Evidence Based Dentistry

Question 1

What aspects make up evidenced based dentistry?

Answer 1

• PICO
• information literacy
• study design & interpretation
• critical appraisal
• systematic reviews

Question 2

What are systematic reviews?

Answer 2

type of literature review that uses systematic methods to collect secondary data, critically appraise research studies & synthesise studies

Question 3

Why are systematic reviews beneficial compared to reading single studies?

Answer 3

• saves readers time
• provide reliable evidence without bias
• resolve inconsistencies
• identify gaps
• identify when questions have been fully answered
• explore differences between studies

Question 4

What are the key characteristics of a systematic review?

Answer 4

1. well formulated question
2. comprehensive data search
3. unbiased selection and abstraction process
4. assessment of papers
5. synthesis of data

Question 5

How do non-systematic reviews differ from systematic reviews?

Answer 5

Non-systematic reviews are susceptible to bias

Question 6

List the evidence gathering methods from strongest to weakest:

Answer 6

1. systematic reviews & meta analysis
2. RCTs
3. cohort studies
4. case-control studies
5. cross-sectional studies
6. ecological studies
7. case series and case reports
8. ideas, editorials and opinions

Question 7

Why are systematic reviews important?

Answer 7

• reduce large quantities of info into manageable portions
• formulate policy & develop guidelines
• efficient use of resources
• increased power/precision
• limit bias and improve accuracy

Question 8

How are authors picked when performing a systematic review?

Answer 8

• 2 or more authors
• topic expert
• methodological expert

Question 9

What should be used to create the specific questions of systematic reviews?

Answer 9

PICO
- population
- intervention
- comparison
- outcome

Question 10

What search strategy should be used when creating a systematic review?

Answer 10

• comprehensive & repeatable search
• multiple electronic databases
• published & unpublished literature
• ideally without language restrictions

Question 11

Give an example of a global independent network that summarises healthcare evidence:

Answer 11

Cochrane

Question 12

What does PICO mean?

Answer 12

Participants
- who is the review interested in studying

Interventions
- what is the intervention or group of interventions or interst

Comparisons
- what will the interventions be compared to

Outcomes
- which outcomes will tell you which intervention is most effective

Question 13

What can be used to gather a comprehensive data search when forming a systematic review?

Answer 13

• electronic databases
• reference lists
• hand searching
• multiple languages
• sources of ongoing and/or unpublished studies

Question 14

How might you know if a positive result study has experienced bias?

Answer 14

These studies with positive results are:
- more likely to be published [publish bias]
- more likely to be published rapidly [time lag bias]
- more likely to be published in English [language bias]
- more likely to be cited by others [citation bias]

Question 15

Give examples of quality assessment tools that can be used to assess papers when formulating a systematic review:

Answer 15

• composite scales
• component approach

Question 16

When assessing RCTs for bias, what should be investigated?

Answer 16

• sequence generation
• allocation concealment
• blinding
• incomplete outcome data
• selective outcome reporting
• other

Question 17

What is meta-analysis?

Answer 17

• the process of using statistical methods to combine the results of different studies
• aim is to integrate findings, pool the data, and identify the overall trend of results

Question 18

What are the advantages of a meta-analysis?

Answer 18

• increase in power
• improvement in precision
• ability to answer questions not posed by individual studies

Question 19

What are different types of data categorised into and give examples of each:

Answer 19

Dichotomous
- illness or not/death or not/birth or not

Continuous
- blood pressure/weight/amount of pain

Question 20

What system does Cochrane use to asses the confidence of results in meta-analysis?

Answer 20

GRADE
- Grading of
- Recommendations Assessment
- Development and
- Evaluation

Question 21

Using the GRADE system, what are 5 factors that can lower quality of meta-analysis results?

Answer 21

• high or unclear risk of bias
• inconsistency between studies
• indirectness [was PICO used?]
• imprecision [numbers & confidence intervals]
• publication bias

Question 22

What is the process of creating a systematic review?

Answer 22

• 2 or more authors
• study protocol
• specific question using PICO
• search should be comprehensive and repeatable, multiple electronic databases, published & unpublished
• inclusion/exclusion criteria
• critically appraised