WASHINGTON – Performed when recommended, cholecystecomy significantly decreases the risk of near-term rehospitalization for acute biliary pancreatitis, results of a retrospective study indicate.
Among more than 23,000 patients with mild to moderate acute biliary pancreatitis, less than 2% of those who underwent cholecystectomy within 30 days, as recommended under American Gastroenterological Association (AGA) guidelines, were rehospitalized for pancreatitis within 6 months.
In contrast, nearly 17% of patients who had cholecystectomy after 1 month or never had it were back in the hospital within half a year, said Dr. Ayesha Kamal, a postdoctoral research fellow at the Johns Hopkins Hospital in Baltimore.
“Cholecystectomy prevents future hospitalization for biliary pancreatitis,” she said at the annual Digestive Disease Week.
The study, based on claims data, also showed that adherence to AGA guidelines is fairly high, on the order of 75%, she said.
Acute pancreatitis is one of the most common gastrointestinal diseases in the United States, accounting for about 300,000 hospitalizations in 2009, at a total cost of about $2.6 billion.
Gallstone disease is the most common cause of acute pancreatitis, responsible for an estimated 40% of all cases, she said.
Guidelines from the AGA and other organizations recommend cholecystectomy either during the same hospitalization for acute biliary pancreatitis, or within 4 weeks.
To see whether clinicians were adhering to the AGA guidelines and whether the guideline-recommended timing of cholecystectomy made a difference, Dr. Kamal and colleagues analyzed data from the MarketScan Commercial Claims & Encounters database, which includes individual-level clinical utilization data for both inpatient and outpatient visits paid for by employer-sponsored health plans.
They looked at data both on patients who were treated in accordance with guidelines (first hospitalization for mild to moderate acute biliary pancreatitis, with cholecystectomy performed either on the day of hospitalization or within 30 days), and outside of the guidelines (no cholecystectomy, or cholecystectomy performed later than 30 days after the index hospitalization).
They assessed recurrences within 30 days of follow-up by International Classification of Diseases, 9th Revision (ICD-9) codes for acute pancreatitis and gallstone disease.
Combing through 8.8 million adult inpatient encounters for acute biliary pancreatitis, they excluded those patients with a diagnosis of severe or chronic pancreatitis, alcohol abuse, less than 30 days of follow-up, deaths during hospitalization, discharge to hospice, and those with a length of stay longer than 30 days.
This left them with a final cohort of 23,515 patients with mild to moderate acute biliary pancreatitis.
They found that 61% of patients had cholecystectomy during their initial hospitalizations, and an additional 14% had the surgery during a subsequent hospitalization within 30 days. Of the remaining patients, 7% had cholecystectomies after 30 days, and 18% never had one.
Among patients treated under the guidelines, 1.3% who had their gallbladders removed during the initial hospitalization had a pancreatitis recurrence within 6 months, and 0.2% had a recurrence more than 6 months later.
In contrast, 36.7% of patients who had a cholecystectomy more than a month after their first hospitalization for pancreatitis had a recurrence within 6 months, and 4.5% had a recurrence after 6 months.
Among patients who never underwent cholecystectomy, the respective recurrence rates were 5.4% and 1.1%.
“One in six patients who did not receive a cholecystectomy within 30 days will be hospitalized again within 6 months,” Dr. Kamal said.
She acknowledged that the study was limited by the authors’ inability to confirm acute biliary pancreatitis with chart review, and by the limitations of the database, which is confined to adults younger than 65 with employer-sponsored medical plans.
In the question and answer portion of the presentation, Dr. Nirav Thosani, a gastroenterologist at Memorial Hermann Hospital in Houston, noted that ICD-9 codes do not distinguish between different types of pancreatitis.
“It might be possible that those patients who never had cholecystectomy never had acute biliary pancreatitis, or some other reason for acute pancreatitis, and that’s the reason for the rehospitalization,” he said.
Dr. Kamal replied that they tried to control for other causes of pancreatitis by including ICD-9 codes for gallstone disease and by excluding patients with diagnoses of alcohol abuse.
