Admission Volume Determines Outcome for Patients With Acute Pancreatitis

Background & Aims

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, ≥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.

Abbreviations used in this paper: CI, confidence interval, HV, high volume, ICD-9-CM, Clinical Modification of the International Classification of Diseases, 9th Revision, LV, low volume, NIS, Nationwide Inpatient Sample, OR, odds ratio