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.

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

Examples of core outcome set and outcome-set work associated with Surveylet / Calibrum include:

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

A minimum data set / core outcome set development process in degenerative cervical myelopathy that identifies Surveylet / Calibrum.

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

Core outcome set support from planning to reporting

Use Surveylet with your own methodology team or ask Calibrum to help deliver the Delphi workflow. Agree on the support you need at each stage, including any final meeting and reporting deliverables.

Plan the Delphi study

Define stakeholder groups, outcome wording, rating scales, feedback, and consensus rules. Turn-key study services can support methodology planning and questionnaire development.

Run the survey and meeting

Complete Survey Care supports Surveylet setup and operations. A facilitated consensus meeting is separately scoped for outcome review, discussion, and further ratings.

Prepare the study outputs

Agree on the outcome-status summaries, stakeholder comparisons, tables, and methods documentation your team needs. Analysis and final reporting can be added to support your steering committee or manuscript.

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.

What should our team prepare before setup?

Provide the proposed study scope, candidate outcomes and definitions, stakeholder groups, draft protocol, and planned outputs. Confirm the rating scale, feedback approach, and consensus rules before launch. Our study design checklist helps organize these decisions.

Delphi support for core outcome set development