FIGURE 7-1 Monthly registration of trials on ClinicalTrials.gov. Presently, journal editors will publish papers only for registered trials. As indicated by the constant slope, even after this policy went into effect, the National Library of Medicine was capable of handling large increases in the number of trials registered.

SOURCE: Zarin, 2007.

intended to increase its value. Dr. Zarin discussed the resource challenges of what she identified as four components of Recommendation 4.11, noting that none of those components will be easy to implement:

• Expanded scope of mandatory trial registration—The system has yet to reach a steady state, and could readily handle an increase in the number of trials registered without requiring a significant budget increase (Figure 7-1). While the current budget for ClinicalTrials.gov is just over $3 million per year, the system taps the National Library of Medicine’s (NLM) $300 million annual budget for search engine capabilities, hardware, personnel, etc. Some key functions of the registry, however, would be affected by and could benefit from policy changes:

• Providing objective criteria for determining whether mandated trials are registered. Examples of criteria that would be easy to monitor include intervention type (e.g., drug trials), phase, and number of subjects. Examples of criteria that would be difficult to monitor include those that use subjective language (e.g., “serious conditions”).