What is

Maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH), 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 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. 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.

What is an NCT number?

The National Clinical Trial (NCT) number is the unique identifier assigned by To receive an NCT number, the study must be successfully registered with to This has historically taken 2-14 days after submitting the record to for review, but may take longer if staff have any questions or comments.

What information can I find on Registration records summarize the most recently approved study protocol and include:


  • Title, description, and design of the study (how many arms, randomization, masking, anticipated number of participants)


  • Study status (whether or not the study is actively recruiting participants)


  • Disease or condition studied


  • Intervention (for example, the medical product, behavior, or procedure being studied)


  • Outcome Measures


  • Requirements for participation (eligibility criteria)


  • Location(s) where the study is being conducted


  • Study contact information


  • Links to relevant information on other health websites, such as NLM’s MedlinePlus®for patient health information and PubMed® for citations and abstracts of scholarly articles in the field of medicine Results records include:


  • Participant Flow (the number of participants starting and completing each arm)


  • Baseline Characteristics (age, gender, race, ethnicity, location of participants per arm, and study relevant baseline measures)


  • Outcome Measures data


  • Adverse Events (all-cause mortality, serious adverse events, other adverse events)


  • Full Study Protocol and Statistical Analysis Plan, Informed Consent Form if required


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.

How can I use the database?

  • Find and view clinical studies. Conduct basic and advanced searches of study records; browse studies; and search studies by topic, country, or region. Search studies that have results posted. See the Find Studies section of the site.


  • Learn more about clinical research. Find out how clinical studies are conducted and who can participate. See Learn About Studies.


  • Use site tools and data. View statistics on registered studies or download study records for analysis.

Can enhance recruitment?

In Spring of 2020, UW Health launched Study Finder, an online tool to help with participant recruitment. Study Finder curates studies that have 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 Services

What services does the UW Service Line offer?

UW Specialists assist in all aspects of registration, record maintenance, and results reporting. To maintain compliant public records, they:


  • Generate PRS User accounts for PIs and study team members


  • Register clinical trials (or review registrations) on behalf of PIs and study teams


  • Monitor Initial IRB Approvals and protocol amendments in ARROW to assist PIs and study teams in keeping public records up to date


  • Assist PIs and study teams with routine public record maintenance and requirements such as study status changes and annual verification of records ( Specialists can monitor OnCore records for this information)


  • Assist PIs and study teams with results reporting. PIs/study teams provide Summary Results, Final Protocol with Statistical Analysis Plan, Consent Form and any results related publications. PIs are responsible for record accuracy and approving the final submission.

Is there a fee for service from the UW Service Line?

No, this service is free of charge to UW-Madison study teams who would like assistance.

Who can answer my queries?

UW Service Line, Clinical Research Office:


  • Create Protocol Registration and Results Reporting System (PRS) user accounts to register trials to the public site.


  • Assist study teams throughout the life cycle of record including registration, maintenance and results reporting. Support, Office of Research Compliance:


  • Can also create PRS user accounts


  • Audit studies for registration requirements


  • Follow up / facilitate non-compliant studies for the UW.


Does the UW Service Line provide training to new users?

The UW Specialists offer an Introduction to Presentation and one-on-one training to familiarize study teams with the Registration, Maintenance, and Results Reporting Requirements. Specialists are available to present at graduate seminars in an effort to train future investigators. Please reach out via email to schedule a time

Clinical Trial Registration to

Who is responsible for registration?

The “Study Sponsor” is responsible for registering the clinical trial to Industry-Sponsors are responsible for registration, maintenance, and results reporting to in most cases.


UW-Madison Principal Investigators are responsible for ensuring registration if one or more of the following apply:


  • The trial is a UW Investigator-Initiated Trial (IIT)


  • The trial is federally sponsored and UW-Madison is the only study site or the coordinating center


  • The UW Investigator holds the IND for the agent being studied or the IRB has determined the agent is IND exempt


  • The UW Investigator holds an IDE for the device being studied or the IRB has determined it to be of non-significant risk (NSR)


Find the Elaborations of Definitions of Responsible Party and Applicable Clinical Trials here.


UW-Madison PIs who are responsible for registering clinical trials to and are in need of a Protocol Registration and Results Reporting System (PRS) User account to do so, please contact the UW Service Line

Should I register my study to


  • Registration is required when any of the following are met:


The Food and Drug Administration (FDA) requires that all “applicable clinical trials” (ACT) be registered to 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.



        • NIH-funded clinical trial requires registration. NIH has a decision tree for determining if the study is a clinical trial.


My study does not meet registration criteria, can I still register?

Yes, to honor the intent of, we encourage all prospective human research studies to be registered to whether or not they meet registration requirements. Once registered to the database, all record maintenance requirements apply.

How do I get a PRS User account to register my study to

Email the UW Service Line to request a PRS user account.

Can I register my study to if IRB approval is pending?

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.

Can I register a study after it has started, has closed to accrual, or is complete?

Yes, a study can be registered to 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.

When does an NCT number get assigned?

Once a registration record is populated and the study team clicks ‘Entry Complete’, the UW 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 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.

When is my study considered registered to

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 Record Owner and the last person to edit the record. The record will be available to the public on 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.

What is the study start date?

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.

Who is the sponsor for UW Clinical Trials?

The University of Wisconsin–Madison is the sponsor for all UW records.

Who is the responsible party for UW Clinical Trials?

