L10- Clinical Epidemiology, Disease, Therapy, Prognosis

Question 1

define prevalence

Answer 1

number of cases / population

Question 2

define point prevalence

Answer 2

= existing cases at a point in time

useful in determining if an outbreak is occuring

Question 3

define period prevalence

Answer 3

prevalence during specified period, useful in seeing trends

Question 4

define incidence proportion

Answer 4

number of new cases / population w/o disease at start of period

Question 5

define incidence rate (density)

Answer 5

number of new cases / person-time at risk

Question 6

relate prevalence to incidence (mathematically)

Answer 6

P = I * D

D- average duration

Question 7

define EER

Answer 7

(experiment event rate = a / (a+b) )

-rate of event in treatment

Question 8

define CER

Answer 8

(control event rate = c / (c+d) )

-rate of event in control

Question 9

define Hazard ratio and the three possible values

Answer 9

HR = hazard in intervention group / hazard in control group

• HR < 1 –> dec risk of event
• HR = 1 –> no change in risk
• HR > 1 –> inc risk of event