About FDA

Clinical Outcome Assessments (COA): Frequently Asked Questions

Clinical Outcome Assessments (COAs) and Available FDA Pathways to Seek Advice:

Additional Considerations:


What is a COA and what are the different types?

A clinical outcome assessment is a measure that describes or reflects how a patient feels, functions, or survives.

Types of COAs include:

  • Patient-reported outcome (PRO) measures
  • Observer-reported outcome (ObsRO) measures
  • Clinician-reported outcome (ClinRO) measures
  • Performance outcome (PerfO) measures

What pathways are available to seek advice on COA development and validation? 

CDER has two pathways for reviewing COAs:

  • The CDER COA Qualification Program or
  • Under an individual drug development program 

COA qualification is a regulatory conclusion that FDA finds the COA to be a well-defined and reliable assessment of patients’ symptoms, overall mental state, or how they function. The COA is only qualified within its context of use. Qualified COAs are made publicly available for drug developers to use without needing FDA to reconfirm suitability. Note, regulatory qualification is voluntary process; a COA does not need to undergo formal regulatory qualification to be used successfully in drug development to support labeling claims. To learn more, please review: CDER COA Qualification Program and CDER COA Qualification Program FAQs

For an individual drug product development program, CDER’s COA Staff is consulted on a case-by-case basis by the primary review team. COA staff provides advice to the team, who then issues final comments to the sponsor. COA Staff can be consulted by CBER, CDRH, and the Review Divisions within CDER’s Office of New Drugs. Using a COA for an individual drug product development program does not qualify the COA. A COA that has not undergone formal regulatory qualification within the CDER COA Qualification Program will continue to be reviewed within individual drug development programs.

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How do I seek advice on COA development and validation under the CDER COA Qualification Program?

We encourage you to review the following resources as they contain a wealth of information and helpful weblinks related to the program: CDER COA Qualification Program and CDER COA Qualification Program FAQs

How do I seek advice on COA development and validation under an individual medical product development program?

To locate the appropriate contact, please first consider the FDA center with jurisdiction over the medical product in question.

If necessary, the review division or center may then submit a formal consult request to CDER’s COA Staff.

Are there other means I can use to seek advice on COA development and validation?

Yes. You can request a Critical Path Innovations Meeting (CPIM) to seek general Agency input on COAs for a particular context of use outside of an individual medical product development program. CPIMs do not result in any formal agreements. For more information, please refer to the CPIM website.

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Additional Considerations:

Am I required to use ONLY qualified COAs for clinical trials?

No. While we believe there are benefits to using a qualified COA, you are not required to use a qualified COA to support a clinical trial endpoint. We encourage you to discuss with the appropriate FDA review division as early as possible on use of COAs in an individual drug development program.

Will you consider COA development approaches that differ from what is described in the guidance?

Yes. We are willing to consider COA development approaches that differ from what is described in the FDA Patient Reported Outcome (PRO) guidance.

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Page Last Updated: 02/13/2019
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