Introduction: Successful colorectal surgery is determined based on postoperative mortality and morbidity rates, complication rates, and cost-effectiveness. One of the methods to obtain an excellent postoperative outcome is the Enhanced Recovery After Surgery (ERAS) protocol. This study aims to see the effects of implementing an ERAS protocol in colorectal surgery patients.

Methods: Eighty-four patients who underwent elective colorectal surgery at National Tertiary-level Hospital were included between January 2021 and July 2022. Patients were then placed into ERAS and control groups according to the criteria. The Patients in the ERAS group underwent a customized 18-component ERAS protocol and were assessed for adherence. Postoperatively, both groups were monitored for up to 30 days and assessed for complications and readmission. The investigators then analyzed the length of stay and total patient costs in both groups.

The investigators aimed to determine whether applying the ERAS protocol to patients undergoing colorectal surgery could improve surgical outcomes (length of stay, complications, readmission, and total costs) in the National Tertiary Hospital clinical setting.

This prospective cohort study to analyze the implementation of ERAS protocol in colorectal patients and its effect on length of stay, readmission rate, complications, and costs in Dr. Cipto Mangunkusumo General Hospital, an Indonesian tertiary-level hospital, from January 2021 to July 2022. ERAS protocol used in this study was arranged based on the guidelines of the ERAS ® Society, with certain adjustments made to fit Indonesia's population characteristics. The sampling process was performed for all patients undergoing elective colorectal surgeries in The Central Surgery Room during the study period, who continued their medical care at Integrated Medical Ward Unit and fulfilled all inclusion and exclusion criteria. In this study, the investigators also used a multidisciplinary team approach that carried out various protocol points in all phases, according to their areas of expertise. This team comprised surgeons, anesthesiologists, physical medicine, internists, rehabilitation specialists, general physicians, dietitians, nurses, pharmacists, surgery admission staff, medical record staff, and hospital administration staff.

Study participants The investigators evaluated patients in two different groups: ERAS and non-ERAS. In both groups, the investigators included patients who underwent elective/non-emergency colorectal surgery above 18 years of age, with a maximum of two different comorbidities to minimize postoperative complications, a body mass index above 18.5 kg/m2, and an ASA below 2. In the ERAS group, patients were first evaluated for eligibility for the ERAS protocol and their willingness to follow a series of ERAS protocols at the outpatient clinic of the Cipto Mangunkusumo Hospital. The Patients registered in the ERAS group followed the protocol of the ERAS research team. For the control group, patients selected through examination in the outpatient clinic would undergo conventional/traditional surgery.

The sample size was calculated using an unpaired numerical, analytical research sample size formula, with an alpha of 5%, a beta of 10%, a combined standard deviation of four based on previous studies, and an assumed mean outcome difference of 3. To obtain a minimum sample size for each group of 37 subjects.

Outcomes The primary outcomes of this study were: (1) the length of hospitalization, (2) postoperative complications, (3) readmission rate, and (4) total medical costs. The length of hospitalization was calculated from the day of admission to the hospital ward until discharge. Postoperative complications were defined as infection on the surgical site or systemic infection, wound dehiscence, and other complications found after surgery. The readmission rate was calculated from discharge to one month after surgery. Total medical costs were calculated based on direct medical costs recorded in the hospital billing data. The currency was converted from Indonesian Rupiah (IDR) to US dollars (USD) based on the September 1, 2022, conversion rate of USD 1 = IDR 14,200.

In addition, the investigators assessed the adherence of patients in the ERAS group to the ERAS protocol. Each implemented protocol component was recorded, and the number of protocols that could be implemented for each patient was calculated. The adherence to the eighteen ERAS protocols was grouped into: <90%, 90-95%, 96-100% for readmission, complications, length of stay <7 days, and costs < USD 3,000 for patients in the ERAS group based on a previous study. The controlled price of USD 3,000 is determined based on hospital's average cost of the non-ERAS group.

Inclusion Criteria:

• maximum of two different comorbidities
• body mass index above 18.5 kg/m2
• ASA below 2

Exclusion Criteria:

• More than 2 comorbidities
• Refused to take part in the research

Colorectal cancer patients undergoing surgery at Dr. Cipto Mangunkusumo General Hospital