Power Points chapter

What is the definition of epidemiology?

The study of the distribution and determinants of disease and health states in populations.

What are the 5Ws of epidemiology?

Who, Where, When, Why, What.

What is the difference between medicine and epidemiology?

Medicine focuses on individuals; epidemiology focuses on populations.

What are descriptive and analytic epidemiology?

Descriptive describes patterns (who, where, when); analytic investigates causes (why).

Who is John Snow and what did he do?

Founder of modern epidemiology; identified water as the source of cholera in London using a spot map.

What is a risk factor?

Behavior, exposure, or characteristic increasing disease risk.

What are modifiable and non-modifiable risk factors?

Modifiable can be changed (e.g., diet); non-modifiable cannot (e.g., age).

What are the types of data used in epidemiology?

Qualitative (Nominal, Ordinal) and Quantitative (Continuous, Discrete, Dichotomous).

What are measures of central tendency?

Mean, Median, Mode.

What is standard deviation?

Measure of data spread from the mean.

What is a histogram?

A graph displaying the frequency distribution of a continuous variable.

What is a contingency table?

A table showing the relationship between two categorical variables.

What is the difference between accuracy and precision?

Accuracy is how close a measurement is to the true value; precision is the consistency of repeated measurements.

What is a parameter?

A number summarizing a population.

What is a confidence interval?

A range estimating the population parameter with a certain confidence level (e.g., 95%).

What is a null hypothesis (H0)?

The statement that there is no effect or association.

What is a Type I error?

Rejecting a true null hypothesis.

What is correlation?

Strength and direction of a linear relationship between two variables.

What is a chi-square test used for?

Testing independence between two categorical variables.

What is incidence?

Rate of new cases in a population over time.

What is prevalence?

Proportion of existing cases in a population at a specific time.

What is point prevalence?

Prevalence at a specific point in time.

What is cumulative incidence (risk)?

Number of new cases / population at risk over a time period.

What is attack rate?

Proportion of people who develop disease during an outbreak.

What is case fatality rate?

Proportion of people with a disease who die from it.

How is incidence rate calculated?

New cases / person-time at risk.

What is the relationship between prevalence and incidence?

Prevalence ≈ Incidence × Duration.

How can prevalence increase while incidence decreases?

If disease duration increases (e.g., better treatments).

What is age standardization?

Adjusting rates to eliminate age differences when comparing populations.

What is a crude rate?

Simple, unadjusted rate.

What is a direct age adjustment?

Applying age-specific rates to a standard population.

What is an indirect age adjustment?

Applying standard age-specific rates to a study population.

What are examples of data sources in epidemiology?

U.S. Census, NHIS, NHANES, NVSS, BRFSS.

What is the purpose of public health surveillance?

Ongoing data collection to monitor health events.

What is the role of the Institutional Review Board (IRB)?

Protect human subjects in research.

What is big data in epidemiology?

Large, complex datasets used to analyze health patterns.

What is descriptive epidemiology?

Study of disease distribution by person, place, and time.

What are examples of person variables?

Age, sex, race, SES.

What are examples of place variables?

International, urban-rural, localized patterns.

What are examples of time variables?

Secular trends, seasonal trends, point epidemics, clustering.

What are the types of descriptive studies?

Case reports, case series, cross-sectional studies.

What is causality?

The relationship between a cause and an effect.

What is a necessary cause?

A factor required for an outcome to occur.

What is a sufficient cause?

A factor that alone can produce the outcome.

What is a confounder?

A third variable causing a false association.

What are Bradford Hill’s Criteria for Causality?

Strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, analogy.

What is the web of causation?

Model showing multiple interacting causes of disease.

What is stochastic (probabilistic) causality?

Causality involving randomness and probability.