The University of Wisconsin should be listed as the responsible party for all UW records.

What does ``enrolled`` mean in the record?

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.

What is an Individual Participant Data (IPD) Sharing Statement?

The 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 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 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 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.


  • Will IPD be available to other researchers? Yes


  • What data will be shared? Individual participant data collected during the trial, after deidentification.


  • What documents will be available? Study Protocol, Informed Consent, Statistical Analysis Plan, Clinical Study Report


  • When will data be available? Beginning 9 months after publication of primary outcomes, ending 5 years from that date.


  • With whom will it be shared? Researchers whose proposed use of the data has been approved by an independent review committee identified for this purpose.


  • For what types of analyses? Independent verification of study outcomes or to conduct subsequent clinical research.


  • How will data be shared? Proposals should be directed to [PI email here]. If approved after review by regulatory counsel, requestors will enter into a formal data sharing agreement. Data will be shared via encrypted single-user file transmission protocol. Record Maintenance

What are the next steps after registration?

Record Owners and the last person who edited the record (often PRS administrators / UW Specialists) will get a notification once the NCT number is assigned. Specialist will send an email to the PI and relevant study contacts explaining the next steps:


  • If applicable, please enter Identifier number [NCT#] into OnCore > PC Console > Main > Details > NCT Number



  • Protocol amendments must be reflected in the public record within 30 days of IRB Approval


  • Study Status Changes must be reflected in the public record within 30 days of the change – open the ‘Study Status’ section of the record and


    • Update the Overall Status


    • Update the Anticipated/Actual Primary Study Completion (the data upon which the all data was collected to answer the Primary Outcome Measures)


    • Update the Anticipated/Actual Study Completion (the date upon which all data was collect to answer all outcome measures) dates – typically, last participant off study date – not IRB Closure date


  • NIH-funded studies: Please make sure the record is updated prior to annual reporting. NIH systems automatically source information from the record.


  • Upon change in status to ‘Active, Not Recruiting’ [or, ‘Closed to Accrual’ per OnCore] – all ‘Anticipated’ enrollment numbers must be changed to ‘Actual’ enrollment numbers in the ‘Study Design’ section of the record


  • Upon Actual Study Completion Date (last participant off study) – a blank consent form that was used to enroll participants may be uploaded to your record no later than 60 days after the last study visit by any participant to satisfy the revised Common Rule


  • If there are no other changes, the record will require annual verification. Confirm the record is up to date and complete annual verification in the study status section


  • The Results Module is due within one year of the Primary Completion date, as applicable.


  • PMIDs for subsequent results publications can be added to the Protocol Section


If you use OnCore to curate data from your trial and you would like for us to manage your record using OnCore, please contact us.

When does my record need to be updated?

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.

What is the record verification date?

The date on which the Responsible Party last verified the information in the entire record, even if no additional or updated information is being submitted.

How can I verify my record?

To verify a study record:



  • Open the record in question and review it for accuracy, selecting ‘Save’ for sections that are updated.


  • Click the ‘Study Status’ tab, select current date in the drop down of ‘Record Verification Date’. Click ‘Save’ to confirm the update.


  • Click ‘Record summary’ at the top left corner of the record.


  • Click ‘Entry Complete’. This will automatically send a notification to PRS administrators for review and release of the record for review.

What is the primary completion date?

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 record.


For Applicable Clinical Trials per FDAAA Law and NIH-funded clinical trials, Results will be due one year from the Primary Completion Date.

What is the study 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.

Is my study within the scope of the Revised Common Rule? When should I upload a consent form?

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 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.


  • This requirement applies to studies that received initial approval AFTER January 21, 2019 and for previously approved studies that have transitioned to the Revised Common Rule. This requirement DOES NOT apply to studies approved prior to January 21, 2019 that have not transitioned to the requirements of the revised rule (most previously approved studies will not have transitioned). Please refer to for “Transition of studies to Revised Common Rule”


  • Regardless of how many ICF versions existed during the course of the study, only one ICF must be posted (even if the study was conducted at multiple sites). The study team can decide which ICF version is posted so long as the chosen version was used to enroll participants.


  • The ICF that is uploaded should be blank and un-redacted. In very rare instances, the funding agency may require redaction of certain portions of the ICF.


Please go through the timeline and funding source to decide if this study has a requirement for posting ICF on Results Reporting

What is the goal of the Results Database?

Reporting summary results to 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:


  • Providing a public record of basic study results in a standardized format


  • Fulfilling an ethical responsibility to participants by directly demonstrating the results of their volunteer efforts are available to the research community to advance medical knowledge


  • Mitigating publication and outcome reporting biases


  • Facilitating systematic reviews and other analysis of research literature


Modified from Tse et al, 2009

Do I need to report clinical trial results?

Results are required to be reported to for:


  • Applicable Clinical Trials (ACTs) (subject to FDAAA 801 and 42 CFR Part 11) 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.



The ICMJE does not currently require results reporting to


Per the intent of the database, summary results are encouraged to be reported whether or not they are required by law or policy.

Is posting results to considered 'prior publication'?

Per ICMJE, reporting results in a tabular format to in compliance with FDAAA 801 is not considered ‘prior publication’.

What is the timeline for working on results?

For Applicable Clinical Trials (ACTs), subject to FDAAA 801 and 42 CFR Part 11, results are required to be submitted to 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. 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 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 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 PRS review process.


Active communication between the study team and Specialists is key for keeping records in compliance.