Biostats/Epi Week 3 Flashcards
You are developing a new screen for heart disease which is found to correlate (r=0.7) with the “gold standard” blood test for cardiac enzymes. This is an indication of:
convergent validity
Variable
Anything that can take on a different quality or quantity.
Data distribution
listing of values associated with a particular variable in a collection of data
Frequency distribution
table or graph that indicates how many times a value appears in a data set.
Nominal level of measurement
simplest level of measurement; based on categories that are mutually exclusive and collectively exhaustive.
Ordinal level of measurement
level of measurement that presumes order (i.e. greater than, less than).
Interval level of measurement
measurement based on a scale of equal intervals (a.k.a. ratio level of measurement)
Population (or universe)
all possible criteria cases; complete total cases possible
Sample
Portion of the population collected; from the sample conclusions are drawn about the population
Parameter
characteristic of a population
Statistic
characteristic of a sample
Descriptive Statistics
used to summarize or describe data distributions
Inferential Statistics
used to make statements about a population
You are studying a new screening test. There are 40 people who do not have a disease and 20 test negative for the disease with your new screen. Your new screen’s specificity is:
50%
Your sample is normally distributed with a mean age of 57. The standard deviation in this sample is 5 years. The 2000 census shows your sample is older than a randomly selected national sample. You would expect 68% of your subjects to be:
Between the ages of 52 and 62
Your results are 2,4,6,7,10,12. Your median is:
7
The population in your state is 20% African American, 23% Latino, 17% Asian, and 40% other. A representative sample should include:
23% individuals from Latino populations
You are studying a new screening test. There are 100 people who do not have a disease and 90 test negative for the disease with your new screen. There are 100 people who do have the disease and 80 test positive with your screen. The sensitivity of your screen is:
80%
A study of 30 men was completed and ten watched three hours of television a day, ten watched two hours of television a day, three watched one hour of television a day and seven did not watch television. What was the cumulative percentage of men who watched less than two hours of television a day?
33%
A neurology intern measures how many times per minute a specific brain wave cycles when a person is exposed to a heat source. She is measuring the brain wave response at what level of measurement?
Interval/ratio
You administer your survey regarding eating habits of nurses to all the nurses who are in the cafeteria at lunchtime on a particular day. This is an example of what type of sample?
Convenience sampling
You are looking for participants for a study for a new HIV vaccine. Participants must be 24-32 years old and newly sexually active. These are examples of:
Inclusion criteria
Quantitative Data: Discrete
Deals with integers (number of objects or people)
Quantitative Data: Continuous
Deals with a range (speed, weight, time); has meaning between integers
Qualitative Data
Says something about the sample that cannot be counted
