A shared minimum set of outcomes for research and reporting

A core outcome set (COS) identifies a minimum group of outcomes to measure and report within a defined research scope. Studies can still collect additional outcomes. Agreeing a common set helps researchers compare findings and include outcomes important to patients, clinicians, and other stakeholders. The COMET Initiative explains the purpose and use of core outcome sets. COMET stands for Core Outcome Measures in Effectiveness Trials.

Delphi methods allow stakeholders to rate candidate outcomes, review group feedback, and reconsider their judgments. Specify the COS scope, stakeholder groups, inclusion and exclusion rules, and how any final consensus meeting will use the results. COMET provides COS-STAD development standards, COS-STAP protocol guidance, and COS-STAR reporting guidance to help plan and document this work.

Commission core outcome set Delphi support

Choose the work your team needs help delivering. Platform access, implementation support, methodology and questionnaire development, a final meeting, and a written report should be identified separately in the proposal.

Your team leads the study

Use Surveylet with your approved protocol and questionnaire. Add Complete Survey Care for configuration, testing, participant communications, and round operations within purchased hours.

Calibrum supports study delivery

Turn-key study services can cover Delphi planning, outcome wording, scales, feedback, setup, administration, and agreed analysis. Your investigators approve the scope, candidate outcomes, panel, and final decisions.

You need a meeting or report

Scope a facilitated consensus meeting and final analysis and report as required. Specify outcome-status tables, stakeholder comparisons, item revisions, and methods documentation.

For a proposal: send the condition and population, intended research use, candidate outcome list and its sources, stakeholder groups, anticipated panel size, round plan, deadline, and required deliverables. Identify who will lead recruitment, approve changes, and chair any final meeting.

Designed for outcome prioritization and stakeholder consensus

Stakeholder Group Management

Organize participants by stakeholder group, such as clinicians, researchers, patients, caregivers, policy leaders, or professional-society representatives.

Outcome Rating Scales

Use structured rating scales, such as 1–9 importance scales, agreement scales, feasibility scales, or custom rating frameworks.

Round-by-Round Feedback

Provide participants with group-level feedback, distribution summaries, and anonymized comments before they reconsider ratings.

Consensus Tracking

Monitor which outcomes meet inclusion, exclusion, or no-consensus thresholds based on predefined criteria.

Real-Time Delphi Options

Use real-time Delphi methods when the study design calls for faster iteration and participant access to updated group feedback.

Reporting-Ready Outputs

Export data and summaries for analysis, steering-committee review, consensus meetings, supplementary files, and manuscripts.

From long list to final core outcome set

Generate candidate outcomesCandidate outcomes may come from systematic reviews, interviews, focus groups, registry data, steering-committee input, prior COS work, or clinical expertise.

Prepare the Delphi surveyOutcomes are organized into domains, definitions are clarified, instructions are written, and rating scales are selected.

Recruit stakeholdersPanels may include patients, caregivers, clinicians, researchers, funders, professional organizations, regulators, or other groups affected by the research.

Conduct Delphi Round 1Participants rate the importance of each candidate outcome and may provide comments or suggest missing outcomes.

Provide structured feedbackParticipants receive feedback such as distribution of scores, stakeholder-group summaries, and comments from the prior round.

Conduct additional rounds or real-time iterationParticipants reconsider their ratings. Outcomes are tracked against predefined consensus rules.

Consensus meetingMany COS projects include a final meeting to review Delphi results and confirm the final core outcome set.

Reporting and disseminationThe study team reports the final COS, methodology, participant flow, response rates, consensus criteria, and outcome-selection process.

Core outcome set and related consensus applications

Clinical Trial COS

Define outcomes that should be measured and reported across clinical trials.

Observational Research COS

Support consistent outcome measurement in registries and observational studies.

Minimum Data Sets

Develop standard data elements and outcome domains for research and reporting.

Patient-Reported Outcomes

Prioritize outcomes that matter to patients, caregivers, and families.

Outcome Definitions

Build consensus around definitions, domains, and measurement concepts.

Consensus Meetings

Prepare results and summaries for final consensus meetings after Delphi rounds.

Selected COS-related references

Published examples help you assess relevance to your field. The studies below describe Surveylet / Calibrum use or related outcome-set workflows; the full reference list distinguishes the evidence for each. Software use does not establish that Calibrum designed or managed the entire study.

COHESION: Neonatal Encephalopathy

A core outcome set for the treatment of neonatal encephalopathy that explicitly identifies Calibrum / Surveylet software.

COSUTI: Uncomplicated Urinary Tract Infection

A core outcome set for interventions for uncomplicated urinary tract infection in adults, involving a systematic review, online Delphi survey, and consensus meeting.

Degenerative Cervical Myelopathy

The PLOS Medicine study reports a two-round Delphi survey using Surveylet (Calibrum) to prioritize core outcomes and data elements, with feedback by stakeholder group.

Neonatal Sepsis

A neonatal sepsis core outcome set publication that cites Calibrum.

Stillbirth Prevention and Bereavement Care

A meta-core outcome set for stillbirth prevention and bereavement care following stillbirth that reports use of Calibrum / Surveylet.

CREAT-ED: Older Adults in Emergency Departments

A core outcome set protocol for research with older adults in emergency departments using real-time Delphi methods.

COSAVRI: Acute Viral Respiratory Infections

A core outcome set protocol for pharmacological treatments in hospitalized patients with acute viral respiratory infections.

View Full Reference List

Questions about core outcome set studies

Can patients and clinicians take part in the same study?

Yes. Surveylet can organize participants into stakeholder groups so your team can examine their ratings separately and together. Decide in advance which groups to include and whether consensus must be reached within each group.

Can Calibrum support the final consensus meeting?

A separately scoped Live Consensus Session can support independent outcome ratings, anonymized feedback, discussion, and reconsideration. The steering group defines how the meeting will resolve remaining items and confirm the final set.

Can a systematic review inform the Delphi study?

Yes. Your review can supply candidate outcomes for stakeholder prioritization. Agree on definitions and how review findings and stakeholder suggestions will enter the questionnaire. Commissioning Delphi support does not automatically include conducting the systematic review.

Do we need to develop a new core outcome set?

First check for an existing set that fits your condition, population, and intended use in the COMET database. A project using an existing COS has a different scope from developing a new one. Discuss the need with your methodology lead before commissioning a Delphi study.

Delphi support for core outcome set development