Retrospective part completed, prospective part response too low

This study will answer the question what the practice variation is (in terms of efficiency) in primary colon surgery on patients of 75 years and above related to the application of different modalities of prehabilitation across the Netherlands.

Rationale: Prehabilitation has shown promising results in orthopedic, cardiothoracic and abdominal surgery. However, there is still a lack of data supporting cost-effectiveness of prehabilitation in colon cancer surgery in older patients. Therefore the Dutch guidelines still restrict prehabilitation for research settings.

Objective: This study will answer the question what the practice variation is (in terms of efficiency) in primary colon surgery on patients of 75 years and above related to the application of different modalities of prehabilitation across the Netherlands. Besides, it will show what service factors (including prehabilitation) determine the technical efficiency of primary colon surgery for these patients of 75 years and above.

Study design: This study is a multicenter observational study based on questionnaires and existing data sources, aimed at including 24 different hospitals, of which structural, process and outcome data related to prehabilitation and colon cancer surgery will be registered.

Study population: Patients aged 75 years and above, 10 per participating hospital, who underwent colon cancer surgery in one of the participating hospitals, where prehabilitation is or is not applied. All patients will be followed with questionnaires focusing on process and outcome measures for the hospital period and three months after discharge.

Intervention: Whether or not the intervention (prehabilitation) is judged as part of daily practice in a participating hospital is based on a predefined definition of oncological surgical prehabilitation. The care as given in a participating hospital is according to the local guideline and will not be changed for this study. According to our definition prehabilitation consists at least of a minimum of 2 weeks exercise therapy and a review of the patients nutritional status at least 2 weeks before surgery.

Usual care: Guideline based colon cancer surgery, without prehabilitation. Main study endpoints: Technical efficiency and service factors that determine this technical efficiency of primary colon cancer surgery. The results will be presented anonymously both for patients and hospitals (so there will not be carried out benchmark analyses per center).

Statistical analysis: Data Envelopment Analysis will be carried out. Factors that might explain variability in technical efficiency will be regressed on bias corrected DEA scores (via truncated regression). Ethical considerations: There will be no change in standard procedures in everyday care. The burden for participants is minimal.

Inclusion Criteria:

• Patients aged 75 years and above
• Scheduled for colon cancer surgery

Exclusion Criteria:

• Not receiving surgery
• Hematogenous metastasis
• Pretreatment; chemotherapy or radiotherapy
• Rectal cancer

Outpatients from the participating hospitals