Power Points chapter

Class 2 – History and Uses of Epidemiology

Q: What is the definition of epidemiology?
A: The study of the distribution and determinants of disease and health states in populations.

Q: What are the 5Ws of epidemiology?
A: Who, Where, When, Why, What.

Q: What is the difference between medicine and epidemiology?
A: Medicine focuses on individuals; epidemiology focuses on populations.

Q: What are descriptive and analytic epidemiology?
A: Descriptive describes patterns (who, where, when); analytic investigates causes (why).

Q: Who is John Snow and what did he do?
A: Founder of modern epidemiology; identified water as the source of cholera in London using a spot map.

Q: What is a risk factor?
A: Behavior, exposure, or characteristic increasing disease risk.

Q: What are modifiable and non-modifiable risk factors?
A: Modifiable can be changed (e.g., diet); non-modifiable cannot (e.g., age).


Class 3 – Data Presentation

Q: What are the types of data used in epidemiology?
A: Qualitative (Nominal, Ordinal) and Quantitative (Continuous, Discrete, Dichotomous).

Q: What are measures of central tendency?
A: Mean, Median, Mode.

Q: What is standard deviation?
A: Measure of data spread from the mean.

Q: What is a histogram?
A: A graph displaying the frequency distribution of a continuous variable.

Q: What is a contingency table?
A: A table showing the relationship between two categorical variables.

Q: What is the difference between accuracy and precision?
A: Accuracy is how close a measurement is to the true value; precision is the consistency of repeated measurements.

Q: Name a common sampling method.
A: Simple random sample.


Class 4 – Statistics

Q: What is a parameter?
A: A number summarizing a population.

Q: What is a confidence interval?
A: A range estimating the population parameter with a certain confidence level (e.g., 95%).

Q: What is a null hypothesis (H0)?
A: The statement that there is no effect or association.

Q: What is a Type I error?
A: Rejecting a true null hypothesis.

Q: What is correlation?
A: Strength and direction of a linear relationship between two variables.

Q: What is a chi-square test used for?
A: Testing independence between two categorical variables.


Class 5 – Measures of Disease Occurrence

Q: What is incidence?
A: Rate of new cases in a population over time.

Q: What is prevalence?
A: Proportion of existing cases in a population at a specific time.

Q: What is point prevalence?
A: Prevalence at a specific point in time.

Q: What is cumulative incidence (risk)?
A: Number of new cases / population at risk over a time period.

Q: What is attack rate?
A: Proportion of people who develop disease during an outbreak.

Q: What is case fatality rate?
A: Proportion of people with a disease who die from it.


Class 6 – Prevalence & Incidence

Q: How is incidence rate calculated?
A: New cases / person-time at risk.

Q: What is the relationship between prevalence and incidence?
A: Prevalence ≈ Incidence × Duration.

Q: How can prevalence increase while incidence decreases?
A: If disease duration increases (e.g., better treatments).


Class 7A – Age Standardization

Q: What is age standardization?
A: Adjusting rates to eliminate age differences when comparing populations.

Q: What is a crude rate?
A: Simple, unadjusted rate.

Q: What is a direct age adjustment?
A: Applying age-specific rates to a standard population.

Q: What is an indirect age adjustment?
A: Applying standard age-specific rates to a study population.


Class 7B – Data Sources

Q: What are examples of data sources in epidemiology?
A: U.S. Census, NHIS, NHANES, NVSS, BRFSS.

Q: What is the purpose of public health surveillance?
A: Ongoing data collection to monitor health events.

Q: What is the role of the Institutional Review Board (IRB)?
A: Protect human subjects in research.

Q: What is big data in epidemiology?
A: Large, complex datasets used to analyze health patterns.


Class 8 – Descriptive Epidemiology

Q: What is descriptive epidemiology?
A: Study of disease distribution by person, place, and time.

Q: What are examples of person variables?
A: Age, sex, race, SES.

Q: What are examples of place variables?
A: International, urban-rural, localized patterns.

Q: What are examples of time variables?
A: Secular trends, seasonal trends, point epidemics, clustering.

Q: What are the types of descriptive studies?
A: Case reports, case series, cross-sectional studies.


Class 9 – Causality

Q: What is causality?
A: The relationship between a cause and an effect.

Q: What is a necessary cause?
A: A factor required for an outcome to occur.

Q: What is a sufficient cause?
A: A factor that alone can produce the outcome.

Q: What is a confounder?
A: A third variable causing a false association.

Q: What are Bradford Hill’s Criteria for Causality?
A: Strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, analogy.

Q: What is the web of causation?
A: Model showing multiple interacting causes of disease.

Q: What is stochastic (probabilistic) causality?
A: Causality involving randomness and probability.