Measures of disease occurrence

Question 1

INCIDENCE

Answer 1

new cases / cases at risk

Question 2

PREVALENCE

Answer 2

+ of cases / total population at a given point in time

Question 3

How does increase in mortality or quick convalescence of disease impact incidence of prevalence?

Answer 3

Increase incidence
Decrease prevalence

Question 4

Improved quality of care impacts prevalence how?

Answer 4

Increases prevalence

Question 5

Primary prevention impacts incidence how?

Answer 5

Decreases incidence

Question 6

CRUDE MORTALITY RATE

Answer 6

number of deaths / total population

Question 7

CAUSE SPECIFIC MORTALITY

Answer 7

number of specific deaths / total population

Question 8

CASE FATALITY RATE

Answer 8

number of deaths from a specific disease / number of people affected by the disease

Question 9

STANDARDIZED MORTALITY RATE

Answer 9

observed number of deaths / expected number of deaths

Question 10

ATTACK RATE

Answer 10

number of patients with the disease / population at risk

Question 11

MATERNAL MORTALITY RATE

Answer 11

number of maternal deaths / number of live births

Question 12

CRUDE BIRTH RATE

Answer 12

number of births / total population size

Question 13

RELATIVE RISK

Answer 13

(diseased/total exposed) / (diseased/total non-exposed)

Question 14

ODDS RATIO

Answer 14

(A/C)/(B/D)

(disease exposure / disease non-exposure) / (no disease exposure / no disease non-exposure)

Question 15

ATTRIBUTABLE RISK

Answer 15

Risk difference

AR = (number of diseased / total pop’n in subgroup 1) 2 (number of diseased / total pop’n in subgroup 2

Question 16

ATTRIBUTABLE RISK PERCENT

Answer 16

AR% = AR / (number of diseased / total pop’n in subgroup 1)

Question 17

POPULATION ATTRIBUTABLE RISK PERCENT

Answer 17

[(overall number of diseased / total population) - (number of diseased / total pop’n in subgroup 2)] / (overall number of diseased / total population)