COG Data Sharing


Consistent with the policies of the National Institutes of Health, COG considers requests from investigators who are not members of COG and to make its research data available to them. Investigators who wish to use individual patient data from one or more COG studies must make a formal request to the Group. The formal request must be in the form of a brief proposal as outlined below. The Group will then review the scientific merits and feasibility of the request.

Note: Requests for data will ordinarily be considered once the primary study analyses have been published. Nevertheless, consideration of requests for data will be entertained in the event that there are long delays in the publication of the primary study data.

Please submit a completed COG Database Project Request Form to:

The Group will conduct an internal review of the merit and feasibility of the proposal, including whether there are sufficient data to provide adequate information for analysis and if the required data are available. Investigators will be notified of the Group’s decisions in writing within 6 weeks of receipt. If a request is denied, COG, in the written decision, will provide the reasons the request was denied and inform the investigators that a denied request may be appealed as outlined in the appeals process section below. Release of the data is subject to the conditions outlined in release conditions below.


Release of data for research purposes is subject to the following conditions. A formal Data Use Agreement (DUA) covering the relevant conditions will usually be required.

  • Investigators must agree to use the data only for the approved research project. If the investigator later wishes to use the data in a new project, a new proposal must be submitted. Use of data for purposes not expressly authorized by the approved research project constitutes a breach of the agreement.
  • Investigators must agree to keep the individual patient data confidential. The data may only be shared within the team conducting the analysis project. Requests from other individuals for access to the data must be refused and referred to the COG.
  • The regulatory requirements discussed in the Regulatory Considerations section of the COG Data Sharing Policy must be met.
  • In situations where a complex data set is required, a fee may be charged.
  • Copies of all manuscripts arising from the project associated with the data request must be sent to COG for review. However, approval of the manuscript is not a condition for use of the data.
  • If the data are being provided for a project being conducted by a COG investigator, then all other relevant COG Group policies apply, particularly those relating to authorship and review of abstracts and manuscripts. If the data are being provided for an independent (non-COG) project, then there is no expectation that members of COG have authorship, unless COG members have made substantial contributions to the project.
  • Release of data collected in a clinical trial conducted under a binding collaborative agreement between the NCI Cancer Therapy Evaluation Program (CTEP) and a pharmaceutical/Biotechnology Company must be in compliance with the terms of the binding collaborative agreement and must be approved by CTEP and the company. Release of the data is also subject to the terms of any contracts between COG and other entities, which cover any of the requested data.
  • In releasing the data, COG makes no representations and extends no warranties of any kind, either expressed or implied. There are no expressed or implied warranties of merchantability or fitness for a particular purpose, or that the use of the data will not infringe any patent, copyright, trademark, or other proprietary rights. No indemnification for any loss, claim, damage, or liability will be intended or provided.
  • Under no circumstances will any of the 18 identifiers delineated in the HIPAA privacy rule be provided (the complete list can be found at Dates, including dates of birth, diagnosis, registration, enrollment, treatment failure, death, etc. are considered identifiers and will not be provided. Instead time intervals required for analysis will be provided.

For all data sharing with investigators who are not members of COG, a project-specific identifier which is not the patient’s COG identifier will be provided which identifies the research subject. The COG Statistics & Data Center will maintain the record of the patient’s COG identifier and the project-specific identifier.


If a request for data is denied, the applicant may appeal the decision. The appeal will be reviewed by the COG Group Chair, NCI/CTEP’s program officer and an outside statistician (i.e., a statistician that does not work for COG). The outside statistician will be named jointly by the COG Group Chair and the NCI/CTEP program officer.