Descriptive & Inferential Statistics

Question 1

Why are statistics important in healthcare?

Answer 1

Providers, policy makers, and patients use statistics to make decisions and communicate with others

Question 2

Give examples of how statistics are used in healthcare.

Answer 2

Assessing the accuracy of a diagnostic test and if it is worth performing
Describing the natural history or prognosis of a disease
Describing risk factors for a disease
Evaluating how well different treatments work

Question 3

What is the purpose of descriptive statistics?

Answer 3

To describe and summarize data for easier interpretation

Question 4

What is the purpose of inferential statistics?

Answer 4

They allow researchers to make conclusions about a larger population from a smaller “study sample.” They are a way of determining how the study results are affected by random error.

Question 5

Within descriptive statistics how to categorial and continuous data compare?

Answer 5

Categorical data limits potential responses to certain categories, like college major or color

Continuous data can take any number within a given range

Question 6

What are statistical measures of central tendencies? What do they measure?

Answer 6

mean, median, mode

Measures the “average” or “typical” response of a study.

Question 7

What are statistical measures of spread? What do they measure?

Answer 7

Range, Interquartile range, Standard deviation

Measures how variable outcomes of a study were.

Question 8

A small interquartile range means most of the data fell close to the ______

Answer 8

most of the data fell close to the median

Question 9

To find the interquartile range ______

Answer 9

Find the median
Divide the data below and above the median each in half
The values at the 25% and 75% quartiles represent the interquartile range

Question 10

The standard deviation examines _________

Answer 10

how far the data are spread out from the mean

Question 11

P-value assesses ___________

Answer 11

the probability that the results of a study are due to chance, the statistical significance of a difference between two compared variables

Question 12

Define null hypothesis

Answer 12

A hypothesis which rejects/doubts an experimental hypothesis

Question 13

How does one determine if the null hypothesis was assumed in a study?

Answer 13

If p-values were presented in a table of data

Question 14

Median and mode may be better indicators of center than mean when _________

Answer 14

there are extreme values in the data range

Question 15

P-value is a measure of _______

Answer 15

type I error

Question 16

Define type I error

Answer 16

Null Hypothesis is rejected even though it is true

Question 17

What factors influence P-value?

Answer 17

magnitude of effect, sample size, variability of test subjects

Question 18

If variability increases, p-value will ______

Answer 18

increase

Question 19

In studies about treatment, statistical power is _________

Answer 19

the ability of a study to detect a statistically significant result, if one really exists

Question 20

A power of ____ or more is commonly used in healthcare research. This means that a study has an ____ chance of __________

Answer 20

0.80

80%

finding a statistically significant result if one really exists

Question 21

Describe how to calculate relative risk

Answer 21

(probability of event occurring in exposed group) / (probability of event occurring in non-exposed group)

Question 22

Confidence interval is ________

Answer 22

the interval that encompasses the true value for a given confidence level

Question 23

A narrow confidence interval indicates ______

Answer 23

precision / well-powered study