Clista Clanton, MSLS, AHIP

August 27, 2009

Evidence-Based Practice

Evidence-Based Practice (EBP) requires that decisions about health care are based on the best available, current, valid and relevant evidence. These decisions should be made by those receiving care, informed by the tacit and explicit knowledge of those providing care, within the context of available resources.

Dawes, M., Summerskill, W., Glaszion, P., Cartabellotta, A., Martin, J., Hopayian, K. et al. (2005) Sicily statement on evidence-based practice. BMC Medical Education, 5. Retrieved 7/22/09 from http://www.biomedcentral.com/1472-6920/5/1

Evidence-Based Medicine

"Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.”

Sackett, D.L. et al. (1996) Evidence based medicine: what it is and what it isn't. BMJ 312 (7023), 13 January, 71-72.

Adapted from: Sackett D.L., Rosenberg M.C., Gray J.A., Haynes R.B., Richardson W.S. (1996). Evidence based medicine: what it is and what it isn't. BMJ, 312, 71-72.

Developing the Clinical Question Step 1: Formulate the clinical issue into a

searchable, answerable question. Step 2: Distinguish what type of question

you may have.

Background

Foreground

Experience with Condition

Background Questions

Background questions ask for general information about a condition or thing. A question root (who, what, when, etc) combined

with a verb. A disorder, test, treatment, or some other form of

healthcare.▪ What causes arthritis?▪ What is the recommended length of exercise for

pregnant women?

Background questions are typically answered by textbooks.

Foreground Questions

Foreground questions ask for specific knowledge about a specific patient with a specific condition.Are specific stabilization exercises any more

effective than general strengthening exercises for low back pain?

Are strengthening exercises contraindicated in people suffering from post polio syndrome?

Foreground questions are typically answered by databases that access the

research literature

Developing the question

Foreground questions usually have four components.

P = Patient population

I = Intervention

C = Comparison

O = Outcome

Patient population/disease The patient population or disease of interest- age- gender- ethnicity- with certain disorder (e.g., hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (e.g., smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no intervention/therapy- Prognostic factor B- Absence of risk factor (e.g., non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (e.g., death)

PICO: Components of an answerable, searchable question

Melnyk, B. M., & Fineout-Overholt, E. (2005). Evidence-based practice in nursing & healthcare : A guide to best practice. Philadelphia, PA: Lippincott Williams & Wilkins.

In patient with

[Patient/ Problem]

does

[Intervention]

or

[Comparison, if any]

affect

[Outcome]

In patients with chronic pain, does the use of progressive muscle relaxation lead to a lessening of pain? In patients with post polio syndrome, are strengthening exercises contraindicated?

Is the 6-minute walk test useful in assessing the functional capacity of COPD patients?

In patients with low back pain, are specific stabilization exercises or general strengthening exercises more effective?

Types of Questions Diagnosis: How to select a diagnostic test or how to interpret

the results of a particular test.

Prognosis: What is the patient's likely course of disease, or how to screen for or reduce risk.

Therapy: Which treatment is the most effective, or what is an effective treatment for a particular condition.

Harm or Etiology: Are there harmful effects of a particular treatment, or how these harmful effects can be avoided.

Prevention: How can the patient's risk factors be adjusted to help reduce the risk of disease?

Cost: Looks at cost effectiveness, cost/benefit analysis.

Qualitative: Helps to understand clinical phenomena with emphasis on understanding the experiences and values of patients.

Health Sciences Literature Primary – original

research Experimental (an

intervention is made or variables are manipulated)○ Randomized Control Trials○ Controlled trials

Observational (no intervention or variables are manipulated)○ Cohort studies○ Case-control studies○ Case reports

Secondary – reviews of original research Meta-analysis Meta-synthesis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial, commentary

Not used in EBP

Type of Question Suggested Best Type of Study

Therapy RCT > cohort > case control > case series

Diagnosis Prospective, blind comparison to gold standard

Etiology / Harm RCT > cohort > case control > case series

Prognosis Cohort study > case control > case series

Prevention RCT > cohort study > case control > case series

Clinical Exam Prospective, blind comparison to gold standard

Cost Economic analysis

Questions of therapy, etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review.

Hierarchy of Evidence

Case Series/Case Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis/Meta-synthesis

Animal Research/Expert Opinion

Start at the top and work your way down.

Systems

Computerized decision support

Summaries

Dynamed, ACP PIER, Clinical Evidence, EBP guidelines

Synopses

TRIP, ACP Journal Club

Syntheses

Cochrane Systematic Reviews, DARE, PEDro

Studies

PubMed, Scopus, CINAHL

Haynes RB. Of studies, summaries, synopses, and systems: the “5S" evolution of services for finding current best evidence. ACP Journal Club. 2001;134: A11–13.

Adapted from Haynes (2001)

Sources of Information Dynamed Cochrane Library TRIP PEDro National Guideline Clearinghouse PubMed Scopus CINAHL Google Scholar