Medical Statictics and Epidemiology, as part of the MRCP 1 course. These are slideshows only. The demonstration with video presentation and explanation that goes along with these slides, as well as free example exam questions and the paid full e-lecture can be viewed at https://www.123doc.com/electures/statistics-and-epidemiology/

1. Statistics and epidemiology
For the membership examination
Ian Forde

2. Syllabus
• One variable, one population
• What’s the distribution?
• Normal and skewed distributions
• One variable, two populations
• Is the difference real or due to chance?
• Hypothesis testing, errors and p-value
• Two variables, one population
• Are they correlated?

3. Measure of central tendency
• Mean: Sum of the values divided by their numbers
• Mode: Most frequently occurring value(s)
• Median: the middle value when arranged in order of
size

4. Measure of spread
• Variance: average squared
distance from the mean
• Standard division: Square
root of the variance
= √ Variance
Interquartile range: the middle
50 % of the values when
arranged in order of size
_ 2
Variance = ∑ (x-x)
n
is the standard way of
representing the arithmetic
mean pronounced x bar
∑ is the Greek capital latter
sigma that means total of or sum
of
X is the value of the variable ‘x’
N is the number of the volume
or data points

5. Haemoglobin concentration was measured
in a sample of dialysis patient and gave
following results (g/dL): 8.3, 11.3, 10.4,
12.1, 9.6, 8.3

6. Which of the following statement
is true?

7. Which of the following statement is
true?
The mode can not be calculated for this sample
The Median can not be calculated for this sample
The mean and the median in this sample have the same value
The mode and the median in this sample have the same value
If the sample were normally distributed we would expect the mode, the median
and the mean to have different value

8. Epidemiology and Clinical trials
Ian Forde

9. Syllabus
• Study Design
• Accuracy, reliability and precision
• Sensitivity and specificity
• Risk
• Prevention
• Bias
• Intention to treat analyses

10. Exposure Outcome
COHORT STUDIES
• Prospective
• Best of rare exposure, common
outcome
• Allow us to look at many
outcomes simultaneously
CASE CONTROL STUDIES
• Retrospective
• Best of rare outcome, common
exposure
• Allow us to look at many exposure
simultaneously
• Susceptible to bias

11. Which would be the study designs
would best be suited for the
situation described below?

12. Which would be the study designs would best
be suited for the situation described below?
A. A case control study to look at the relationship between brain tumors
and mobile phone use
B. A case control study to look at the relationship between skin cancer and
space flight
C. A cohort study to look at the relationship between pure red cell aplasia
and air travel
D. A randomized control trail to look at the relationship between melanoma
and sun block use
E. A randomized control trail to look at the relationship between childhood
television watching and amblyopia