Homework 1
Q: Who identified the cause of a cholera outbreak as contaminated water from the Broad Street pump?
A: John Snow
Q: Is the spot map of London and cholera an example of descriptive or analytic epidemiology? Why?
A: Descriptive epidemiology, because it visually represents cases without testing hypotheses.
Q: What was Edward Jenner’s contribution to science/epidemiology?
A: He developed the first successful smallpox vaccine by using material from cowpox lesions.
Q: What is the most specific name of a figure showing the number of incident Zika cases by day?
A: Epidemic curve
Q: What did the author predict would eventually happen with COVID-19?
A: COVID-19 would likely become endemic, persisting but at lower, manageable levels.
Q: Define 'Endemic' and provide three examples of endemic diseases in the U.S.
A: Endemic refers to a disease regularly found in a particular area. Examples: Influenza, Lyme disease, and Chickenpox.
Q: Who isolated the bacteria causing anthrax and developed four postulates for disease causation?
A: Robert Koch
Q: Define 'epidemiologic transition'.
A: A shift from mostly communicable to mostly chronic diseases in a population.
Q: Define 'demographic transition'.
A: A shift from high birth and death rates to low birth and death rates.
Q: What is the primary advantage of using toenail clippings vs. blood for assessing lead exposure?
A: Toenail clippings provide a longer-term measure of lead exposure compared to blood.
Q: Which way of measuring lead exposure (toenails vs blood) was more strongly associated with children’s cognitive performance?
A: Blood levels were more strongly associated with cognitive performance.
Q: Why might blood be a more accurate biomarker of lead exposure than toenails?
A: Blood reflects recent exposure and is more directly linked to physiological effects.
Q: What is the official term for a table presenting oral cancer cases and alcohol intake?
A: Contingency table
Q: What is the official term for a figure showing frequency distribution?
A: Histogram
Q: In a standard normal distribution, what percentage of data falls within 1 SD of the mean?
A: Approximately 68%
Q: In a skewed distribution, which direction is the skew if the tail is on the right?
A: Right skewed
Q: A doctor asks, 'How bad do you feel on a scale from 1 to 10?' What type of variable is this?
A: Ordinal variable
Q: A psychotherapist asks, 'How do you feel?' with multiple choice options. What type of data is this?
A: Nominal variable
Q: What does a scatterplot show the association between?
A: Two continuous variables
Q: What is the opposite of bias?
A: Precision
Q: What type of sampling is placing flyers around UofL and your neighborhood for recruitment?
A: Convenience sampling
Q: Which is true of stratified random sampling?
A: It ensures sufficient numbers of underrepresented groups by assigning them higher probabilities of selection.
Q: What does the difference between estimated and true prevalence in a study indicate?
A: It could be due to both random error and bias.
Q: A synonym for bias is?
A: Systematic error
Q: Label the variable 'Age' as Q-D, Q-C, or L.
A: Q-C (Quantitative, Continuous)
Q: Label the variable 'Number of times exercised last week' as Q-D, Q-C, or L.
A: Q-D (Quantitative, Discrete)
Q: Label the variable 'Education level' as Q-D, Q-C, or L.
A: L (Qualitative)