Quiz 2 Flashcards
why do we use stats in medicine
identify how common or rare a condition may be
understand how frequent a treatment is used
assess accuracy of a diagnostic test
evaluate how well tx’s work
describe risk factors for a disease
eval how well tx works
eval likelihood that tx will cause side effects
compare costs of diff tx strategies
describe two different types of statistics
descriptive and interential
what are descriptive statistics
they allow us to summarize data so it is easier to intrepret
ex. summarizes performance on an exam
how are descriptive stats commonly represented?
Graphically
Name different types of descriptive stats
means or average medians counts percentages ranges standard deviation
what are inferential statistics
allows researchers to make conclusions about a larger population from a smaller study sample
way of determining how the study results are affected by random error
What is random error
relates to the number of subjects measured. As you increase the number of subjects measured, the amount of random error decreases.
give an example of both descriptive and inferential
56% of polled respondents would vote in favor of the amendment
(plus or minus 5%)
56 is descriptive
plus or minus 5% is inferential
what are terms commonly used in inferential stats?
P-value
Statistical significance
Confidence interval
what are two types of data collected from research?
Continuous or categorical (dichotomous is subtype)
what is categorical data?
limits potential responses to certain categories like:
college major OR Color
What is dichotomous data?
Limits potential responses to two potential responses.
Death (yes/no)
Pregnancy (yes/no)
What is continuous data?
continuous data can take any number within a given range, for example blood pressure, age and pain (0-10)
What types of data are often consistent with averages or means?
continuous data
What are common statistics used to describe center of a data set
Mean or average
median or middle response
What are common statistics used to describe the spread or variabilllity of data?
Range
Innterquartile range
standard deviation
What is the most common way to describe the center of data?
Mean or average
How to calculate the mean of a data set?
Add the values of all observations in the data set
divide the sum by the number of observations
What is the definition of median?
The median represents the exact center point in a data set
How do you calculate the median?
Order all observations from smallest to largest
Choose the middle observation (if there is an even number of observations calculate the mean or average of the two middle values)
when data is symetrical, can mean and median be similar
yes
Median values are not affected by extremes. T/F
True
What is the limitation of the mean?
It is influenced by extreme values and misrepresent data
what are three different types of describing spread and variability?
range
interquartile range
standard deviation
