Statistics in medicine Flashcards
Define sensitivity, and give the formula to calculate this
The proportion of people with the disease who test positive
Define specificity
The proportion of people without the disease who test negative
Define positive predictive value
The chance that people have the disease if they test positive
Give the formula to define positive predictive value
a/a+b
Define negative predictive value
The chance that people don’t have the disease if they test -ve
Give the formula for negative predictive value
d/c+d
Give the formula for calculating sensitivity
a/a+c
,Give the formula to calculate specificity
d/d+b
Does the positive predictive value increase when the prevalence in a population is high or low?
High
Does the negative predictive value increase when the prevalence in a population is high or low?
Low
How many levels of evidence are there?
5
What is Level 1, with regard to levels of evidence?
Systematic reviews, RTCs
What is Level 2, with regard to levels of evidence?
Cohort studies
What is Level 3, with regard to levels of evidence?
Case-controlled studies
What is Level 4, with regard to levels of evidence?
Case series
