Flashcards in Biostat Deck (43):

1

## what is sensitivity?

### probability that person with disease has a positive test. if negative rule out disease

2

## what is specificity?

### probability that person without disease has a negative test. if positive, rule in disease

3

## RR?

### a/a+b/c/c+d

4

## OR?

### a*d/b*c

5

## what is precision testing and what reduces precision?

### reliability. random variation reduces precision.

6

## what is accuracy testing and what reduces accuracy?

### validity. systematic error (bias) decreases accuracy

7

## increase in precision affects what 2 values?

### increase power, decrease std deviation

8

## odd ratio calculated in what observational study?

### case control (looks at endpoint (disease) and than tries to determine risk factors)

9

## relative risk calculated in what observation study?

### cohort (has a risk factor and looks back to see who developed disease with risk factor)

10

## when does OR=RR?

### when outcome is uncommon in a population

11

## what helps control confounding variables?

### matching such that both groups have similar distribution (eg age, race) in accordance with those variables

12

## biases pose a threat to what of the study?

### validity

13

## methods to decrease confounding bias?

### matching, restriction, randomization

14

## attributable risk?

### a/a+b-c/c+d

15

## relative risk and incidence can only be calculated from what?

### prospective or experimental trials (ex prospective cohort)

16

## what values significant for OR and RR?

### any value besides 1

17

## odds ration can be calculated for what?

### retrospective (ex case control)

18

## another name for prevelance surgery?

### cross-sectional

19

## what is an epidemic?

### observed incidence greatly exceeds expected incidence

20

## define and give an example for nominal, ordinal, and continuous types of data and type of test it is associated with?

###
nominal-no numeric value (eg day of week)

ordinal-ranking but no quantification (eg class rank does not specify how far number 1 is ahead of you)

continuous-numerical measurement

chi squared (nominal or ordinal), t-test or anova (continuous)

21

## define p-value?

### that the data were obtained by random error or chance

22

## what correlates to chance of making type 1 error?

### p-value because it claims that an effect or difference is presence when none really exists. so if p is 4%, there is less than 4% chance making type I error

23

## what is type II error?

### saying there is no difference (null hypothesis accepted) when one actually exists

24

## what is power and how do you increase?

### probability of rejecting null hypothesis when it is actually false. increase sample size

25

## how do you know if you have a confounding variable?

### it affects both the independent (manipulated) and dependent (outcome) variables

26

## what is admission rate bias?

### hospital A and B compared for mortality for MI. A is greater than B, but acutally they have tougher admission criteria and take sicker so they will have greater mortality

27

## what is unacceptability bias?

### ppl do not admit to embarassing behavior, claim to exercise more or claim to take experimental drugs and spit them out

28

## test needed for caustic ingestion?

### generally alkaline. need upper GI endoscopy within 24 hours to access extent of injury

29

## cyanide poisoning management options for dermal, ingested, and all exposure?

###
dermal-remove clothing, skin decontamination

ingestion-activated charcoal

all:

1) hydroxocobalamin 2) sodium thosulfate 3) nitrites followed by thiosulfate if not first two

30

## best initial step vs best tx for organophosphate?

###
best initial step-remove all clothes and washing of skin to prevent more pesticide absorption

best tx-atropine

31

## tx diphenydramine poisoning?

###
anticholingergic/antihistaminic properties (Dry as a bone, red as a beet, blind as a bat, hot as a hare, full as a flask, mad as a hatter,

Physostigmine

32

## tx iron poisoning

### whole bowel irrigation, deforoxamine

33

## best predictor intox for opioid?

### decreased RR

34

## differentiate opioid vs benzo intox?

### degree of resp depression and miosis in opioid (vs normal pupils in benzo)

35

## when do you give activated charcoal for acetaminophen?

### greater than 7.5 g or greater than 150 mg/kg for kid in less than 4 hours ingested

36

## nahco3- antidote for what and what does it help do?

### TCA poisoning and alleviates cardiac toxicity of QRS widening and possible ventricular arrhythmia as Na+ competes for TCA spots increasing gradient across cardiac cells

37

## exertional vs nonexertional heat stroke?

###
exertional-problem with heat dissipation due to thermoregulation failure

nonexertional-underlying impaired thermoregulation due to meds and underlying illness

38

## central scotoma, decreased afferent pupillary reflex, visual blurring, and altered mentation

### methonal ingestion

39

## flank pain, hematuria, oliguria, CN palsy, and tetany

### ethylene glycol

40

## cns depression, disconjugate gaze, and absent ciliary reflex intox?

### isopropyl alcohol ingestion

41

## tx otitis externa

### topical ofloxacin, neomycin, polymyxin B

42

## cause and tx infections myringitis?

### Mycoplasma or S pneumoniae. macrolides

43