Development of a Core Outcome Set for the research and assessment of inoperable malignant bowel obstruction

Malignant bowel obstruction is experienced by 15% of people with advanced cancer, preventing them from eating and drinking and causing pain, nausea and vomiting. Surgery is not always appropriate. Management options include tube or stent drainage of intestinal contents and symptom control using medication. Published literature describing palliative interventions uses a broad range of outcome measures, few of which are patient-relevant. This hinders evidence synthesis, and fails to consider the perspectives of people undergoing treatment.

To develop a Core Outcome Set for the assessment of inoperable malignant bowel obstruction with clinician, patient and caregiver involvement, using COMET methodology (Core Outcome Measures in Effectiveness Trials).

A systematic review of clinical trials and observational studies, a rapid review of the qualitative literature and in-depth patient and clinician interviews were conducted to identify a comprehensive list of outcomes. Outcomes were compared and consolidated by the study Steering Group and Patient and Public Involvement contributors, and presented to an international clinical Expert Panel for review. Outcomes from the finalised list were rated for importance in a three-round international Delphi process: results of two survey rounds were circulated to respondents, and two separate consensus meetings were conducted with clinicians and with patients and caregivers via virtual conferencing, using live polling to reach agreement on a Core Outcome Set.

130 unique outcomes were identified. Following the independent Expert Panel review, 82 outcomes were taken into round 1 of the Delphi survey; 24 outcomes reached criteria for critical importance across all stakeholder groups and none reached criteria for dropping. All outcomes rated critically important were taken forward for re-rating in round 2 and all other outcomes dropped. In round 2, all outcomes were voted critically important by at least one stakeholder group. Round 2 outcomes were presented again at online consensus meetings, categorised as high ranking (n = 9), middle ranking (n = 7) or low ranking (n = 8). Stakeholders reached agreement on 16 core outcomes across four key domains: Symptom control, Life impact, Treatment outcomes, and Communication and patient preferences.

Use of this Core Outcome Set can help to address current challenges in making sense of the evidence around treatment for inoperable malignant bowel obstruction to date, and underpin a more robust future approach. Clearer communication and an honest understanding between all stakeholders will help to provide a basis for responsible decision-making in this distressing situation in clinical practice.