Statistics Flashcards
1
Q
Parametric tests:
Require data to have normal distribution
A
True
2
Q
Parametric tests:
Give the results as odds ratios
A
False
3
Q
Parametric tests:
Are appropriate for comparing the incidence of hypotension in two groups
A
False
4
Q
Parametric tests:
Are less powerful than non-parametric ones
A
False
5
Q
Parametric tests:
Include analysis of varience
A
True
6
Q
95% confidence intervals:
Indicate the range of plausible values for the true result
A
True
7
Q
95% confidence intervals:
become wider, the larger the sample size
A
False
8
Q
95% confidence intervals:
Can be used to describe a difference between two groups
A
True
9
Q
95% confidence intervals:
Can be used to indicate the incidence of a rare complication
A
True
10
Q
95% confidence intervals:
Indicate whether a difference is statistically significant
A
True
11
Q
The ASA physical status of a group of patients:
Is best described by median and standard deviation
A
True
12
Q
The ASA physical status of a group of patients:
Is an example of ordinal data
A
True
13
Q
The ASA physical status of a group of patients:
Is usually normally distributed
A
False
14
Q
The ASA physical status of a group of patients:
Can be plotted as a bar chart
A
True
15
Q
The ASA physical status of a group of patients:
May be compared using the chi-squared test
A
True
16
Q
Standard deviation:
Is always less than 1
A
False
17
Q
Standard deviation:
Indicates the scatter of data around the central tendency
A
True
18
Q
Standard deviation:
Is the square root of varience
A
True
19
Q
Standard deviation:
Increases as sample size increases
A
False
20
Q
Standard deviation:
Is interchangeable with standard error
A
False
21
Q
Continuous data:
Are always symmetrical when plotted
A
False
22
Q
Continuous data:
May be transformed using logarithms
A
True
23
Q
Continuous data:
Are compared using T-tests
A
True
24
Q
Continuous data:
Can include negative numbers
A
True
25
Continuous data:
| Can also be called categorical data
False
26
if p = 0.05 for a comparison of two treatments:
| There is a 95% chance that there is no difference between the treatments
False
27
if p = 0.05 for a comparison of two treatments:
| The null hypothesis is incorrect
False
28
if p = 0.05 for a comparison of two treatments:
| The chance of a false negative is 5%
False
29
if p = 0.05 for a comparison of two treatments:
| We can conclude that one treatment is more effective
False
30
if p = 0.05 for a comparison of two treatments:
| The data we have observed would only occur 5% of the time or less if the treatments were equally effective
True
31
The interquartile range is:
| The variance between four groups
False
32
The interquartile range is:
| The middle 50% of the data
True
33
The interquartile range is:
| The same as standard deviation
False
34
The interquartile range is:
| Often represented by the box in a box-whisker plot
True
35
The interquartile range is:
| Often represented by the tails of a normal distribution curve
False
36
In a clinical trial:
| Blinding reduces the effects of the confounding factors
False
37
In a clinical trial:
| A placebo is usually considered unethical nowadays
False
38
In a clinical trial:
| Controls may be standard treatment, placebo or historical
True
39
In a clinical trial:
| Randomisation is always required
False
40
In a clinical trial:
| Intention to treat is always required
False
41
In a study comparing two airway devices, the incidence of sore throat is 20% with the standard device and 15% with the new device. Which of the following are true:
The relative risk reduction is 5%
False
42
In a study comparing two airway devices, the incidence of sore throat is 20% with the standard device and 15% with the new device. Which of the following are true:
The absolute risk reduction is 5%
True
43
In a study comparing two airway devices, the incidence of sore throat is 20% with the standard device and 15% with the new device. Which of the following are true:
The p value is 5%
False
44
In a study comparing two airway devices, the incidence of sore throat is 20% with the standard device and 15% with the new device. Which of the following are true:
The odds ratio is 5%
False
45
In a study comparing two airway devices, the incidence of sore throat is 20% with the standard device and 15% with the new device. Which of the following are true:
The number needed to treat is 5
False
46
The power of a study:
| Depends on the statistical test used to compare the data
True
47
The power of a study:
| Is the ability to detect a significant difference between the groups
True
48
The power of a study:
| Only applies to parametric tests
False
49
The power of a study:
| Equals 1-? where ? is the type II error
True
50
The power of a study:
