Identifying Evidence Gaps

The Task Force identifies and reports on evidence gaps for each clinical preventive service it reviews. Special attention is given to those areas where evidence is needed to make recommendations for specific populations and age groups. The Task Force highlights these research gaps in each of its recommendations statements as well as in an annual report to Congress. The Task Force hopes that by highlighting evidence gaps it will assist public and private researchers and research funders in targeting their efforts, ensuring a collaborative approach to improving preventive health care for all Americans.

Prevention TaskForce Tool

A complete list of USPSTF I statements can be found using the Prevention TaskForce, an application that includes all final Task Force recommendation statements and is designed to help primary care clinicians identify the right clinical preventive services for their patients.

Evidence Gaps in Recommendation Statements

There are two ways that the USPSTF highlights evidence gaps in its recommendation statements:

  • Issuing an “I statement.” The USPSTF issues an “I statement” when there is not enough evidence or when the available evidence is of poor quality or conflicting. As a result, the USPSTF is unable to assess the balance of benefits and harms and cannot make a recommendation for or against providing the preventive service.
  • Describing the “Research Needs and Gaps.” When the USPSTF issues a recommendation for or against providing a service (i.e., an A, B, C, or D grade), it also points out where gaps in the evidence remain. This is described in each recommendation statement in a section called “Research Needs and Gaps.”

Annual Report to Congress

As requested by Congress, each year the USPSTF issues the “Annual Report to Congress on High-Priority Evidence Gaps for Clinical Preventive Services.” This annual report identifies gaps in the evidence base for clinical preventive services and recommends priority areas that deserve further examination.

Research Gaps Identified by the Office of Disease Prevention

The USPSTF works with the National Institutes of Health (NIH) Office of Disease Prevention (ODP) to disseminate information about evidence gaps to the research community. The NIH and other funding agencies and organizations use this information to help identify where more research is needed. The NIH ODP lists the USPSTF I statements in the Research Needs and Gaps section on the ODP website.


Current as of: February 2021
Internet Citation: Identifying Evidence Gaps. U.S. Preventive Services Task Force. June 2018.