title: Admission volume determines outcome for patients with acute pancreatitis.
abstract: OBJECTIVE
  There is controversy over the optimal management strategy for patients with acute pancreatitis (AP). Studies have shown a hospital volume benefit for in-hospital mortality after surgery, and we examined whether a similar mortality benefit exists for patients admitted with AP.
  
  
  METHODS
  Using the Nationwide Inpatient Sample, discharge records for all adult admissions with a primary diagnosis of AP (n = 416,489) from 1998 to 2006 were examined. Hospitals were categorized based on number of patients with AP; the highest third were defined as high volume (HV, >or=118 cases/year) and the lower two thirds as low volume (LV, <118 cases/year). A matched cohort based on propensity scores (n = 43,108 in each group) eliminated all demographic differences to create a case-controlled analysis. Adjusted mortality was the primary outcome measure.
  
  
  RESULTS
  In-hospital mortality for patients with AP was 1.6%. Hospital admissions for AP increased over the study period (P < .0001). HV hospitals tended to be large (82%), urban (99%), academic centers (59%) that cared for patients with greater comorbidities (P < .001). Adjusted length of stay was lower at HV compared with LV hospitals (odds ratio, 0.86; 95% confidence interval, 0.82-0.90). After adjusting for patient and hospital factors, the mortality rate was significantly lower for patients treated at HV hospitals (hazard ratio, 0.74; 95% confidence interval, 0.67-0.83).
  
  
  CONCLUSIONS
  The rates of admissions for AP in the United States are increasing. At hospitals that admit the most patients with AP, patients had a shorter length of stay, lower hospital charges, and lower mortality rates than controls in this matched analysis.
authors.affiliation: Department of Surgery, Surgical Outcomes Analysis & Research, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
authors.forename: Anand
authors.initials: A
authors.lastname: Singla
authors.forename: Jessica
authors.initials: J
authors.lastname: Simons
authors.forename: YouFu
authors.initials: Y
authors.lastname: Li
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Csikesz
authors.forename: Sing Chau
authors.initials: SC
authors.lastname: Ng
authors.forename: Jennifer F
authors.initials: JF
authors.lastname: Tseng
authors.forename: Shimul A
authors.initials: SA
authors.lastname: Shah
mesh_terms: D000208:Acute Disease; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D006302:Health Services Research; D017721:Hospital Costs; D017052:Hospital Mortality; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data*; D010195:Pancreatitis / Q000175:diagnosis / Q000191:economics / Q000401:mortality / Q000628:therapy*; D010343:Patient Admission / Q000191:economics / Q000706:statistics & numerical data*; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology