# Presentation: 350414

## Evidence-Based Practice for Nurses  

- Judith Welsh, R.N., M.L.S.
- Clinical Informationist
- NIH Library

## What is evidence based practice?

- 	Evidence based practice is the conscientious use of current best evidence in making decisions about patient care (Sackett, Straus, Richardson, Rosenberg, & Hayes, 2000).  It is a problem-solving approach to clinical practice that integrates:
- A systematic search for and critical appraisal of the most relevant evidence to answer a burning clinical question
- One’s own clinical experience
- Patient preferences and values
- 	Bernadette Mazurek Melnyk and Ellen Fineout-Overholt, Evidence Based Practice in Nursing and Healthcare, 2005.

## Why Practice EBM?

-    “Unfortunately, a great deal of research reported in journal articles is poorly done, poorly analyzed or both, and thus is not valid. A great deal of research is also irrelevant to our patients and practices.”

- Robert J. Flaherty, MD.  A Simple Method for Evaluating the Clinical Literature.
- Family Practice Management, May 2004.

- From: Informed Health Online, April 2004, Greg Smith

## The EBM Process

- Five basic steps: 1. Formulating an answerable question
- 2. Searching for the best evidence
- 3. Analyzing the evidence
- 4. Applying the evidence to a particular patient
- 5. Evaluate the practice decision or change

## Step 1:Formulating an Answerable Question	

-       Converting the need for information (about prevention, diagnosis, prognosis, therapy) into an answerable clinical question.

## The Question:

- What is the effect of low-dose, diuretic-based antihypertensive treatment on major cardiovascular disease event rates in older non-insulin-treated diabetic patients with isolated systolic hypertension, compared with non-diabetic patients?
- Effect of diuretic-based antihypertensive treatment on cardiovascular disease risk in older diabetic patients with isolated systolic hypertension. Systolic Hypertension in the Elderly Program Cooperative Research Group.JAMA. 1996 Dec 18;276(23):1886-92. Erratum in: JAMA 1997 May 7;277(17):1356.

##  Break the Question down into component parts:  

- Patient or Problem
- Intervention
- Comparison intervention
- Outcome

## The Question : component parts

- Patient or Problem
- Older, non-insulin-treated diabetic patients with isolated systolic hypertension compared with non-diabetic patients
- Intervention
- Low-dose, diuretic-based anti-hypertensive treatment
- Comparison Intervention
- Placebo and any active anti-hypertensive drugs prescribed by patients’ private physicians for persistently high BP
- Outcome
- Decrease in major cardiovascular disease event rates

## The EBM Process

- Five basic steps: 1. Formulating an answerable question
- 2. Searching for the best evidence
- 3. Analyzing the evidence
- 4. Applying the evidence to a particular patient
- 5. Evaluate the practice decision or change

## Step 2: Searching for the Best Evidence

- University of Washington, HealthLinks, Evidence-Based Practice Tools Summary

## These models suggests that you start your search at the top of the pyramid with systematic reviews from the Cochrane Database of Systematic Reviews. Depending on the success of your search in Cochrane, work your way down the pyramid of resources in order of decreasing relevance/validity and increasing work, until you find an answer. Journal articles form the base of the pyramid on the left because they represent large amounts of "unrefined" information, and the burden of determining the validity and relevance is up to the user. 

- The Claude Moore Health Sciences Library, University of Virginia (text); The Claude Moore Health Sciences Library, University of Virginia and the University of Washington HealthLinks (graphics)

## The EBM Process

- Five basic steps: 1. Formulating an answerable question
- 2. Searching for the best evidence
- 3. Analyzing the evidence
- 4. Applying the evidence to a particular patient
- 5. Evaluate the practice decision or change

## Step 3:  Analyzing the Evidence

- First, determine the strength of the evidence.
- Based on a hierarchy of evidence:
- Results of systematic reviews of well-designed clinical studies
- Results of 1 or more well-designed clinical studies
- Results of large case series
- Expert opinion
- Personal experience

- Bigby, Michael. Evidence-Based Medicine in a Nutshell. Archives of Dermatology, December 1998.

## Step 3:  Analyzing the Evidence

- Then, analyze the evidence for validity.
- For questions about therapy:
- Did the groups have the same characteristics at the initiation of the trial?
- Were treatment assignments randomized?
- Were all parties involved blinded to the treatment?
- Was patient follow up complete?
- Were patients analyzed in the groups to which they were randomized?

## Analyzing the Evidence

- Two general approaches
- “Quick”
- “In Depth”

## “Quick” : Essential

- Were patients randomized to treatment?
- Were all patients entering the study accounted for at the end?
- Were patients analyzed in the groups to which they were randomized?

## “In Depth” : Time to Spare !

- Were patients and study personnel “blinded”?
- Were groups similar at the start of the study?
- Were study groups treated the same (aside from the intervention)?
- What is the precision (certainty) of the result?
- Expressed as Confidence Interval (CI) or P-value

## The EBM Process

- Five basic steps: 1. Formulating an answerable question
- 2. Searching for the best evidence
- 3. Analyzing the evidence
- 4. Applying the evidence to a particular patient
- 5. Evaluate the practice decision or change

## Step 4: Applying the evidence to a particular patient

- Can the study results be generalized to the patient?
- If the patient meets all study inclusion criteria
- If there is no biological reason why you should **not** generalize the treatment
- What is the risk v. benefit to the patient?
- Available data
- Judgment
- Are treatment benefits worth the effort?
- Number needed to treat : the lower, the better
- Patient’s values and preferences?
- Buy-in is imperative

## The EBM Process

- Five basic steps: 1. Formulating an answerable question
- 2. Searching for the best evidence
- 3. Analyzing the evidence
- 4. Applying the evidence to a particular patient
- 5. Evaluate the practice decision or change