BackgroundAcute appendicitis is the most common cause of acute abdomen. During the pandemic, to contain the spread of COVID-19, there were some integral changes in the medical processes based on the pandemic prevention policy, especially regarding emergency surgery. This study was conducted to investigate whether this pandemic also impacted the decision-making for both patients and medical personnel along with the treatment outcomes.MethodsPatients of age 18 years or older who were diagnosed clinically and radiologically with acute appendicitis between Jan 1, 2017, and Dec 31, 202,0 were reviewed. The data of 1991 cases were collected and used for this study. Two groups were formed, one group before and the other group after the outbreak. The gathered data included gender, age, appendiceal fecalith, outcomes of treatment, and long-term outcomes of non-operation (8 months follow-up). We also collected details of surgical cases from the above two groups. This data also included age, gender, appendiceal fecalith, fever, jaundice, length of onset before presenting to an emergency department (ED), anesthesia, surgery, white cell count, pathology, complications, and length of stay. We compared the above data respectively and analyzed the differences.ResultsCompared to the period before the outbreak, patient visits for acute appendicitis remarkably dropped (19.8%), but surgical cases showed no change (dropped by roughly 5%). There were significant differences (P < 0.05) in failure of non-operation(after the pandemic 8.31% vs. before pandemic 3.22%), interval appendectomy(after pandemic 6.29% vs. before pandemic 12.84%), recurrence(after pandemic 23.27% vs. before pandemic 14.46%), and outcomes of recurrence. There was a significant difference (P < 0.05) in anesthesia method, surgery way, and complications( before pandemic 4.15% vs. after pandemic9.89% P < 0.05) in patients who underwent the surgery. There was no statistical difference (P > 0.05) concerning age, gender, fever, jaundice, appendiceal fecalith, white cell count, and length of onset before presenting to the ED.ConclusionThe current pandemic prevention policy is very effective, but some decision-making processes of doctor-patient have changed in the context of COVID-19 pandemic, that further influenced some treatment outcomes and might lead to a potential economic burden. It is essential to address the undue concern of everyone and optimize the treatment process.