Word Document

Question 1

• What type of study provides the highest level of evidence?

Answer 1

• Cochrane reviews which are systematic assessments of all the relevant randomised controlled trials (RCTs) which give the highest level of evidence.

Question 2

4 aspects of RCT

Answer 2

o Randomised double blind reduces bias
o Inclusion and exclusion criteria
o Randomisation facilitates statistical analysis
o Compares one treatment over placebo to investigate any statistical significance

Question 3

4 study designs

Answer 3

o Randomised control trials – effectiveness and efficacy of treatments
o Cohort studies – prospective study
o Case control studies – retrospective study
o Case study – one patient report

Question 4

What is incidence

Answer 4

o Is the number of new disease cases developing over a specific period of time in a defined population,
o Incidence rate = no of new cases of disease in a period/no of individuals in population at risk
o Incidence estimates are obtained from longitudinal studies or derived from registers

Question 5

What is prevalence

Answer 5

o Is the number of disease cases in a population at a given time
o Prevalence – no of affected individuals/total no of persons in population
o Prevalence estimates are obtained from cross-sectional studies or derived from registers which can relate to attributes to absence or presence of disease

Question 6

What is SIMD

Answer 6

• Scottish index of multiple deprivation which is an area based index which use a range of data to decide which neighbourhoods are most deprived by ranking data zones in order of deprivation from quantile 1 – most deprived to quantile 5- 10 – least deprived

Question 7

7 factors influencing deprivation

Answer 7

o Employment status
o Income
o Health and health care services
o Geographic access to services
o Crime
o Housing, living and working conditions
o Education, skills and training

Question 8

• What are the advantages of a split mouth study design?

Answer 8

• Both control and intervention group are exposed to same environment.
• Each of 2 treatments are randomly assigned to either the right or left halves of the dentition on the same environment.- It removes inter-individual variability from the estimates of treatment effect
• No carry over effect for intervention or outcome

Question 9

What are the disadvantages of a split mouth study design

Answer 9

• Patient can not be blinded
• Adds more bias into the reporting
• Incorrect reporting risk

Question 10

• What is confidence intervals?

Answer 10

• The range of values the absolute risk difference will take in the population
• 95 out of 100; the CL will contain the true population ARD
• CL should not overlap 0 = sufficient evidence
• CL overlaps 0 = null hypothesis (insufficient evidence)
• A narrow CL is better as the larger the sample the narrower the CL

Question 11

• What is a P value?

Answer 11

• Used to determine the significance of your results
• P value <0.05 means you reject the null hypothesis and your results are statistically significant

Question 12

• What is d3t, mt and ft

Answer 12

• D3t = decayed deciduous Teeth
• Mt = missing teeth (XLA due to decay)
• Ft = filled teeth

Question 13

• Name 3 reasons why d3mft graph shows a difference between 2 areas?

Answer 13

o Socioeconomic status of the area
o Ethnicity status
o Individual health board involvement

Question 14

• What does the 3 in d3 mean?

Answer 14

• Obvious decay into dentine of the tooth using visual methods only

Question 15

• At a population level, name 3 fluoride delivery methods?

Answer 15

o Water fluoridation
o School water fluoridation
o School milk initiative
o Fluoridated salt

Question 16

• What 3 interventions are done in Scotland on a population basis?

Answer 16

o Smoking ban in public areas
o School food policy
o Sugar tax
o Minimum wage/national living wage

Question 17

• What is PICO?

Answer 17

o Population:
Children with caries in primary teeth
o Intervention:
Hall technique used
o Comparison:
Compared with standard techniques
o Outcome:
Rate of failures

Question 18

• What is confidence intervals and relative risk?

Answer 18

Confidence intervals:
The range of values the absolute risk difference will take in the population
* 95 out of 100; the CL will contain the true population ARD
* CL should not overlap 0 = sufficient evidence
* CL overlaps 0 = null hypothesis
* A narrow CL is better as the larger the sample the narrower the CL
Relative risk:
It is the ratio of incidence rate in exposed groups to incidence rates in non-exposed groups
It is a measurement of proportionate increase in disease rates of exposed groups