Fiser Chapter 44 STATISTICS Flashcards Preview

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Flashcards in Fiser Chapter 44 STATISTICS Deck (34):
1

Meta-analysis

combines data from different studies

2

RCTs avoid ____

avoids treatment biases

3

Promoting culture of safety

Confidential system of reporting errors
Emphasis on learning over accountability
Flexibility in adapting to new situations or problems

4

Case-control study

Those who have disease are compared with those who do not

Compare frequency of suspected risk factor

Retrospective

5

Paired t tests

Before and after studies (weight before and after, drug versus placebo)

Quantitative

6

p

null hypothesis rejected

>95% likelihood that the difference between the populations is true

AKA

7

Parameter

population

8

Kaplan-Meyer

estimates survival in small groups

9

NPV

TN / (TN + FN)

10

Relative risk

incidence in exposed / incidence in unexposed

11

Variance

spread of data around a mean

12

Sensitivity

TP / (TP + FN)

13

Student's t test

Compares means between 2 independent groups

Quantitative

14

Accuracy

???

15

Sentinel event

Unexpected occurrence involving death or serious injury, or risk thereof

Hospital undergoes root-cause analysis to prevent and minimize future occurrences

eg wrong site surgery

16

Risk factors for retain object

Emergency procedure
Unplanned change in procedure
Obesity
Towel used for closure

17

Chi-squared test

Compares 2 groups with categorical variables

e.g. number of obese patients with and without diabetes versus number of nonobese patients with and without diabetes

18

GAP protection technique

gaps in care (eg change in caregiver, divisions of labor, shift changes, transfers) can lead to loss of information and error

Prevention: structured handoffs and checklists (face to face if possible); standardizing orders; reading back orders if verbal

19

Type 1 error

no difference (but thinks there is)

20

Mean

average

21

Incidence

Number of new cases diagnosed over a certain time frame in a population

22

Specificity

TN / (TN + FP)

23

Mode

most frequently occurring value

24

Median

middle value (50th %ile)

25

Cohort studies

compare disease rate between exposed and unexposed groups

Nonrandom

Prospective

26

ANOVA

Compares means between more than 2 groups

Quantitative

27

Power of test

Probability of making correct conclusion

1 - probability of type 2 error
1 - probability of not seeing difference when there is one

Likelihood that conclusion is true
Larger sample size increases power

28

Nonparametric statistics

compares categorical (qualitative variables)

E.g. race, sex, medical problems, medications

29

Predictive values depend on ___

disease prevalence

30

Type 2 error

there's a difference (but don't see it)

due to small sample size

31

Prevalence

number of people with disease in a population

higher in chronic diseases

32

Double-blind controlled trial avoids ____

avoids observational biases

33

PPV

TP / (TP + FP)

34

JCAHO prevention of wrong site/procedure/patient protocol

Time out before incision
Pre-op verification of patient and procedure
Operative site and side
Availability of implants or special requirements