Flashcards in Critical appraisal Deck (22)

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1

## Confounder

### variable associated with both exposure and outcome

2

## Best type of study design to minimize effects of confounders

### RCT

3

## Cons of doing RCT

### Expensive, time consuming, difficult for rare events

4

## how to calculate relative risk

### incidence of intervention / incidence of control

5

## Relative risk reduction

###
ARR = (risk in intervention - risk in control)

divided by

risk in control group

(or 1-RR)

6

## case control studies

### identify groups based on a specific OUTCOME, see if they have certain exposures

7

## cohort studies

### follow subjects with a specific EXPOSURE and evaluate outcomes, exposure not under investigator's control

8

## best method to study rare diseases

### case control (go back and look at their history)

9

## sensitivity

### given that the disease is present, the probability that the test is positive

10

## specificity

### given that the disease is absent, the probability that the test is negative

11

## sensitivity (equation)

### TP/(TP+FN)

12

## specificity (equation)

### TN/(TN+FP)

13

## positive predictive value

### given that the test is positive, the probability that the disease is present

14

## negative predictive value

### given that the test is negative, the probability that the disease is absent

15

## PPV and NPV vary with...

### disease prevalence

16

## PPV (equation)

### TP/(TP+FP)

17

## NPV (equation)

### TN/(TN+FN)

18

## Power of a study (equation)

### 1 - Type II error (the chance that the p value will not be statistically significant despite a true difference between the two groups)

19

## Type 1 error

### the probability that the difference observed is due to chance

20

## p-value (definition)

### the probability that the difference observed in the study is simply due to chance (type 1 error)

21

##
LR for a positive test

### sensitivity/(1-specificity)

22