Flashcards in Behaviorial Science/Biostats Deck (36):

1

## power of a study increases w/

### increased sample size, expected effect size, precision management

2

## power =

###
1 - beta

beta = stating there ISN'T an effect/difference when ONE EXISTS

3

## sensitivity =

###
test detects dz when dz present; screening test (rule out a dz)

1 - FN rate

TP/(TP + FN) aka TP/total dz +

a/(a+c)

4

## specificity =

###
test indicates NO DZ when dz actually absent; confirmatory test (rule in a dz)

1 - FP rate

TN/(TN+FP) aka TN/total dz negatives

d/(b+d)

5

## PPV

###
person WITH dz tested positive in test

TRUE POSITIVE!!

TP/(TP+FP)

a/(a+b)

high pretest probability = high PPV

6

## NPV

###
person WITHOUT dz who tested negative in test

TRUE NEGATIVE!!

TN/(FN+TN)

d/(c+d)

high pretest probability = LOW NPV

7

## incidence

### # of new cases

8

## prevalence

###
incidence x time

looks at ALL current cases --> tx that prolongs survival INCREASES prevalence

9

## odds ratio (OR)

###
used in case-control studies

odds that group w/ dz exposed to risk factor divided by odds that group w/o dz exposed to risk factor = (a/c)/(b/d) =

ad/bc

10

## relative risk (RR)

###
used in cohort studies

risk of developing dz in exposed group divided by risk in unexposed group

[a/(a+b)]/[c/(c+d)]

if low prevalence --> RR = OR

11

## attributable risk

###
difference in risk b/w exposed/unexposed groups

Attributable Risk % = (RR - 1)/RR

[a/(a+b)] - [c/(c+d)]

event rate(of tx) - event rate(in other group)

12

## Absolute risk reduction (ARR)

###
AR(in control) - AR(w/ tx)

[c/(c+d)] - [a/(a+b)]

13

## # needed to treat

###
# pts needed to treat for 1 pt to benefit

1/ARR

14

## # needed to harm

###
# of pts who need to be exposed to RF for 1 pt to be harmed

1/attributable risk

15

## relative risk reduction (RRR)

### [AR(control) - AR(tx)]/AR(control)

16

## type 1 error (alpha)

###
stating there IS an effect when there ACTUALLY IS NOT (mistakenly reject null hypothesis)

b/(b+d)

17

## type II error (beta)

###
stating there IS NOT an effect when there ACTUALLY IS (fail to reject null hypothesis)

c/(a+c)

18

## 95% confidence interval Z-score =

### 1.96

19

## 99% confidence interval Z-score =

### 2.58

20

## standard error of mean (SEM) =

###
SD/(sq rt of n)

SD (standard deviation) = aka sigma

n = sample size

21

## formula to obtain confidence limits

### mean +/- [Z-score x SEM]

22

## wave seen in awake stage?

### beta (highest freq, lowest amp)

23

## wave seen in relaxation stage?

### alpha

24

## wave seen in N1 stage?

### theta

25

## wave seen in N2 stage?

### sleep spindles and K complexes

26

## wave seen in N3 stage?

### delta (lowest freqm highest amp)

27

## wave seen in REM?

### beta

28

## what stage of sleep does night terrors, bedwetting, sleep walking occur

### N3 - NO memory of sleep terror (as opposed to REM)

29

## REM occurs due to what part of brain

### PPRF (paramedian pontine reticular formation)

30

## REM stage ass w/?

###
dreaming

loss of motor tone

erections

increased brain O2 use

31

## sleep stage w/ bruxism (teeth grinding)

### N2

32

## sleep enuresis preferred tx

###
DDVAP (oral desmopressin acetate)

preferred over imipramine, indomethacin

33

## key NT changes in REM sleep

###
increased ACh

NE reduces REM sleep

34

## primary sleep stage in narcolepsy

### straight to REM sleep

35

## tx for narcolepsy

###
modafinil, amphetamines (stimulants)

sodium oxybate (GHB) - for nighttime

36