Module 5

Question 1

what are hazard ratios

Answer 1

a measure of how often an event occurs in one group compared to how often it happens in another group over time. Summarizes and analyzes time to event data.

Question 2

what are survival curves

Answer 2

curve that starts at 100% of the sample population that shows the percentage of the population still surviving.

Question 3

calculate survival probability

Answer 3

number of patients who have not experienced event divided by number of patients who are at risk

Question 4

HR =1

Answer 4

no difference in survival rates b/w compared groups

Question 5

HR>1 or <1

Answer 5

survival is better in one of the compared groups

Question 6

HR = 0.5

Answer 6

prognostic factor or intervention will cause Pt to progress more slowly than the compared group

Question 7

if confidence interval crosses 1, then…

Answer 7

there is no statistically significant difference b/w the groups

Question 8

ways to express prognostic results (3)

Answer 8

absolute terms (5 yr survival rate)
relative terms (risk from prognostic factor)
survival curves (time to event)