Throughout the course, you will see comments referring to the evidence behind guidelines and recommendations. Evidence-based recommendations and guidance are the result of a careful review of studies and discussion by a panel of subject matter experts. For TCCC, the subject matter expert panels include both Committee on TCCC members, and select invited subject matter experts from within both the military and civilian community, based on the specific interest area.

A common approach is the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system, which rates the quality of evidence, then balances that with the outcomes (desirable and undesirable) to provide a recommendation with a comment about the certainty of the evidence. But there are other similar methodologies used by professional organizations, as well.

The quality of the evidence looks at variables like the number of studies on the area of interest, any limitations of the study, biases, consistencies, sample sizes, and statistical strengths of the results, among other things. In general, randomized, controlled studies with statistically significant findings are graded higher and observational studies with equivocal to mildly significant findings are graded lower. And consensus subject matter expert opinions without observational (or randomized) studies are also graded lower.

But keep in mind, that in the absence of clear evidence from formal studies, the use of consensus opinions is considered a best practice, which should be accompanied by simultaneous research to study that area of interest and ultimately provide evidence to support that opinion or alter the recommendation.

Guyatt G, et al. GRADE guidelines: 1. Introduction – GRADE evidence profiles and summary of findings tables. J Clinical Epidemiology. 64(2011):383-394.

Guyatt G, et al. GRADE guidelines: 1. Introduction – GRADE evidence profiles and summary of findings tables. J Clinical Epidemiology. 64(2011):383-394.