The objective of this study was conducted to examine the reasons for patients' utilization of the emergency department and the rates of readmission in the first 90 days after surgery.

Background: Postoperative readmission rates of patients have been important indicators in the evaluation of quality service delivery and cost-effectiveness. This study was conducted to examine the reasons for patients' utilization of the emergency department and the rates of readmission in the first 90 days after surgery.

Material and methods: The research is based on actual patient data in the hospital information management system. In the study, the data of patients who had undergone surgery between January 1, 2018, and December 31, 2018, and presented to the emergency department in the first 90 days after surgery were retrospectively analyzed. Patient data about the date of surgery, type of surgery, department performing the surgery, patient age, gender, type of anesthesia, the length of postoperative hospital stay, date of discharge, date, and reason for presenting to the emergency department, and discharge status (admission, referral, discharge, or death, etc.) recorded on the hospital information management system were evaluated in accordance with "the 18 HIPAA" standards.

Inclusion Criteria:

• Undergone surgery between January 1, 2018, and December 31, 2018,
• Presented to the emergency department

Exclusion Criteria:

• Patients who do not meet the inclusion criteria

The population of the study consisted of 1705 patients who had undergone surgery between January 1, 2018 and December 31, 2018 and presented to the emergency department within the first 90 days after discharge.