In September 2007, NLM’s ClinicalTrials.gov launched a new user interface, the first significant change introduced since February 2000. New features include the ability to highlight search terms, more display options, and additional capabilities for viewing studies and search results by topic. Improvements were also made to “Advanced Search” mode and the display by location on the world map. The changes are summarized below, and a Technical Bulletin article also describes the features and improvements included in the new interface, with numerous screen shot examples.

In addition to the new interface, new requirements for registration of clinical trials were legislated by the enactment of U.S. Public Law 110-85 on September 27, 2007. This law expands the types of clinical trials that must be registered in ClinicalTrials.gov, increases the number of data elements that must be submitted, and also requires submission of results data. There are penalties for non-compliance with the law. Clinical trials are registered via a web-based data entry system called the Protocol Registration System (PRS). PRS allows the registration of trials that are approved by a human subject review board (or equivalent) and conform to the regulations of the appropriate national health authorities. More information about the specific implications of the new law and the registration requirements, including links to an “NIH Fact Sheet” and “Guidance from NIH Office of Extramural Research” is available at: http://prsinfo.clinicaltrials.gov/fdaaa.html.

User Interface Overview
While the new interface enhances site functionality and navigation significantly, the core aspects of ClinicalTrials.gov have been preserved. The homepage provides explicit links for searching the database (Search for Clinical Trials) and for investigators to register studies (Investigator Instructions). A search box with four navigation links at the top right of each page has replaced the menu bar, allowing new searches for studies to be launched at any time. Pages are now organized by context-sensitive tabs, so that their labels and functions change as a search progresses from submitting search terms to viewing a list of results to reviewing summaries of individual studies. Search terms and synonyms are now highlighted and bolded in study records.

New ClinicalTrials.gov homepage

Display Options
The default display on the List Results page includes condition(s) and intervention(s) being studied. Click on “Display Options” (”+” icon or link), above the first study listing in the upper right-hand corner, to reveal sixteen data elements that may be displayed in addition to the study title, recruiting status, conditions and interventions. As an option is selected, the corresponding information appears underneath each study listing. After selecting the desired options click on “Hide Display Options” (”-” icon or link) in the upper right-hand corner to hide the menu while saving selections for the duration of the search session. The List Results page defaults to displaying all studies, regardless of recruiting status. To limit the list to display only studies recruiting participants, click on the “Hide studies that are not recruiting patients” link (left side of the page, directly above the first study listing.

Study Record
The “Tabular View” and “Contacts and Locations” tabs provide two new display options for viewing a study record. The default (labeled “Full Text View”) is similar to the study page on the previous version of the ClinicalTrials.gov site. Click on the “Tabular View” tab to see a tabular list of data elements, except for contact and location information. Click on the “Contacts and Locations” tab to view detailed contact information and study locations.

Viewing Studies by Topic and Category
“Studies by Topic” and “Study Topics” expand on the previous version’s “Listings” feature by allowing users to view all studies by four main categories: Conditions, Drug Interventions (new), Sponsors, and Locations. Within each main category, studies are grouped alphabetically or by “subcategories.” “Results by Topic” is similar to “Studies by Topic” and “Study Topics,” but accessed by tabs on the List Results page after a query has been submitted.

Additional Features
“Advanced Search” (previously “Focused Search”) is now accessible by a tab or a link on the Basic Search page. Advanced Search now includes the ability to limit search results based on recruitment status (open or closed to enrollment), study type (interventional, observational, expanded access), and date study record was first received by ClinicalTrials.gov. In addition, users can search for a specific study sponsor and search multiple locations at once (e.g., Arizona OR California OR Nevada). The function of Advanced Search can also be applied to a search result by selecting the “Refine Search” tab (previously “Search Within Results”) on the List Results page and the user’s original search term(s) will be retained. The map of study locations is enhanced and users can view the number of registered studies in different regions of the world for a specific search or for all studies in the ClinicalTrials.gov database.

Editor’s Note: This article was adapted from the NLM Technical Bulletin article mentioned above.