Evidence-Based Practice for Nurses

Assessment, Development, and Evaluation, known as GRADE, has been an

international effort to develop a universal system of evaluation (The GRADE

Working Group, 2017). The mission has been to consolidate the forces of

many reputable organizations and agencies, such as AHRQ, the Centers for

Disease Control and Prevention, the World Health Organization, and many

other professional societies within the United States and abroad (http://www

.gradeworkinggroup.org). GRADE is closely aligned with the Cochrane Col-

laboration. The GRADE system ranks the strength and quality of evidence into

four levels: (1) high, (2) moderate, (3) low, and (4) very low. The recommen-

dation is either (1) strong or (2) weak. Criteria of the GRADE system can be

accessed at http://www.gradeworkinggroup.org. The GRADE Working Group

has developed a free software application that uses a systematic approach to

grade the evidence and create a summary table with the findings.

When weighing evidence, nurses may be involved in discussions that involve

determining the clinical significance of the findings (Straus et al., 2011). Ques-

tions about diagnosis, therapy, prognosis, causation, harm, and etiology can be

discussed. Examples are provided in Table 15-2. It would not be unusual for the

discussion to include concepts such as relative risk, relative risk reduction, absolute

risk reduction, numbers needed to treat, and odds ratio. Definitions of these terms

are provided in Box 15-2. This content is included so that you can become familiar

with the terminology, not so that you become adept at performing calculations.

It should be noted that not all the rating systems discussed include a way to

rank qualitative studies. Melnyk (2004) noted that EBP must consider the inclu-

sion of qualitative studies when reviewing studies of merit, and those qualitative

studies should assume a step on the hierarchy ladder. The research findings

Diagnosis Queries the selection and interpretation of diagnostic tests

Therapy Examines therapeutic treatment(s) for healthcare problems and

their efficacy, cost, and potential harm

Prognosis Evaluates the course of treatment over time, any complications,

and overall prognosis

Causation/harm/etiology Looks at the causes of disease, including iatrogenic causes,

potential harm, and benefits

Other Questions may be written related to prevention, clinical

examinations, cost, point of contact, or patient/client data

Modified from Straus, S. E., Glasziou, P., Richardson, W. S., & Haynes, R. B. (2011). Evidence based

medicine: How to practice and teach it (4th ed.). Edinburgh, Scotland: Elsevier.

TABLE 15-2 Common Clinical Questions

KEY TERM

GRADE: Grades of

Recommendations,

Assessment,

Development,

and Evaluation;

international,

universal system for

evaluating evidence

412 CHAPTER 15 Weighing In on the Evidence