Since ClinicalTrials.gov launched its updated web-based data entry system in September, 410 clinical trial results have been uploaded to the comprehensive website. In a speech at CHP/PCOR on Tuesday, the director of this enormous effort, Deborah Zarin, M.D., spoke about the progress of the site and the future of the database.

ClinicalTrials.gov allows a wide array of stakeholders-from the layperson interested in medicine to health industry insiders-to track the most up-to-date results of drug and device clinical trials happening across the United States and in 161 countries. Zarin emphasized that researchers who use information from clinical trials, such as CHP/PCOR researchers that conduct systematic reviews, are an important target audience. The U.S. National Institutes of Health (NIH) developed the database in collaboration with the Food and Drug Administration (FDA) under the 1997 FDA Modernization Act that aimed to increase the transparency of clinical trials, with the database making its public debut in February 2000.

Receiving over 40 million page views a month, ClinicalTrials.gov is a powerful search engine that contains 70,000 trials with 410 of these trials in the completed stage. The site strives to be painstakingly accurate, identifying possible code names for drugs (e.g. Sildenafil citrate trial results comes up under a Viagra search).

Zarin, also a senior scientist at NIH, walked the audience through the vast search fields in the database. A user can target the search by over a dozen of options-- from outcome measures to phase of clinical trial to who funds the trial to what age group, and so on.

With so many field entry requirements, Zarin's ClinicalTrial.gov team has to constantly monitor entries to ensure the quality of results reported. Zarin showed the audience examples of illogical entries-"500" entered in the "proportion" field, performance scores of 0-2 with no definitions for what each number represented-and made clear how much more accurate entries are when data providers meet with ClinicalTrials.gov personnel to walk through how to unerringly input their trial entries.

This accuracy is vital in a site that relies upon quantitative data to describe trial results- searches bring up comprehensive results tables from clinical trials but no verbalized conclusion. For the layperson who accesses ClinicalTrials.gov, a clinical trial table that teems with acronyms is that much more confusing when one of these tables inaccurately lists its study participants' average hours of sleep a night as "823." In a site with such a broad user base, ClinicalTrials.gov demands precision.

Zarin's team will see no slow-down of these barriers. In September of 2007, laws changed to require the reporting of trials for FDA-approved (or cleared) Phase II-IV drugs and devices trials. This expansion will continue in September when adverse events of approved drugs will have to be reported on the site. Further, some trials that aren't legally bound to report their trials-e.g. non-drug, non-device interventions-still choose to input their trial results, which ClinicalTrial.gov accepts.

The two informal presentations allowed the audience to ask questions about the future of the database and how it can fit into Stanford researchers' own work. By law, ClinicalTrials.gov must review ways to enhance the database every three years and Zarin encouraged CHP/PCOR members to attend NIH's April 20th public meeting to review the site.