS
  Among 128,564 patients discharged from emergent care, 13,684 (11%) had at least one additional emergent visit for treatment of their kidney stone. In these patients, nearly one in three required hospitalization or an urgent temporizing procedure at the second visit. On multivariable analysis, the risk of an ED revisit was associated with insurance status (e.g., Medicaid vs. private insurance; odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.43 to 1.61; p < 0.001). Greater access to urologic care was associated with lower odds of an ED revisit (highest quartile OR = 0.88, 95% CI = 0.80 to 0.97; p < 0.01 vs. lowest quartile). In exploratory models, performance of a complete blood count was associated with a decreased odds of revisit (OR = 0.86, 95% CI = 0.75 to 0.97; p = 0.02).
  
  
  CONCLUSIONS
  Repeat high-acuity care affects one in nine patients discharged from initial emergent evaluations for kidney stones. Access to urologic care and processes of care are associated with lower risk of repeat emergent encounters. Efforts are indicated to identify preventable causes of ED revisits for kidney stone patients and design interventions to reduce the risk of high-cost, high-acuity, repeat care.
authors.affiliation: Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC; Division of Urologic Surgery, Duke University School of Medicine, Durham, NC; Robert Wood Johnson Foundation/VA Clinical Scholars Program, University of California at Los Angeles, Los Angeles, CA.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Scales
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Saigal
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Bennett
authors.forename: Ninez A
authors.initials: NA
authors.lastname: Ponce
authors.forename: Carol M
authors.initials: CM
authors.lastname: Mangione
authors.forename: Mark S
authors.initials: MS
authors.lastname: Litwin
mesh_terms: D000293:Adolescent; D000328:Adult; D002140:California; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D019458:Insurance Coverage / Q000706:statistics & numerical data; D007669:Kidney Calculi / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010351:Patient Discharge / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States; D055815:Young Adult