Statistics

Question 1

What is a confidence interval?

Answer 1

Range within which the true effect size is likely to lie within

95% CI is 2 SE around the mean

Narrow CI = good

Question 2

What is a pvalue

Answer 2

Probability result was due to chance

Question 3

What is a hazard ratio?

Answer 3

Prob of an event in comparison to the gold standard following adjustment

HR < 1 - less risk of event
HR =1 - no difference
HR > 1 - more risk of event
HR =4 - four times the hazard

Question 4

Why present CI instead of just p value

Answer 4

allows greater interpretation
Gives an idea of the treatment effect which p value doesn’t
Relates to sample size

Question 5

is a narrow or wide CI better?

Answer 5

narrow as there’s more certainty it represents the treatment effect

Question 6

What is a hypothesis?

Question 7

What are the characteristics of a normal distribution?

Question 8

What is sensitivity and specificity?

Question 9

What is a Kaplan Meier curve?

Question 10

How is data presented in the NJR?