Maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH), CT.gov was created in response to a legal mandate to connect people with potentially life-saving therapies first outlined in the Food and Drug Administration Modernization Act (FDAMA) of 1997 and revised per the Food and Drug Administration Amendments Act (FDAAA) of 2007.
It is a dynamic public database of clinical trials and their results provided to and updated by the study Sponsor, Principal Investigator, or their delegate. Registration to the CT.gov is recommended prior to the first participant enrolled and updated in real time (within 30 days) with subsequent IRB approved protocol amendments or status changes.
CT.gov offers clinical trial participants, their family members, health care professionals, researchers, public health agencies, and the general public access to information on publicly and privately supported clinical studies on a wide range of diseases and conditions.
The National Clinical Trial (NCT) number is the unique identifier assigned by CT.gov. To receive an NCT number, the study must be successfully registered with to CT.gov. This has historically taken 2-14 days after submitting the record to CT.gov for review, but may take longer if CT.gov staff have any questions or comments.
CT.gov Registration records summarize the most recently approved study protocol and include:
CT.gov Results records include:
The full “History of Changes” can be viewed via. a link with that name located on the bottom of each public record. Once a study is registered, all historical entries are preserved.
In Spring of 2020, UW Health launched Study Finder, an online tool to help with participant recruitment. Study Finder curates studies that have CT.gov and OnCore records to populate study specific information. Potential participants can search for studies and contact the study team directly from Study Finder. Using study finder is optional.
UW CT.gov Specialists assist in all aspects of CT.gov registration, record maintenance, and results reporting. To maintain compliant public records, they:
No, this service is free of charge to UW-Madison study teams who would like assistance.
UW CT.gov Service Line, Clinical Research Office:
CT.gov Support, Office of Research Compliance:
The UW CT.gov Specialists offer an Introduction to ClinicalTrials.gov Presentation and one-on-one training to familiarize study teams with the Registration, Maintenance, and Results Reporting Requirements. CT.gov Specialists are available to present at graduate seminars in an effort to train future investigators. Please reach out via email to schedule a time
The “Study Sponsor” is responsible for registering the clinical trial to CT.gov. Industry-Sponsors are responsible for registration, maintenance, and results reporting to CT.gov in most cases.
UW-Madison Principal Investigators are responsible for ensuring CT.gov registration if one or more of the following apply:
Find the Elaborations of Definitions of Responsible Party and Applicable Clinical Trials here.
UW-Madison PIs who are responsible for registering clinical trials to CT.gov and are in need of a Protocol Registration and Results Reporting System (PRS) User account to do so, please contact the UW CT.gov Service Line
The Food and Drug Administration (FDA) requires that all “applicable clinical trials” (ACT) be registered to CT.gov within 21 days of the first participant’s enrollment. The FDAAA Decision Tree helps determine whether a study is an ACT. The UW has developed a query tool to assist study teams in determining whether or not a study involves FDA-regulated drugs and devices.
Yes, to honor the intent of CT.gov, we encourage all prospective human research studies to be registered to CT.gov whether or not they meet registration requirements. Once registered to the database, all record maintenance requirements apply.
Yes, a study can be registered and assigned an NCT number prior to IRB approval. In this case, the Oversight Section of the registration record should indicate the study has been submitted to the IRB pending approval. The Oversight Section and all other relevant information are required to be updated once the study is IRB approved.
Yes, a study can be registered to CT.gov at any time. Please note that Section 801 of the Food and Drug Administration Amendments Act (FDAAA 801) requires Applicable Clinical Trials to be registered within 21 days of enrollment of the first participant. In addition, the International Committee of Medical Journal Editors and other journals require registration of clinical trials prior to enrollment of the first participant.
See FDAAA 801 and the Final Rule for more information.
Once a CT.gov registration record is populated and the study team clicks ‘Entry Complete’, the UW CT.gov Specialists will review the record to ensure that it meets the Protocol Registration and Results System (PRS) Review Criteria. If the review criteria is not met, the CT.gov Specialists will work with the study team to edit the record prior to releasing it for PRS Review.
Once released, PRS reviews the study record. This review focuses on apparent validity (when possible), meaningful entries, logic and internal consistency, and formatting. Study teams may be asked to clarify items or make corrections to the record before publication.
Please note that the PRS review process may take up to 14 days.
Once the record is released, reviewed, and accepted by PRS review staff for publication, the NCT number is assigned and the record will be public within 2–5 business days.
The study is considered registered once it has received an NCT (National Clinical Trial) number. The NCT Number is assigned after the protocol information has been Released (submitted) by the Responsible Party and passed PRS Review. At that time an e-mail notification containing the NCT Number is sent to the CT.gov Record Owner and the last person to edit the record. The record will be available to the public on ClinicalTrials.gov within 2–5 business days.
The key date for registration compliance, however, will be the date upon which the record was released for PRS review.
