Homework 1

Who identified the cause of a cholera outbreak as contaminated water from the Broad Street pump?

John Snow

What is the spot map of London and cholera an example of?

Descriptive epidemiology, because it visually represents cases without testing hypotheses.

What was Edward Jenner’s contribution to science/epidemiology?

He developed the first successful smallpox vaccine by using material from cowpox lesions.

What is the most specific name of a figure showing the number of incident Zika cases by day?

Epidemic curve.

What did the author predict would eventually happen with COVID-19?

COVID-19 would likely become endemic, persisting but at lower, manageable levels.

Define 'Endemic' and provide three examples of endemic diseases in the U.S.

Endemic refers to a disease regularly found in a particular area. Examples: Influenza, Lyme disease, and Chickenpox.

Who isolated the bacteria causing anthrax and developed four postulates for disease causation?

Robert Koch.

Define 'epidemiologic transition'.

A shift from mostly communicable to mostly chronic diseases in a population.

Define 'demographic transition'.

A shift from high birth and death rates to low birth and death rates.

What is the primary advantage of using toenail clippings vs. blood for assessing lead exposure?

Toenail clippings provide a longer-term measure of lead exposure compared to blood.

Which way of measuring lead exposure (toenails vs blood) was more strongly associated with children’s cognitive performance?

Blood levels were more strongly associated with cognitive performance.

Why might blood be a more accurate biomarker of lead exposure than toenails?

Blood reflects recent exposure and is more directly linked to physiological effects.

What is the official term for a table presenting oral cancer cases and alcohol intake?

Contingency table.

What is the official term for a figure showing frequency distribution?

Histogram.

In a standard normal distribution, what percentage of data falls within 1 SD of the mean?

Approximately 68%.

In a skewed distribution, which direction is the skew if the tail is on the right?

Right skewed.

What type of variable is the response to 'How bad do you feel on a scale from 1 to 10?'

Ordinal variable.

What type of data is the response to 'How do you feel?' with multiple choice options?

Nominal variable.

What does a scatterplot show the association between?

Two continuous variables.

What is the opposite of bias?

Precision.

What type of sampling is placing flyers around UofL and your neighborhood for recruitment?

Convenience sampling.

What is true of stratified random sampling?

It ensures sufficient numbers of underrepresented groups by assigning them higher probabilities of selection.

What does the difference between estimated and true prevalence in a study indicate?

It could be due to both random error and bias.

A synonym for bias is?

Systematic error.

Label the variable 'Age' as Q-D, Q-C, or L.

Q-C (Quantitative, Continuous).

Label the variable 'Number of times exercised last week' as Q-D, Q-C, or L.

Q-D (Quantitative, Discrete).

Label the variable 'Education level' as Q-D, Q-C, or L.

L (Qualitative).