evidence based decision making n concept of critical appraisal

Sumandeep Vidyapeeth_20151

Dr Monali ShahProfessor, Dept of Periodontology

Steps Of Evidence Based Decision Making And Concept Of Critical Appraisal


Evidence based health careEvidence based practice in health

care industry is relatively new philosophy of clinical practice and a life long learning, which emphasizes a systematic and rigorous assessment of evidence for use in decision making in health care.


1. 2. 3. 4. of Evidence Based Practice 0NE Goal

– improve health of people through high quality care

TWO principles– Evidence has hierarchy - Evidence alone is not important

THREE components- Evidence - Expertise - Expectation

FOUR steps- Ask - Acquire - Appraise -Apply


Patient-Doctor Dyad – Not really changed through time

The point at which effecting Doctor-Patient communication and planning is informed by the best evidence

Three interacting realms of EBD


“Best Research Evidence” BEST means high level evidence with valid

study design and clinically effective results which can be applied locally


“Clinical expertise”Expertise in :

Noting signs and symptomsTaking a good historyInterpreting results of testsThinking analytically


“Patient Values”

Time consumption Living arrangements Working arrangements Medical care vs. other goods and services Cost of therapy


Evidence based decision making in health care Ultimately lead us to shared decision


Process Of Evidence Based Decision Making:

1. Asking specific relevant answerable questions2. Searching for the best evidence3. Reviewing and critically appraising the evidence4. Applying this information in a way to help the clinical

practice.


The evidence based practice can be divided into the following components:

Identifying area of uncertaintyAsking a relevant, focused, clinically important question that is answerable Selecting the most likely database for search Searching and appraising the evidence found Assessing the clinical importance and applicabilityActing on and appropriately applying the evidenceAssessing the outcomes of your actions and storing

the data


Formulating answerable question


Most fundamental/structured question A good question

Information needs and problems

(P) Problem

OR information required --who or whom

(I) Intervention --what

( C) comparison –other option well

established* better

or not

(O) outcome --what u want to

investigate


Most common type of questions:

Type of study:

Diagnosishow to select and interpret diagnostic tests

prospective, blind comparison to a gold standard or cross-sectional

Therapyhow to select treatments that do more good than harm and that are worth the efforts and costs of using them

randomized controlled trial > cohort study

Prognosishow to estimate the patient’s likely clinical course over time and anticipate likely complications of disease

cohort study > case control > case series

Harm/Etiologyhow to identify causes for disease

cohort > case control > case series


HOW TO FIND CURRENT BEST EVIDENCE?

If you don’t find evidence does not mean evidence is not there…..??


Searching is a skill


Critical appraisal…?

Learn how to find out what not to believe that is

published

Critical appraisal will help us to decide whether reported piece of research Is good enough to be used in decision making


What is critical appraisal Critical appraisal is the process of carefully and

systematically examining research to judge its

trustworthiness, its value and relevance in a particular

context. (Burls 2009)


Various check list for critical appraisal

CASP www.sph.nhs.uk/what-we-do/public-health-

workforce/resources

SIGN guideline developer’s handbook

http://www.sign.ac.uk/guidelines/fulltext/50/annexc.html

CEBMH

http://cebmh.warne.ox.ac.uk/cebmh/education_critical_app

raisal.htm


Critical appraisal

Relevance assessment

Validity assessment

Results assessment

Application assessment and application


Relevance assessment Determine whether the study is relevant to your clinical

question. Need to compare your PICOT with research PICOT

Clinical question Research question

P 25 years healthy female Healthy adultsI Powered brush Powered brushC Manual brush Manual brushO Plaque control and tooth

whiteningPlaque control, BOP, stains

T 6 months


Validity assessment


Different study designs need different approaches Surveys

*sampling technique*response rate

Cohort studies*appropriate cohort identified*adequate follow up

Randomized controlled trials*random and concealed allocation*blinding*loss to follow up


Validity assessment (For RCT)Randomized assignmentRandomization concealedBlinding Both group treated equallySufficiently long follow upGroup similar at start of the study


Validity assessment (For Systematic review and meta analysis)1. Did the systematic review address a focused

clinical question?

2. How detailed and exhaustive was the search for studies?

3. How high was the quality of the selected studies?

4. Data handling, publication bias and heterogeneity


Results – size does matter


Result assessment Magnitude of the result Precision of the result Clinical Vs statistical significance

Did the new treatment/intervention make any difference, if yes, is it real, if real, what is the effect???


What does it tell us? P value Confidence interval Odds ratio Relative risk NNT


Lets visit forest plot


HeterogeneityHeterogeneity can be assessed using the “eyeball” test or more formally with statistical tests. With the “eyeball” test one looks for overlap of the confidence intervals of the trials with the summary estimate.

Are the results similar across studies? 3 tests

Eyeball” test – do they look same?Test of “Null hypothesis” for no

significant variation (p-value)Proportion of variation not due to

chance (I2)


Clinical Significance Clinical significance is always debated. The

statistically significant results may or may not be of

any clinical importance or value.


Applying Evidence to Individual Patient


Application Similar Patients

Are your patients similar to those in the study? Are they so different that the results can’t help yo How much of the study effect can you expect for

your patients?

Heneghan, Carl and Badenoch, Douglas. Evidence-Based Medicine Toolkit, 2nd edition. Oxford: Blackwell Publishing: BMJ Books. 2006, p. 71.


Application Realistic Interventions

Is the intervention realistic in your setting? Does the comparison intervention reflect your

current practice What alternatives are available?



Application Right Outcomes

Have all the right outcomes been considered? Are the outcomes appropriate to your patient? Does the intervention meet their values and

preferences?



What is shared decision-making? Patient and clinician share

information with each other (clinician shares medical information, patient shares personal knowledge of illness and values)

Participate in a decision-making process

Agree on a course of action

Sheridan et al Am Jrnl Prev Med 2004


We do not need study evidence on everything !

We have to catch him up!

But this ain‘t evidence-based.

evidence based decision making n concept of critical appraisal

Health & Medicine