Safety, Efficacy, and Cost-effectiveness of Outpatient Surgery for Uncomplicated Acute Appendicitis: The PENDI-CSI Randomized Clinical Trial.

Objective: To evaluate the safety, efficacy, and cost-effectiveness of outpatient appendectomy in patients with uncomplicated acute appendicitis.

Background: Given that acute appendicitis is the most common cause of acute abdomen, the introduction of outpatient appendectomy protocols could significantly improve the effectiveness and sustainability of health care systems.

Methods: A total of 300 patients were enrolled from October 2018 to June 2021 in the PENDI-CSI randomized clinical trial: 149 were assigned to the outpatient surgery (OPS) group and 151 to the inpatient surgery (IPS) group, followed by 1 month postoperatively. All patients were aged older than 14 years and had uncomplicated acute appendicitis. Exclusion criteria were pregnancy, neoplasms, inflammatory bowel disease, and high anesthetic risk (ASA IV). The OPS group was discharged from the postanesthesia care unit while the IPS group was admitted.

Results: In total, 128 patients in the OPS group (85.9%) were discharged without admission. Predictors whether patients in the OPS group had to be admitted were aged over 31 years [relative risk (RR): 2.42 (1.04-5.65)], hypertension [RR: 6.21 (3.22-11.97)], anesthetic risk II-III [RR: 2.63 (1.17-5.94)], previous abdominal surgery [RR: 3.34 (1.55-7.20)], postoperative pain with visual analog scale >6 [RR: 4.28 (2.67-6.86)], and postoperative fear [RR: 2.2 (1.04-4.67)]. There were no differences in terms of complications, readmissions, and reinterventions, and the perceived quality was similar in both groups. The outpatient modality produced savings of €1 034.97 per patient ( P < 0.001).

Conclusions: Outpatient appendectomy is safe and effective for uncomplicated acute appendicitis. Patient-perceived quality is similar to that of IPS, although it successfully reduces hospital costs compared with inpatient appendectomy.