| May be calculated before or after a study
True
51
Randomisation:
| Always results in equal groups
False
52
Randomisation:
| Should always be tested by comparing the groups baseline data
False
53
Randomisation:
| Requires a power analysis to be valid
False
54
Randomisation:
| Increases the likelihood that any significant difference is due to the treatment being studied
True
55
Randomisation:
| Helps preserve blinding
True
56
Comparing two sets of urine output volumes:
| A t-test is appropriate unless the data are normally distributed
False
57
Comparing two sets of urine output volumes:
| The comparison should always be paired
False
58
Comparing two sets of urine output volumes:
| The results may be expressed as a 95% confidence interval
True
59
Comparing two sets of urine output volumes:
| The standard deviations should be similar in order to do a statistical comparison
False
60
Comparing two sets of urine output volumes:
| Can be done using parametric tests
True
61
The following measures of central tendency could correctly describe the matched type of data:
Variance and normally distributed data
False
62
The following measures of central tendency could correctly describe the matched type of data:
The standard error of the mean and normally distributed data
False
63
The following measures of central tendency could correctly describe the matched type of data:
Mode and positively skewed data
False
64
The following measures of central tendency could correctly describe the matched type of data:
Median and negatively skewed data
True
65
The following measures of central tendency could correctly describe the matched type of data:
Mode and categorical data
True
66
Regarding correlation coefficient:
| A positive value implies that a rise in one variable causes a rise in the other
False
67
Regarding correlation coefficient:
| Can be calculated for parametric and non-parametric data
True
68
Regarding correlation coefficient:
| Is measured on a scale of -1 to1
True
69
Regarding correlation coefficient:
| Is usually denoted by the symbol r
True
70
Regarding correlation coefficient:
| A value of -1 indicates perfect positive correlation
False
71
The following are non-parametric tests:
| Chi-squared test
True
72
The following are non-parametric tests:
| ANOVA
False
73
The following are non-parametric tests:
| The mann-whitney test
True
74
The following are non-parametric tests:
| The students T-test
False
75
The following are non-parametric tests:
| The wilcoxon signed rank sum test
True
76
An odds ratio is the probability of a given outcome, divided by the probability of the alternative outcome
False
77
Odds ratios and risk ratios are both valid measures of association
True
78
Risk ratios can be affected by the incidence of the disease we are studying
True
79
A risk ratio can be defined as the risk of a certain outcome given certain conditions, divided by the risk of that outcome given other conditions
True
80
Risk ratios are more intuitive than odds ratios
True
81
Statistical definitions:
| Variance is the sum of the differences divided by the degrees of freedom
True
82
Statistical definitions:
| A normal distribution is one where the mean, median and mode are the same
True
83
Statistical definitions:
| Mode is the most frequently occurring variable
True
84
Standard error of the mean is the square root of the variance
False
85
Standard deviation is the standard error of the mean divided by the square root of the number observed
False
86
Concerning errors in statistics:
| The power of a study will be greater if you are trying to detect a small difference
False
87
Concerning errors in statistics:
| A type 1 error is a false negative
False
88
Concerning errors in statistics:
| A type 1 error is the same as the beta error
False
89
Concerning errors in statistics:
| The power of a study describes the likelihood of detecting a real difference if it exists
True
90
Concerning errors in statistics:
| A type 1 error is unlikely to influence the conclusions of a trial
False
91
The following are parametric tests:
| Spearman's rank correlation
False
92
The following are parametric tests:
| Fishers exact test
False
93
The following are parametric tests:
| ANOVA
True
94
The following are parametric tests:
| Kruskal-Wallis
False
95
The following are parametric tests:
| Forest plots
False
96
The Chi-squared test:
| Can be used to test nominal data
True
97
The Chi-squared test:
| Requires the standard error of the mean to be calculated
False
98
The Chi-squared test:
| Does not requires a knowledge of the number of degrees of freedom
False
99
The Chi-squared test:
| Should not be used for data with small groups
True
100
The Chi-squared test:
| Can be used to compare more than 2 groups
True
