Public Health

Question 1

Relative Risk (RR)

Answer 1

An estimate of the magnitude of an association between exposure and outcome.
Likelihood of developing outcome for the exposed relative to the unexposed.

Question 2

Absolute Risk Reduction (ARR)

Answer 2

DIFFERENCE in incidence of outcome between exposed and unexposed.

Question 3

Number Needed to Treat (NNT)

Answer 3

Number of patients needed to be treated in order to prevent ONE adverse outcome (incidence)

Question 4

Efficacy

Answer 4

Combination of RR and ARR. How much of the risk in placebo (exposed) group is reduced by the new treatment (unexposed)?

Question 5

How does RR measure the strength of an association?

Answer 5

The RR tells us how much more/less likely two variables are related. (Strength of etiologic association)

Question 6

How does ARR measure the strength of an association?

Answer 6

ARR will evaluate the actual impact of applying one variable to the other. (ie. treatment group had 2% less bad outcomes than placebo)

Question 7

Population Attributable Risk (PAR)

Answer 7

Indicates proportion of the risk in the GENERAL POPULATION that would be removed if exposure was eliminated.
This is “efficacy.”

Question 8

Which is most important to public health?: RR, ARR, or PAR?

Answer 8

PAR- Population attributable risk

Question 9

Association

Answer 9

Statistical dependence between 2 variables. Does not show causality.

Question 10

Type 1 Error (alpha)

Answer 10

False Positive. We note they are different when they aren’t.

Question 11

Type 2 Error (beta)

Answer 11

False negative. We note they aren’t different when they are.

Question 12

Hypothesis Testing Steps (3)

Answer 12

1. Define null hypothesis
2. Calculate probability of observed data if null were true (ie. “tinker plot”)
3. Look at p-value

Question 13

Standard Error (SE) vs Standard Deviation (SD)

Answer 13

SE is this standard distribution of a sampling distribution. Standard deviation is the standard deviation of a set of data from 1 sample.

Question 14

Confidence Interval

Answer 14

Estimated range of values likely to include an unknown population parameter.
Values calculated from sample data.

Question 15

Statistical Power

Answer 15

The probability of correctly concluding that there is a difference. (1-beta)

Question 16

What are the 3 forms of community?

Answer 16

1. Proximity
2. Identity
3. Purpose

Question 17

Communities of Proximity

Answer 17

Things that are close together have similar interests and concerns. (This is easy to do, but you make a lot assumptions-bad)

Question 18

Communities of Identity

Answer 18

Comprise communities of who you are/identify with; can be very intimate. (Very hard to define)

Question 19

Communities of Purpose

Answer 19

A group working toward a goal. Clear organizational structure., but limited resources.

Question 20

Cultural Competence

Answer 20

A set of congruent behaviors, attitudes, and policies that come together in a system, agency, or among professionals that enables effective work in cross-cultural situations

Question 21

Clinical Diagnosis

Answer 21

Identifying diseased/non-diseased people among patients WITH SYMPTOMS

Question 22

Screening

Answer 22

The examination of a group of usually asymptomatic individuals to detect those with a high change of having or developing the disease. (ie. physical exam, questionnaire, fluid assays-ie. blood, urine)

Question 23

Validity

Answer 23

Probability that a test correctly identifies those with and without disease. (lacks bias)

Question 24

Reliability

Answer 24

Test reproducibility: When the test is repeated, you can expect the same result. (lacks random error)

Question 25

Two measures of Validity

Answer 25

1. Sensitivity (Probability of obtaining true positive) | 2. Specificity (Probability of obtaining true negative)

Question 26

The "Gold Standard"

Answer 26

External source of "truth" regarding disease status of each individual in a population. (This test is very hard to perform)

Question 27

Positive Predictive Value

Answer 27

Proportion of people with disease among those who test positive. Probability that patient truly has disease.

Question 28

Negative Predictive Value

Answer 28

Proportion of people without disease among those who test negative. Probability that patient truly doesn't have disease.

Question 29

Likelihood Ratio (LR)

Answer 29

How many times more likely is a positive test result is to be found in diseased individuals, compared to non-diseased individuals.

Question 30

Lead Time Bias

Answer 30

The appearance that early diagnosis of disease will prolong survival with that disease.

Question 31

Likelihood Ratio Equation

Answer 31

(sensitivity) / (1-specificity)

Question 32

Positive Predictive Value Equation

Answer 32

PPV= (# correctly screened positive) / (total # screened positive)

Question 33

Negative Predictive Value Equation

Answer 33

NPV= (# correctly screened negative) / (total # screened negative)

Question 34

Sensitivity Equation

Answer 34

(# Correct Positives) / (Actual # positive)

Question 35

Specificity Equation

Answer 35

(# Correct Negatives) / (Actual # Negative)

Question 36

Definitions of Public Health (3)

Answer 36

1. 1988 Fulfilling society's interest in assuring conditions in which people can be healthy. 2. Successive re-defining of the unacceptable (1958) 3. Turnock: "It depends.."

Question 37

Lenses to view public health (4)

Answer 37

1. Government View 2. Market justice view 3. Social justice view 4. Political View

Question 38

Explain the "Epidemiologic Triad?"

Answer 38

The idea that diseases have multiple causes. (Environment Agent Host [Vector])

Question 39

Why weren't Koch's postulates enough to explain disease?

Answer 39

It was not as simple as "bacteria being present to cause disease"

Question 40

Define Evidence-Based Medicine

Answer 40

Conscientious, explicit, and judicious use of current best evidence in medical decision-making

Question 41

Hierarchy of Evidence (Most Valid at the top)

Answer 41

``` (most valid) 1. Systematic Review 2. Randomized Control Trial (RCT) 3. Cohort Study 4. Case-Control Study 5. Physiologic Study 6.Unsystematic Clinical Observation (most bias) ```

Question 42

EBM Process (5 A's)

Answer 42

1. Assess (knowledge gaps) 2. Ask (an answerable question;PICO patient intervention comparison outcomes) 3. Acquire (find evidence) 4. Appraise (determine evidence quality) 5. Apply (evidence to patient)

Question 43

Analytic vs Descriptive Epidemiology

Answer 43

Determinants of health and disease vs Distribution of health and disease

Question 44

4 Reasons to Break Confidentiality

Answer 44

1. High Probability 2. Serious Injury 3. Intervention 4. Last Resort