Core Outcome Measures in Effectiveness Trials

Core Outcomes for Colorectal Cancer Surgery: A Consensus Study

General Information

Colorectal cancer (CRC) is a major cause of worldwide morbidity and mortality. Surgical treatment is common, and there is a great need to improve the delivery of such care. The gold standard for evaluating surgery is within well-designed randomized controlled trials (RCTs); however, the impact of RCTs is diminished by a lack of coordinated outcome measurement and reporting. A solution to these issues is to develop an agreed standard “core” set of outcomes to be measured in all trials to facilitate cross-study comparisons, meta-analysis, and minimize outcome reporting bias. This study defines a core outcome set for CRC surgery.

Methods and Findings
The scope of this COS includes clinical effectiveness trials of surgical interventions for colorectal cancer. Excluded were nonsurgical oncological interventions. Potential outcomes of importance to patients and professionals were identified through systematic literature reviews and patient interviews. All outcomes were transcribed verbatim and categorized into domains by two independent researchers. This informed a questionnaire survey that asked stakeholders (patients and professionals) from United Kingdom CRC centers to rate the importance of each domain. Respondents were resurveyed following group feedback (Delphi methods). Outcomes rated as less important were discarded after each survey round according to predefined criteria, and remaining outcomes were considered at three consensus meetings; two involving international professionals and a separate one with patients. A modified nominal group technique was used to gain the final consensus. Data sources identified 1,216 outcomes of CRC surgery that informed a 91 domain questionnaire. First round questionnaires were returned from 63 out of 81 (78%) centers, including 90 professionals, and 97 out of 267 (35%) patients. Second round response rates were high for all stakeholders (>80%). Analysis of responses lead to 45 and 23 outcome domains being retained after the first and second surveys, respectively. Consensus meetings generated agreement on a 12 domain COS. This constituted five perioperative outcome domains (including anastomotic leak), four quality of life outcome domains (including fecal urgency and incontinence), and three oncological outcome domains (including long-term survival).

This study used robust consensus methodology to develop a core outcome set for use in colorectal cancer surgical trials. It is now necessary to validate the use of this set in research practice.

Angus G. K. McNair ,
Robert N. Whistance,
Rachael O. Forsythe,
Rhiannon Macefield,
Jonathan Rees,
Anne M. Pullyblank,
Kerry N. L. Avery,
Sara T. Brookes,
Michael G. Thomas,
Paul A. Sylvester,
Ann Russell,
Alfred Oliver,
Dion Morton,
Robin Kennedy,
David G. Jayne,
Richard Huxtable,
Roland Hackett,
Susan J. Dutton,
Mark G. Coleman,
Mia Card,
Julia Brown,
Jane M. Blazeby


PLOS Medicine
Further Study Information

August 2010 - December 2014
Funding source(s):
This work was supported by the MRC ConDuCT-II Hub (Collaboration and innovation for Difficult and Complex randomised controlled Trials In Invasive procedures - MR/K025643/1). RNW was supported by an NIHR doctoral research fellowship.

Health Area

Disease Category

Disease Name
Colorectal cancer

Target Population

Age Range
18 - 100


Nature / type of Intervention


Consensus meeting
Delphi process
Nominal group technique (NGT)
Systematic review

Stakeholders Involved

Clinical experts
Consumers (caregivers)
Consumers (patients)

Study Type

COS for clinical trials or clinical research

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