2. Clinical Epidemiology Intro & Abnormality

Question 1

In a right modal set of data which is true?

A. Median> Mode
B. Median>Mean
C.Mean> Mode
D. Mode=Median

RFA

Answer 1

Ans. B Median> mode

Question 2

In a left skewed set of date which is true?

A. Mode>Median
B. Median>Mode
C. Mean>Mode
D. Mean> Median

RFA

Answer 2

Ans. A Mode> Median

Same as my other question just changed Right modal for left Skewed

Question 3

In a study which assigns a different number to Caucasians, African Americans, Native Americans, and Asian individuals the data can be classified as:

A. Quantitative
B. Nominal
C. Ordinal
D. Open
E. Continuous Variable

SZ

Answer 3

Ans. B Nominal

In nominal data order does not matter. Characteristics are given a nominal value.

Question 4

An example of ‘Discrete’ data for a given patient would be?

A. Stage II Breast Cancer
B. 126 BG
C. Sex: Female
D. Race: African American
E. Number of Children: 5 

SZ

Answer 4

Ans. E. Number of children: 5

Discrete date is a whole integer.

A. Stage II Breast Cancer = Ordinal
B. 126 BG = Continuous
C. Sex: Female = Binary
D. Race: African American = Nominal

Question 5

A dataset of BMI of a population is negatively skewed. This means that most people in the population have a _____ BMI (MG)

A. Higher
B. Lower
C. Normal

Answer 5

A. Higher

Negative skew means the tail is to the left. So most values are to the right (higher x axis value).

Question 6

A dataset of BMI of a population is negatively skewed. This means that most people’s BMIs are _____ than the mean for the dataset. (MG)

A. Higher
B. Lower
C. The mean is equal to what most people have as their BMI

Answer 6

A. Higher

In a negative skew, the mean is pulled down by the outliers in the tail. This makes the mean lower than where the peak of the distribution lies. The median and mode are both higher than the mean in a negative skew.

Question 7

In order to be considered normal a value must be within how many standard deviations of the mode?

MM

Answer 7

1 standard deviation which is also 68%

Question 8

A highly reproducible test has (high/low) ______ but if the measurement does not represent what it is supposed to the test has (high/low) _______?

Choose high/low and fill in the blank

MM

Answer 8

High Precision

Low Accuracy

Question 9

A Bimodal Distribution, one with two or more central clusters, suggests ________.

FA

Answer 9

Two Different Populations

Examples:
Male/female height
Kaposi’s sarcoma (Young men with AIDS, Older men without Aids)
Hodgkin Lymphoma Age of onset

Question 10

In a positively or negatively skewed data set, the best measure of dispersion is?

A. Range
B. Variance
C. Interquartile Range
D. Standard Deviation

Answer 10

C. Interquartile Range

Standard deviation and Variance are both preferred in data sets that are normally distributed. IQR is robust and not effected by outliers as much.