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Flashcards in EBM Deck (50):
1

Systematic revue

overview of particular clinical research question

2

Meta-analysis (3 points)

Uses statistical method to summarise studies, often included in a systematic review, produces single quantitative result

3

Single quantitative result

pooled treatment result / overall effect estimate

4

Forest plot

graphical result of meta-analysis

5

Point effect estimate (forest plot)

vertical midpoint of each square, mean treatment effect for that study

6

forest plot vertical line

line of no effect

7

horizontal line (each) on forest plot

confidence interval

8

if horizontal line (confidence interval) crosses vertical line (line of no effect) then..

No significant difference between two treatments

9

width of diamond at bottom of forest plot

certainty of overall affect estimate - 95% confidence interval

10

confidence interval

range of values within which the true mean of whole population is expected to lie

11

95% confidence interval

95% confident that true mean lies somewhere between two limits of interval

12

larger sample sizes lead to CIs which are

narrower

13

less variability leads to CIs which are

narrower

14

a larger confidence level results in CIs which are

broader

15

outcome variable

dependent variable

16

outcome variable of meta analysis

often odds ratio (NOT ALWAYS)

17

in a meta analysis where the mean difference is zero

no difference between groups

18

negative mean difference in meta analysis

favours treatment

19

positive mean difference in meta analysis

favours control (treatment harmful compared to no treatment)

20

relative frequency

percentage of total number in sample

21

categorical variable

non-numerical

22

numerical variable

numerical value, measurable quantity. Continuous or discrete

23

continuous numerical variable

measurement on continuous scale e.g. height

24

discrete numerical variable

numbers of events, limited number of possible values e.g. pregnancies, heart attacks

25

3 graphical representations of categorical variables

frequency distributions, pie charts, bar charts

26

4 graphical representations of numerical variables

frequency distributions, histograms, frequency polygons, quantiles

27

measures of central tendency (3)

mean, median, mode

28

measures of spread of data (3)

range, interquartile range, standard deviation

29

purpose of shapiro-wilk test

determining normality (or otherwise) of distribution

30

purpose of t-test

determine whether 2 means differ reliably

31

correlation and linear regression purpose

testing for relationship between 2 variables

32

null hypothesis of hypothesis testing

no effect

33

p < 0.05 hypothesis testing

reject null hypothesis - statistically significant result

34

shapiro wilk null hypothesis

sample from normally distributed population

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shapiro wilk p <0.05

reject null hypothesis - statistically significant result, sample unlikely to be from normal distribution

36

3 types of t test

one sample t test, unpaired t test, paired t test

37

t test null hypothesis

no difference between 2 means

38

t test p <0.05

reject null hypothesis- statistically significant result, reliable difference between 2 means

39

pearson's r between which two values

-1 and +1

40

r = 0 (approx)

no relationship between variables

41

pearson's r p < 0.05

reject null hypothesis - statistically significant result, reliable relationship between two variables

42

pearson's r null hypothesis

no relationship between two variables

43

what is p value

probability of observing the results of a trial if the null hypothesis is true

44

shapiro wilk test statistic

W

45

one sample t test used to

compare sample mean with population mean

46

unpaired t test used to

test whether there is difference between 2 independent groups - comparing same measure in 2 different groups

47

paired t test used to

compare dependent samples of groups e.g. one subject at two times

48

t test test statistic

t

49

pearson's r is a

correlation coefficient

50

cochrane review =

systematic reviews of primary research in human health care and health policy. highest standard of evidence-based heath care