The goal of this retrospective cohort observational study is to learn about the long-term and short-term effects of cholecystectomy in people aged 80 or over the age of 80, who have mild to moderate acute cholecystitis. The main question it aims to answer is:

Does cholecystectomy bring harm or benefit to people aged 80, or over the age of 80, who have mild to moderate acute cholecystitis? People who received cholecystectomy are compared to those who did not, for short- and long-term outcomes, with a follow up period for 18 months.

All data were collected from Shuang-Ho Hospital electronic medical record.

Inclusion Criteria:

• Acute cholecystitis patients aged 80 years or older

Exclusion Criteria:

• Grade III acute cholecystitis
• Concurrent cholangitis, common bile duct stones, pancreatitis, gallbladder cancer, hepatocellular carcinoma, periampullary cancer
• Received other operations at the same admission other than cholecystectomy
• Discharged against advice of physician
• Received further management at another hospital for acute cholecystitis

Patients with mild to moderate (grade I and grade II) acute cholecystitis, who were 80 years old or older, were included.