5 - Epidemiology III

Question 1

Define prevalence.

Answer 1

• number of disease cases in a population at a given time
• number of cases / total population
• good for studying chronic disease

Question 2

Define incidence.

Answer 2

• number of new disease cases developing within a certain time frame
• number of new cases within time period / total population at risk
• good for studying infective disease or cancer
• describe as cases/per annum

Question 3

What are the ideal properties of an index? (9)

Answer 3

• clear, unambiguous, objective (not subjective)
• correspond with clinically important stages of disease
• indicate treatment need
• within ability of examiners
• reproducible
• not time-consuming
• acceptable to patient
• amenable to statistical analysis
• allow comparison from other studies

Question 4

What is DMFT?

Answer 4

• decayed, missing and filled teeth (0-32)
• index of caries

Question 5

What is DMFS?

Answer 5

• decayed, missing and filled surfaces (0-148)
• 3-3 have 4 surfaces
• 4-8 have 5 surfaces

Question 6

What is dmf/def index?

Answer 6

• decayed, missing/extracted, filled teeth
• at age 6, scoring teeth c,d,e

Question 7

What is D3MFT?

Answer 7

Obvious decay into dentine

Question 8

What is D1MFT?

Answer 8

Decay into enamel

Question 9

What are the limitations of the DMF/dmf index?

Answer 9

• teeth extracted for reasons other than caries
• influenced by access (inter proximal)
• FS vs restoration?
• past disease activity
• does not detect root caries

Question 10

D/DMF

Answer 10

Indications of treatment need

Question 11

F/DMF

Answer 11

Indication of treatment provision (care index)

Question 12

M/DMF

Answer 12

Indication of treatment failure (ie tooth lost due to caries)