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Comparing the USPSTF and GRADE Approaches to Recommendations
- Diana B. Petitti, MD, MPH;
- Steven M. Teutsch, MD;
- Mary B. Barton, MD, MPP;
- George F. Sawaya, MD;
- Judith K. Ockene, PhD, Med; and
- Thomas DeWitt, MD
- From Arizona State University, Phoenix, AZ 85041; Los Angeles County Department of Public Health, Los Angeles, CA 90012; Agency for Healthcare Research and Quality, Rockville, MD 20850; University of California, San Francisco, San Francisco, CA 94143; University of Massachusetts Medical School, Worcester, MA 01655; and University of Cincinnati College of Medicine, Cincinnati, OH 45229.
IN RESPONSE:
The USPSTF welcomes this opportunity to further explicate the similarities and differences between the GRADE and USPSTF approaches to making recommendations.
Guyatt and colleagues explain that guideline panels that use the GRADE approach may decide not to offer a recommendation and to provide clarifying statements. We agree that GRADE thus accommodates the situation in which the USPSTF uses an I statement. However, the USPSTF “rules of evidence” dictate that an I statement must always be issued if a letter grade of A, B, C, or D cannot be assigned (1, 2). This occurs when the USPSTF judges that the evidence about health benefits and harms does not permit at least moderate certainty that the balance of health benefits and harms is favorable, that no net benefit exists, or that the harms of the intervention outweigh the benefits (3). The values and preferences that individual patients place on benefits and harms are not considered by the USPSTF when deciding whether to assign a letter grade to a recommendation. The USPSTF also does not consider the cost or cost-effectiveness of the service. These are important differences between the USPSTF and the GRADE approaches.
Guyatt and colleagues state that the importance of the outcome the intervention prevents and the burden of the intervention therapy are no different from benefits and harms. The USPSTF agrees that importance and burden could be conceptualized as benefits and harms, but not that they must be.
The USPSTF agrees with Guyatt and colleagues' interpretation of the implications of the USPSTF insufficient evidence publication (4)—that the differences between treatment and diagnosis on the one hand, and prevention on the other, may make GRADE less applicable to prevention decisions. The USPSTF believes that certainty of a net health benefit must be higher when asymptomatic persons are encouraged by their physician to undergo a preventive intervention than when patients seek help for a problem and are advised to undergo a diagnostic intervention or to partake of a treatment. We welcome Guyatt and colleagues' comment on the implications of this belief.
The USPSTF did not intend to imply that GRADE does not consider the 4 issues the USPSTF describes as pertinent to decision making in the face of insufficient evidence. The GRADE Working Group has published widely about its methods, and these publications describe the uses of information on burden of illness, cost, and use in the community (5–12).
The difference between the USPSTF and the GRADE approaches lies in the role that burden of illness, cost, and community use play in moving from evidence about net harms and benefits to suggested actions. For the USPSTF, the assignment of a letter grade to a recommendation carries a suggested action: “Do it routinely” (grades A and B), “Don't do it routinely” (grade C), or “Don't do it” (grade D) (1). Topics not assigned a letter grade—all topics with an associated I statement—do not have a suggested action.
It is our understanding that, in addition to information on the quality of evidence about net benefits and harms, GRADE could use information on patient preferences, burden of illness, cost, and use in the community to classify a recommendation as weak or strong. It is also our understanding that a GRADE classification as a weak or strong recommendation determines the linkage of the recommendation with suggested actions (5, 6). This is indeed a large difference between the USPSTF and GRADE approaches. We believe that the USPSTF approach to insufficient evidence is well suited to the needs of the primary care community, the public, and policymakers in the United States for topics in prevention. This does not mean that the USPSTF approach is applicable outside the United States or that it is applicable to diagnosis or treatment.
The USPSTF is aware of the important work that GRADE is doing to try to reduce inconsistencies among different approaches to assessing the quality of evidence and moving from evidence to recommended actions. The USPSTF and GRADE use nearly identical criteria to rate the quality of studies that provide information about health benefits and harms (2, 7–11). The USPSTF and GRADE both attempt to make their methods and processes transparent and to remain scrupulously free of financial conflicts of interests. The USPSTF looks forward to further productive dialogue about and convergence of the methods and processes of the USPSTF, GRADE, and other authoritative groups. We are eager to engage in an ongoing inquiry about how best to rate, review, and use evidence and about the kinds of evidence that should figure in suggestions for action.
Steven M. Teutsch, MD
Los Angeles County Department of Public Health
Los Angeles, CA 90012
Mary B. Barton, MD, MPP
Agency for Healthcare Research and Quality
Rockville, MD 20850
George F. Sawaya, MD
University of California, San Francisco
San Francisco, CA 94143
Judith K. Ockene, PhD, Med
University of Massachusetts Medical School
Worcester, MA 01655
Thomas DeWitt, MD
University of Cincinnati College of Medicine
Cincinnati, OH 45229
Article and Author Information
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Potential Financial Conflicts of Interest: None disclosed.