The Anticipated Study Start Date is the estimated date on which the clinical study will enroll its first participant. The Actual Study Start Date is the date on which the first participant was enrolled.
The University of Wisconsin–Madison is the sponsor for all UW CT.gov records.
A participant is “Enrolled” when they, or their legally authorized representative, agree to participate in a clinical study by completing 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.
The date upon which the first participant is enrolled is the Actual Study Start Date.
The CT.gov Registration Record has a section for an Individual Participant Data (IPD) Sharing Statement. The IPD Sharing Statement is required at registration for research groups registering their trials to CT.gov for the purposes of future publication to journals that follow ICMJE guidelines (applicable for trials that began enrolling participants on or after 1/1/2019).
IPD refers to measurements collected from each research participant. It is distinct from aggregated data usually reported in journal articles or in the ClinicalTrials.gov results database.
An IPD Sharing Statement indicates the terms under which clinical trial data at the individual level is available to researchers who were not part of the original study team.
Find examples of IPD Sharing Plans.
ICMJE requires CT.gov records to indicate ‘Yes’ or ‘No’ to the ‘Plan to Share IPD’ question at initial registration. The option of ‘undecided’ is not acceptable. Update the registration record in real time with any subsequent changes to the IPD Sharing Plan.
The following is a UW example of an IPD Sharing Statement that works well as template language.
Record Owners and the last person who edited the record (often PRS administrators / UW CT.gov Specialists) will get a notification once the NCT number is assigned. CT.gov Specialist will send an email to the PI and relevant study contacts explaining the next steps:
If you use OnCore to curate data from your trial and you would like for us to manage your CT.gov record using OnCore, please contact us.
Public Records are required to be updated within 30 days if there is a change in Study Start Dates, Recruitment status, Primary and Study Completion dates, study contact information, and to reflect any IRB approved protocol amendments.
The record is required to be verified once a year to confirm all the information is current. Annual Verification is required even if there are no changes.
The date on which the Responsible Party last verified the information in the entire CT.gov record, even if no additional or updated information is being submitted.
To verify a study record:
The date the final participant was examined or received an intervention for the purposes of final collection of data for the primary outcome, whether the study concluded according to the pre-specified protocol or was terminated. In the case of clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is complete for all of the primary outcomes.
Once the study has reached the primary completion date, the Responsible Party must update the Primary Completion Date from Anticipated to Actual in the CT.gov record.
For Applicable Clinical Trials per FDAAA Law and NIH-funded clinical trials, Results will be due one year from the Primary Completion Date.
The date the final participant was examined or received an intervention for purposes of final collection of data for the primary and secondary outcome measures and adverse events (for example, last participant’s last visit), whether the study concluded according to the pre-specified protocol or was terminated.
Once the study has reached the study completion date, the Responsible Party must update the Study Completion Date to reflect the Actual study completion date.
Per the Revised Common Rule requirement, federally funded studies that meet the definition of a clinical trial must post one IRB-approved informed consent form (ICF) used to enroll participants to a publicly available website, such as CT.gov The informed consent form must be posted after the trial is closed to enrollment, but no later than 60 days after the last study visit by any participant. The purpose is both for transparency and collective improvement of their quality.
Please go through the timeline and funding source to decide if this study has a requirement for posting ICF on CT.gov.
Reporting summary results to CT.gov benefits a number of stakeholders including participants, the research community, the general public, journal editors, Institutional Review Boards, ethicists, users of medical literature, and policy makers by:
Results are required to be reported to CT.gov for:
The ICMJE does not currently require results reporting to CT.gov
Per the intent of the database, summary results are encouraged to be reported whether or not they are required by law or policy.
For Applicable Clinical Trials (ACTs), subject to FDAAA 801 and 42 CFR Part 11, results are required to be submitted to CT.gov no later than 12 months after the Primary Completion Date, defined as the date the final participant was examined or received an intervention for purposes of final collection of data for the primary outcome.
Timeline for results reporting
Follow the PRS Guided Tutorials for step-by-step instructions on entering study results.
CT.gov Specialists will start communication regarding results reporting 6-12 months prior to the result due date (results submitted, reviewed, and posted on public site). If the PI/study team wishes to use the free central service, the Participant Flow, Baseline Characteristics, and Adverse Events Sections of the Results Module may be ready to be populated at this time, even if data analysis for the Outcome Measures in ongoing.
Initial results review by CT.gov PRS takes 25 days. It is recommended to submit the initial results up to 2 months in advance of the due date to have enough time for review process and subsequent required corrections.
If PI/study team opts to populate the results module, the CT.gov Specialists will monitor the status to ensure the record remains compliant. Results will be pre-reviewed and recommendations made to study team before releasing the record for the CT.gov PRS review process.
Active communication between the study team and CT.gov Specialists is key for keeping records in compliance.