According to Dialog Solutions, “the ClinicalTrials.gov database on Dialog provides access the world’s largest collection of clinical studies. ClinicalTrials.gov is provided by the U. S. National Library of Medicine and holds registrations from over 389,000 research studies in 220 countries.”
A clinical study is a research study involving human volunteers that is intended to add to medical knowledge. There are two types of clinical studies: interventional studies, also called clinical trials, and observational studies. Both are included in this database, as are expanded access programs.
A clinical trial is essentially a test of an intervention such as a new drug, diet, device or lifestyle change on a condition (disease or illness) to find out if it is safe and effective in people. The description of the study is provided in full and in addition about 12% of the documents also present the results, in tabular form, of completed studies. Information about the study includes the condition, intervention, study design, phase, status, eligibility criteria, outcome measures, locations where the study is being conducted, sponsor, funding type, contact information, and more. The full-text of the study and specific indexing of the condition, intervention, outcome measures and several other study sections facilitate precise searching and accurate recall.
Value proposition for ClinicalTrials on DialogThe value proposition put forth by Dialog for launching this NIH-created database is the power of its search capabilities. Not only does it allow for full text searching, it boosts retrieval via its medical synonym dictionary, links to Clinical trial IDs in Embase, Medline, and other related content, and adds an alerting feature. Dialog Solutions has many pharmaceutical databases, all of which can be cross-searched with ClinicalTrials.gov. Additionally, cross-searching patent and news databases rounds out the full picture for clinical trials research. Full records, including the entire detailed description of the study with result tables, can be exported into MS Word, MS Excel, XML, PDF and other formats.
Dialog’s search interface includes fields specific to clinical trials, including study type, study status, phase of the trial, country, gender of the subjects, funder type, and study documents. Date searches are very detailed; you can search by publication date, updates, start date of the study, primary completion, study first posted, results first posted and last study update posted. Lookups can be done for condition, intervention and sponsor.
ClinicalTrials.gov on the webAt the standalone ClinicalTrials.gov on the web, the basic search lets searchers find a study by status, condition or disease, other terms (such as NCT number, drug name, or investigator name) and country. Advanced search adds study type, study results, status (recruitment and expanded access), and eligibility criteria. Targeted Search has fields for intervention/treatment, title/acronym, outcome measure, sponsor/collaborator, lead sponsor and study IDs. Additional criteria include phase, funder type, study documents, FDAAA 801 violations, results submitted and multiple date options.
In many ways, Dialog Solutions’ version of ClinicalTrials.gov mirrors the extensive fielding of the Advanced Search at ClinicalTrials.gov on the web. The main advantage to using the Dialog implementation is the power of full Boolean searching on the text of the studies and the ability to cross search the additional research databases on the platform. Combined with the full complement of Dialog Solutions databases, ClinicalTrials.gov offers research possibilities not obtainable with the free web database. However, for less taxing requests not requiring extensive research across multiple sources, the free web ClinicalTrials.gov will probably suffice.