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

35

## 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