EBP EXAM 1

evidence

collection of facts thought to be true

types of evidence

internal and external

EBP

a process involving the examination and application of research findings/reliable evidence that has been integrated with scientific theories

aims of EBP

1) enhance healthcare quality

2) improve patient outcomes

3) reduce costs

4) empower clinicians

steps of EBP

0) spirit of inquiry

1) formulate PICOT question

2) search for evidence

3) Critically appraise the evidence

4) integrate evidence with clinical experience and patient/family prefences

5) evaluate outcomes of practice change

6) disseminate outcomes of EBP change

PICOT

Patient population

Intervention/issue of interest

Comparison group

Outcome

Time for intervention to achieve outcome

best evidence source

systematic reviews & randomized controlled trials (RCTs)

barriers to EBP

lack of knowledge

time

resources

spirit of inquiry (0)

curiosity that sparks a clinical question and launches the EBP process

Melnyk Step 1

formulate a searchable PICOT question

Melnyk step 2

search for the best evidence & identify level

Melnyk step 3

critically appraise evidence (validity, reliability, applicability)

Melnyk step 4

integrate evidence with clinical expertise & patient values

Melnyk step 5

evaluate practice-change outcomes with clear metrics

Melnyk step 6

disseminate the results of the EBP change

facilitators to EBP

EBP education

mentorship

supportive leadership

positive beliefs

quantitative research

structured data collection yielding numeric data

• descriptive

• correlational

• quasi-experimental

• experimental

qualitative research

explores lived experience through words

• phenomenology

• grounded theory

• ethnography

mixed methods

combines quantitative and qualitative approaches in one study

independent variable

the presumed cause or predictor

dependent variable

the outcome being measured

confounder

a variable related to both exposure and outcome that can bias results

nominal level

data classified into categories with no inherent order (eg. blood type)

ordinal level

categories with a rank order but unqequal intervals (eg. pain scale 0-10

interval level

equal intervals with no true zero (eg, ºC body temp)

ratio level

equal intervals with a true zero (eg. weight in kg)

face validity

tool appears to measure what it intends on the surface

content validity

tool covers all facets of the concept being measured

construct validity

tool relates to similar constructs and diverges from dissimilar ones as expected

cronbach’s alpha

statistic of internal consistency; ≥ 0.80 desirable

type I error (alpha)

false-positive; rejects a true null hypothesis

type II error (beta)

false-negative; failing to reject a false null hypothesis

p-value

probability results are due to chance; ≤ 0.05 commonly accepted as significant

confidence interval (CI)

range that likely contains the true effect; narrower CI = more precision

statistical vs clinical significance

statistically significant results may lack meaningful impact on patient care

cross-sectional study

observational “snapshot” measuring exposure & outcome at one point in time

prevalence

proportion of a population with a condition at a given time

descriptive cross-sectional

simply describes prevalence within a population

analytical cross-sectional

compares exposures & outcomes measured simultaneously

serial cross-sectional

repeated snapshots on the same population at different times

odds ratio (OR)

odds of exposure among cases / odds of exposure among controls

OR > 1

positive association between exposure and outcome

OR < 1

exposure may be protective

strengths of cross-sectional

fast

inexpensive

multiple outcomes/exposures studied

limitations of cross-sectional

no temporality

cannot infer causality

sucsceptible to context bias

cohort study

prospective (or retrospective) study following exposed vs unexposed to outcome

case-control study

retrospective study comparing exposure history in cases (with disease) vs controls

relative risk (RR)

risk in exposed / risk in unexposed

RR > 1

exposure associated with higher risk

RR < 1

exposure associated with lower risk

odds ratio (case control)

approximates RR when disease is rare

hazard ratio (HR)

time-to-event comparison between groups in survival analysis

cohort advantages

estimates incidence

shows temporal relationship

good for prognosis

cohort limitations

large

costly

long follow-up

loss to follow-up bias

case-control advantages

efficient for rare diseases/outcomes

smaller sample

case-control limitations

recall bias

control selection challenges

newcastle-ottawa scale

tool to appraise selection, comparability, and outcome quality in observational studies

level 1 evidence

systematic review or meta-analysis of RCTs

level 2 evidence

randomized controlled trial

level 3 evidence

prospective cohort study

level 4 evidence

case-control or cross-sectional study

level 5 evidence

expert opinion/bench research

selection bias

flawed sample selection procedures

measurement bias

when measures are not valid/reliable OR are performed inconsistently between study groups

social desirability bias

biases that stem from desire to report favorable information

directional hypothesis

predicts the direction of a relationship

non-directional hypothesis

predicts the existence of a relationship

null hypothesis

postulates the absence of a relationship (support or reject the hypothesis)

appraisal

determines the usefulness of a study to patient care; published ≠ good quality

point prevalence

proportion of a population that has the characteristic at a specific point in time

period prevalence

proportion of a population that has the characteristic at any point during a given time period of interest

lifetime prevalence

proportion of a population who, at some point in life, has ever had the characteristic