Statistics

Question 1

What is evidence based dentistry?

Answer 1

Systematic assessment of clinically relevant scientific evidence relating to patients oral and medical condition together with dentists clinical expertise and patients treatment needs and preference.

It is the gold standard in healthcare delivery

Question 2

What is critical appraisal?

Answer 2

Process of assessing and interpreting evidence through systematic consideration of its validity, relevance and results.
Clinicians should critically appraise papers using Impact factor (how many times a paper is cited by others)

Question 3

What are the 2 sub types of studies?

Answer 3

Descriptive:
Population - ecological (eco-bank)
Observational - Case control/report, case series and cross sectional (prevalence)

Analytical (statistical analysis)
Observational - case report and cohort (incidence)
Interventional - clinical trials

Question 4

What is prospective vs retrospective?

Answer 4

Prospective
- data collected from start to end of study

Retrospective
- data collected from the past

Question 5

What is the incidence vs prevalence?

Answer 5

Incidence

• rare of occurrence of new cases disease
• no of cases in population at specific time

Prevalence
- how much of a disease there is in a population at particular point of time

Question 6

What is the layout of an academic paper?

Answer 6

Abstract
Intro
Methods and materials 
Results
Discussion and conclusion 
References

Question 7

What are randomised control trials?

Answer 7

Study that looks at the effectiveness of intervention compared with control group using parallel groups meaning less confounding factors

Question 8

What is the hierarchy of evidence?

Answer 8

Clinical practice guidelines
Meta analysis (systematic review with homogeneity then heterogeneity of studies) 
Systematic reviews
Randomised controlled trials 
Cohort studies 
Case control studies
Case report (expert opinions)
Animal and lab studies

Question 9

What is the null hypothesis?

Answer 9

Results that will accept or reject the null hypothesis so if a study is statistically significant the null hypothesis will be rejected

Question 10

What are confidence intervals?

Answer 10

Measure of the true size of effect of a study
95% CL = large CL is better than small CL
If it includes 0 it is not statistically significant.

Question 11

What P values show that results are statistically significant?

Answer 11

<0.05 = statistically significant

<0.005-0.001 = very good statistical significance