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Accrual Reporting

An accrued subject or enrolled participant is defined by "a participant's, or their legally authorized representative’s, agreement to participate in a clinical study following completion of the informed consent process. Potential participants who are screened for the purpose of determining eligibility for the study, but do not participate in the study, are not considered enrolled unless otherwise specified by the protocol” per Protocol Registration Data Element Definitions for Interventional and Observational Studies.  

For national, externally peer-reviewed and institutional trials, in general, the Lead Organization listed on the trial in CTRP reports accrual.

Accrual data will be entered by NCI into the Clinical Trials Reporting Program (CTRP) for trials managed by

  • NCI Cancer Therapy Evaluation Program (CTEP), e.g., NCTN trials
  • NCI Division of Cancer Prevention (DCP), e.g., NCORP trials
  • NCI Center for Cancer Research (CCR)

Interventional Trials: Participant accrual reports are required no less than quarterly. Reports should be submitted as soon as possible after the cut-off date at the end of the quarter, but no later than 30 days after the cutoff date. The schedule for accrual reporting of interventional trials is as follows:


Cut Off Date

  • March 31
  • June 30
  • September 30
  • December 31

Due Date

  • April 30
  • July 31
  • October 31
  • January 31

Observational Studies: Accrual is required at least annually; if the trial is multi-institutional, more frequent reporting will help ensure accuracy of participating site enrollment.

Subject: Subject accrual also known as patient-level accrual is reported for national, externally peer-reviewed, and institutional trials. Subject accrual data includes:

  • Study Identifier (e.g., Lead Org, NCI, CTEP, or DCP Protocol ID Number)
  • Participating Site Identifier
  • Study Subject Identifier
  • Zip Code (if U.S.)
  • Country
  • Date of Birth (MM/YYYY)
  • Sex (Biological sex assigned at birth)
  • Ethnicity
  • Race(s)
  • Registration Date
  • Disease Code
  • Disease Site Code (only for subjects reported with ICD-O-3 disease coding)

Please note zip code and country should be reported based on the subjects' place of residence (not the participating site).

Partial Subject: Partial Subject accrual is reported when full Subject/Patient-Level accrual reporting has not been collected because of the scientific design of the trial. At a minimum, Partial Subject accrual data includes:

  • Participating Site Identifier
  • Study Subject Identifier
  • Registration Date

Note: All other accrual data fields are optional when reporting via Partial Subject accrual. CTRP encourages submission of any other data elements when available.

* The reporting of Partial Subject accrual on a Complete Interventional trial requires approval. Please submit the request to CTRO ( For additional information on the reporting of Partial Subject accrual, please visit or submit an inquiry to CTRO (

Summary: Summary accrual, or the cumulative participant count, is reported for industrial trials as well as for multi-institutional trials (whose lead organization is not an NCI-Designated Cancer Center. For these trials, each participating site reports its own summary accrual data.

  • Updated: