Dental Public Health- Evidence-Based Practice: what is and what is not + Introduction to Critical Appraisal Skills & Tools

• 5. Assess the impact on practice and evaluate

  
  

  how can you assess the impact on practice and evaluate?


  The KT Clearinghouse provides a detailed checklist

  for clinicians to self-evaluate their performance in

  relation to the EBP task

  (https://ebm-tools.knowledgetranslation.net/).

  
  

  -> This includes self-assessment on the application on

  the 5As of EBP
• 4. Apply the evidence

  
  

  Clinical practice should be evidence-based, rather than evidence-driven.

  TRUE/FALSE

  TRUE.

  clinical practice should be informed by evidence
• 4. Apply the evidence

  
  

  how should you apply the evidence?

  • Review the evidence in the context of your clinical experience in the particular setting you are working

  in (e.g. is there anything that could affect patients'

  adherence and outcome)

  • Consider all current care protocols

  • Consider guidelines, e.g. NICE, SIGN

  • Need for an audit combined with feedback
• 3. Appraise the literature

  GRADE SYSTEM

  
  

  what does very low mean?

  We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect
• 3. Appraise the literature

  GRADE SYSTEM

  
  

  what does low mean?

  Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect
• 3. Appraise the literature

  GRADE SYSTEM

  
  

  what does moderate mean?

  We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
• 3. Appraise the literature

  GRADE SYSTEM

  
  

  what does high mean?

  We are very confident that the true effect lies close to that of the estimate of the effect
• 3. Appraise the literature

  
  

  what is the grade system?

  used to rate the certainty of evidence for a treatment efficacy from high to very low.
• 3. Appraise the literature

  broad fields of research

  
  

  what is determined in Causation?

  if there is a causal relationship

  → using cohort study or case-control study
• 3. Appraise the literature

  broad fields of research

  
  

  what is done in prognosis?

  following patients where disease is identified in early stages

  → using longitudinal cohort study , recently also RCT
• 3. Appraise the literature

  broad fields of research

  
  

  what is demonstrated in screening?

  the value of screening when applied at a population level

  → using cross-sectional survey
• 3. Appraise the literature

  broad fields of research

  
  

  what is tested in diagnosis?

  whether a test is valid and reliable

  → using cross-sectional survey, recently also RCT
• 3. Appraise the literature

  broad fields of research

  
  

  what is tested in therapy?

  The efficacy of an intervention

  → using RCT
• 3. Appraise the literature

  
  

  Although RCTs are considered a 'gold standard', why are not all questions answered by RCTs?

  • RCTs often have poor external validity

  • Quality matters! - a well conducted study provides better evidence than a poorly conducted trial
• 3. Appraise the literature

  
  

  Hierarchy of evidence diagram

  
• 3. Appraise the literature

  
  

  what is the heirachy of evidence for effectiveness of interventions?

  (from strongest to weakest)

  • Randomised controlled trial (RCT):

  - Systematic review of RCTs/meta-analysis

  - Multiple RCTs

  - At least one good RCT

  
  

  • Well-designed interventional study without randomisation

  
  

  • Cohort study

  
  

  • Case-control study

  
  

  • Cross-sectional survey

  
  

  • Case report
• 3. Appraise the literature

  observational (analytical) studies:

  
  

  describe cohort studies

  • Measures incidence of disease; identifying risk factors; looking at the causes of disease; looking at pathways; determining prognosis.

  • A defined group of people (the cohort) is followed over time (→ a longitudinal study).
• 3. Appraise the literature

  observational (analytical) studies:

  
  

  describe cross-sectional studies (analytical):


  • Measures prevalence of disease or risk factor in a defined population at a specific time

  • Presents a 'snap-shot' of what is happening at a particular moment in time
• 3. Appraise the literature

  observational (analytical) studies:

  
  

  describe case-control studies

  • Identify potential risk factors (possible causes) for a disease.

  • Compare people with a specific outcome of interest (cases) with people from the same source population but

  without that outcome ('controls'), to examine the association between the outcome and prior exposure.

  • Particularly useful when the outcome is rare. Example: oral cancer
• 3. Appraise the literature

  
  

  what are observational (analytical) studies?


  - cohort study:

  outcome determined some time after exposure/intervention

  
  

  -cross-sectional study (analytical):

  outcome determined at the same time as exposure/intervention

  
  

  - case-control study:

  outcome determined before exposure/intervention
• 3. Appraise the literature

  experimental studies:

  
  

  describe nonrandomised controlled trails


  • Comparing therapeutic methods

  • Group allocation is not random
• 3. Appraise the literature

  experimental studies:

  
  

  describe randomised controlled trails

  • Evaluating effectiveness of interventions

  • Demonstrating relationship between intervention and adverse event

  • Groups allocation at random

  • Parallel or cross-over design
• 3. Appraise the literature

  
  

  what are experimental studies?

  - randomised parallel group

  - randomised cross-over
• 3. Appraise the literature

  
  

  what are the two types of analytical study?

  - experimental:

  for randomly selected intervention

  
  

  - observational (analytical):

  for nonrandomly selected intervention
• 3. Appraise the literature

  
  

  what is a analytical study?

  used to test a hypothesis

  
  

  It answers questions about how/when/why the characteristics occurred.
• 3. Appraise the literature

  
  

  what are the two types of descriptive study?

  - survey (cross-sectional)

  - qualitative
• 3. Appraise the literature

  
  

  what is a descriptive study?


  used to describe characteristics of a population or phenomenon being studied.

  
  

  It does not answer questions about how/when/why the characteristics occurred. Rather it addresses the "what" question.
• 3. Appraise the literature

  
  

  what is internal validity?

  the primary requirement of an analytical study
• 3. Appraise the literature

  
  

  what is external validity?


  the primary requirement of a descriptive study
• 3. Appraise the literature

  
  

  what are two aims of a study?

  - descriptive

  - analytical (pico)
• 3. Appraise the literature

  
  

  what is Retrospective studies?


  data refers to past events and may be acquired from existing sources
• 3. Appraise the literature

  
  

  what is Prospective studies?

  data is collected forwards in time from the start of the study
• 3. Appraise the literature

  
  

  what are 2 different types of studies?

  - Prospective studies

  - Retrospective studies
• 3. Appraise the literature

  
  

  what is secondary research?

  summarises and attempts to draw conclusions from other primary studies
• 3. Appraise the literature

  
  

  what is primary research?

  collects data at first hand, directly from the patients/population
• 3. Appraise the literature

  
  

  what are the two types of research?

  - primary research

  - secondary research
• 3. Appraise the literature

  
  

  what are the E-learning units on critical appraisal available on KEATS?

  • Critical appraisal for evidence-based medicine

  • Evaluating and Appraising Your Sources (in development)

  • Finding and Evaluating Information (legacy module)
• 3. Appraise the literature

  
  

  what are examples of reporting guidelines?

  • CONSORT (2010) for RCTs

  • STROBE (2012) for observational studies

  • PRISMA (superseding QUORUM, Moher et al 2009) for systematic reviews
• 3. Appraise the literature

  
  

  what are reporting guidelines?

  they give an idea of what you should look for
• 3. Appraise the literature

  
  

  what are examples of critical appraisal tools?

  • Critical Appraisal Skills Programme (CASP)

  • The Centre for Evidence-Based Medicine

  • The Centre for Evidence-Based Dentistry UK