PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

**Background:** Acute pancreatitis is a common emergency surgical presentation in the UK, with an incidence of 56 per 100,000 per year. Despite multiple guidelines, management varies significantly. This national, multicentre, prospective cohort study aimed to assess current population characteristics, trends in presentation and care, and patient outcomes across the UK.

**Methods:** All patients aged ≥18 years presenting with acute pancreatitis (per revised Atlanta criteria: two of three criteria — abdominal pain, serum amylase/lipase >3× upper limit of normal, or characteristic imaging findings) from March to April 2021 were eligible. Patients transferred from another hospital after initial presentation were excluded. Anonymized data were entered into REDCap. Sites with <95% data completion or failing to submit patients throughout the study interval were excluded (two centres excluded). Severity was classified as mild (no organ failure or complications), moderately severe (transient organ failure <48 h and/or local/systemic complications), or severe (persistent organ failure >48 h). Outcomes included critical care admission, referral to tertiary specialty, nutritional support, length of stay, aetiology, and 30-day mortality. Multilevel logistic regression models accounted for case mix with hospital as random intercepts.

**Key Results:** 113 hospitals contributed data on 2580 patients (50.1% male; median age 57 years, IQR 41–72). Aetiology: gallstones 50.6%, idiopathic 22.4%, alcohol 19.3%, other causes 7.7%. 7.6% had known chronic pancreatitis; 20.1% had a previous acute pancreatitis episode. Severity: mild 71.2%, moderately severe 23.1%, severe 5.7%. Overall 30-day mortality was 2.3% (73/2580), rising to 34.5% in the severe group. Median length of stay: 4 days (mild), 8 days (moderate), 17 days (severe). ICU admission: 0.5% mild, 8.7% moderate, 60.1% severe. Antibiotics were prescribed within 48 h in 34% of patients (9.6% prophylactically, 20.3% for suspected infection, 4.7% for proven infection). Ultrasound was performed in 60.0% of patients; CT in 53.3% (median 1 day from admission). MRCP was performed in 40.9%. Endoscopic ultrasound was performed in only 1.2%. Of 1272 patients eligible for cholecystectomy, only 34.7% had one within 30 days; 21.6% had no decision made by discharge. Multivariable modelling showed predictors of death included male sex, older age, frailty, and alcohol or post-ERCP aetiology. Previous acute pancreatitis and gallstone aetiology were protective. BMI and smoking did not affect mortality.

**Clinical Implications:** Most acute pancreatitis is mild and can be managed in non-specialist centres (<1% required tertiary transfer). The high rate of idiopathic pancreatitis (22.4%) indicates underuse of advanced imaging (EUS, MRCP) to identify aetiology. Antibiotic overuse (34% within 48 h) contradicts guidelines recommending against prophylactic use. The low rate of cholecystectomy within 30 days (34.7%) and high rate of no decision (21.6%) suggest delays in definitive management of gallstone pancreatitis. The protective effect of prior pancreatitis on severity may inform clinical decision-making and patient counselling. Limitations include short (30-day) follow-up and data collection during the COVID-19 pandemic, which may have affected practice.