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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

Describe rinne and weber?

Weber-conductive test where put in center of head. in conductive hearing loss, sound localized to affected ear. in sensorineural hearing loss, sound localized to unaffected ear.
Rinne-compares air with bone and placed on mastoid until no longer than removed to auditory meatus. in conductive hearing loss (bone greater than air) so cannot hear near meatus. in sensorineural, both air and bone conduction decrease so they can hear both