This study includes participants undergoing major hepatic surgery, surgery in the esophagus or stomach, or major surgery on the pancreas performed at Copenhagen University Hospital, Rigshospitalet. The aims of the study 1: To record patients' level of catastrophizing preoperatively and pain perioperatively, and pain treatment, as well as related side effects. Furthermore, to investigate whether it is possible to assign the task of rating pain scores to the patient.

2. To investigate patients' expectations preoperatively and the fulfillment of these expectations 30 days after, and the development of chronic pain after 6 months. 3. To record patients' pre- and postoperatively rated health and daily quality of recovery during the seven days of admission. Furthermore, patients' symptoms, levels of pain, and use of analgesics will be assessed 30 days and six months after discharge.

This study includes one main study and two sub-studies. The main study and sub-study 1a are both prospective observational cohort studies. Study 1b is a qualitative study that includes semi-structured interviews with the included patients. No formal sample size calculation was performed, as the study method is exploratory.

Location of the study This study will be conducted at the Department of Transplantation and Organ Surgery at Copenhagen University Hospital, Rigshospitalet, Denmark, from October 1, 2025, to October 1, 2026. Study 1b will be performed by phone.

Participants The participants will include patients undergoing major hepatic surgery, surgery in the esophagus or cardia, or major surgery on the pancreas performed at Rigshospitalet.

Inclusion criteria Patients must meet the following criteria to be suitable for inclusion in the study.

Patients > 18 years undergoing elective primary surgical treatment according to the protocol with curative intent. Patients who can read and understand the Danish language.

Exclusion criteria Patients meeting one or more of the following criteria are ineligible for inclusion in this study.

Patients who are cognitively disabled and cannot mentally cooperate with the study design, as assessed by the investigator.

Procedure for patients who withdraw from the trial In accordance with the Declaration of Helsinki 24, patients have the right to withdraw from the study at any time for any reason, but the reason must be recorded in the patient's Case Report Form if the cause is known.

Inclusion Criteria:

• Patients > 18 years undergoing elective surgical treatment in the liver, esophagus/cardia, or pancreas, according to the protocol with curative intent.
• Patients who can read and understand the Danish language.

Exclusion Criteria:

• Patients who are cognitively disabled and cannot mentally cooperate with the study design, as assessed by the investigator.

In accordance with the Declaration of Helsinki, patients have the right to withdraw from the study at any time for any reason

Patients who have undergone surgery in the pancreas, hepar or esophagus/cardia at Copenhagen University Hospital, Rigshospitalet

I do not need to share the IPD with other researchers