Evidence Based Dentistry Revision Questions

Question 1

How to reduce bias

Answer 1

radomisation

double blinding

Question 2

What is the type of bias would blinding prevent

Answer 2

selective bias

Question 3

Role of epidemiology

Answer 3

assess peoples risk of disease
study of cases/determinants of disease
measurement of amount and distrubition of disease
health care needs assessment and service planning
development of preventitve programme

Question 4

Prevalence

Answer 4

number of disease cases in a population at a given time

estimates obtained from cross sectional studies

Question 5

Incidence

Answer 5

number of new disease cases developing over a speicfic period of time in a defined population
estimates obtained from longitudinal studies

Question 6

absolute risk difference

Answer 6

difference in risk between groups and creates a confidence interval
overlap 0 = insufficient evidence

Question 7

number needed to treat

Answer 7

number of patients you would need to treat to prevent one patient developing the disease
1/absolute risk difference

Question 8

risk ratio

Answer 8

overlap 1 = insuffiecent evidence

Question 9

Confidence interval

Answer 9

shows how confident you can be with an estimate - narrower the CI the better

Question 10

What is P-value

Answer 10

how likley to get a result like this if the null hypothesis was true
if null hypothesis was true, simpling variation would produce an estimate that is further away from the hypotheisis value

P value <0.05 - significant effect - reject null hypothesis
Larger P value - do not reject null hypothesis 0 insufficient eveidence

Question 11

Highest level of evidence study

Answer 11

Cochrane review (systemic review and meta analysis)
Systemic review of all RCTS

Question 12

Social Prescribing

Answer 12

health professionals link patients to support in the community to improve health and wellbeing

Question 13

Null hypothesis

Answer 13

general statement suggesting no statisitical significance in set of data

Question 14

Cohort study

Answer 14

participtants recruited to study and followed up over time

Incidence and causes of disease

Question 15

RCT

Answer 15

participtants allocated by chance to different interventions and following up

Question 16

Standards to improve reporting

Answer 16

Consort

Question 17

Key features of RCT

Answer 17

Blinding
Radiomisation
Control/comparison
Inculsion/exclusion criteria

Question 18

Case series report

Answer 18

description of medical history of one or more patients

lacks control group

Question 19

Cross sectional

Answer 19

oberservational study that analyses data collected from a population at specific point in time
recall biased group - e.g a survey

Question 20

Systemic review and meta Analysis

Answer 20

all the evidence for RCTs looking at effectivness of a particular treatment
require multiple RCTs to exist

Question 21

Case control study

Answer 21

People with the disease are matched to those without it and earlier exposure to different are compared
Lacks control group
Great for aeitiogy
Less robust than cohort studies