Gordis Epidemiology (Chpt 1-8)

Front 1

Endemic

Back 1

Habitually present in human populations

Front 2

Attack rate formula?

Back 2

# Sick / # Exposed

Front 3

In an ID outbreak, why is plotting the epidemic curve useful?

Back 3

1. Helps determine the source (single source, person-to-person, etc)

2. Helps determine the median incubation period

Front 4

Characteristic of a single source common vehicle outbreak (the one highlighted in Gordis questions)

Back 4

Explosive

Front 5

1000 Same age men and women get an exam and 5/1000 men have migraines while 10/1000 women do.

Why can't you say women have twice the risk of migraine?

Back 5

This is prevalence, risk is a characteristic of incidence.

Front 6

Calculate incidence given an incidence rate.

Back 6

Annual incidence rate x population in a given year.

i.e. 5/100,000 x 2 million = 100 new cases that yr

Front 7

Does active surveillance reduce reporting burden on healthcare providers?

Back 7

YES! This is when PH officials go out to clinics/hospitals to perform "case finding"

Front 8

If you are calculating age specific incidence and you exclude people who cannot get the disease (perhaps they don't have the target organ)--what happens to your incidence rate?

Back 8

Increases (smaller denominator)

Front 9

20's have 20% HTN

30's have 25% HTN

Can we say there is an age-related HTN risk?

Back 9

No, this is again confusing prevalence and incidence

Incidence is related to risk

Front 10

incidence rate formula?

Back 10

# new cases during time period / Population at median time point

Front 11

Mortality rate for disease is 10/100,000 in one city and 100/100,000 in another, both in the same age group. Why can't you say the disease is two times as prevalent?

Back 11

Failure to distinguish prevalence and mortality

Front 12

How do incidence and mortality rates compare for a disease like pancreatic cancer?

Back 12

They will be similar since many cases in the time period will die within the time period.

Front 13

SMR (acronym and formula)

Back 13

Standardized Mortality Ratio

Observed # deaths per year / Expected # of deaths per year

(can compare similar groups, i.e. white miners and white men in general for Lung CA)

Front 14

In factory workers, there are 100 cancer deaths, 10 stomach (10%), 50 lung (50%), 30 colon (30%), 10 bladder (10%).

What type of data is this?

Back 14

Proportionate mortality

Front 15

What measurement would be useful in an intervention aiming to reduce premature disability?

Back 15

DALY

Front 16

In 2010 in Community X, 10 of 1000 young people die from plague and 60 of 100 old people die from plague...

how do you calculate age-adjusted death rate?

Back 16

10 + 60 / 1000 + 100 = .064 = 64/1000

Front 17

Net Specificity formula (SEQUENTIAL)

Back 17

(Spec test 1 + Spec test 2) - (Spec test 1 x Spec test 2)

Front 18

Net Sensitivity formula (Simulataneous)

Back 18

(Sens test 1 + Sens test 2) - (Sens test 1 x Sens test 2)

Front 19

Net Sensitivity formula (Sequential)

Back 19

Sens1xSens2

Front 20

Net Spec formula (Simultaneous)

Back 20

Spec1xSpec2

Front 21

What are the kappa ranges?

Back 21

k < .40 is poor

0.40 < k < 0.75 is good

k > .75 is excellent

Front 22

Bizz-buzz, historical epi people:

1. Aristotle

2. Leuwenhoek

3. Jenner

4. Snow

5. Semmelweis

6. Pasteur

7. Fleming

8. John Graunt

Back 22

1. Aristotle--Spontaneous generation miasma

2. Leuwenhoek--Early microbio theory

3. Jenner--Immunology/Smallpox vaccine

4. Snow--Broad st pump/Father of Epi

5. Semmelweis--Infection control/handwashing

6. Pasteur--Germ theory

7. Fleming--PCN/Abx

8. John Graunt--First demographer, London bills of mortality

Front 23

Holy trinity in epidemiology?

Back 23

Agent, Host, Environment (vector at the center)

Front 24

_______________ is a measure of virulence.

Back 24

Case fatality rate (severe or fatal cases / total cases)

Case fatality rate APPROXIMATES virulence

Front 25

Pathogen goes endemic, epidemic or extinct if:

1) Ro = 1

2) Ro < 1

3) Ro > 1

Back 25

1) Ro = 1 --> Endemic

2) Ro < 1 --> Extinct

3) Ro > 1 --> Epidemic

Front 26

Herd Immunity Proportion Formula

Back 26

1 - (1/Ro)

Front 27

On a single vector outbreak curve, what do the relatively few outlier boxes at the beginning and end represent?

Back 27

Likely index case (early) and a few secondary cases (late)

Front 28

Passive surveillance?

Back 28

Providers report illnesses to central PH agency

Front 29

Active surveillance

Back 29

PH staff are deployed to investigate outbreaks (case finding)

Front 30

Incidence is synonymous with _________.

Back 30

Disease risk (i.e. Absolute risk: Prob an individual will get the disease. Relative risk: Ratio of contracting a disease for an exposed vs unexposed person)

Front 31

CDR vs CFR?

Back 31

CDR = # dead/Population for a time period

CFR = #exposed who died / # exposed

Front 32

Age adjusted death rates are _____________.

Back 32

Hypothetical

Front 33

Accuracy and Precision in Epi-Speak?

Back 33

Validity and Reliability

Front 34

Secondary attack rate is a measure of __________

Back 34

Infectivity

Front 35

9,785 people in a community of 1,056,039 have diabetes, calculate prevalence as a %.

Back 35

9,785/1,056,039 x 100 = 9.27%

Front 36

Cumulative incidence formula and examples of 2 other terms that are really cumulative incidences.

Back 36

# NEW cases / # persons at risk during a defined period

Examples:

Period prevalence: Have you had flu in in the past n years?

Lifetime prevalence (have you ever had flu?) is also a cumulative incidence.

Front 37

Incidence rate formula

Back 37

# new cases counted during follow-up / total time at risk experienced by individuals in the population

Ex: 5 people studied for various lengths of time (total = 3.25 person years), 3 get the disease during study, the 3/3.25 = 0.92 = INCIDENCE RATE

Front 38

Denominator in cumulative incidence?

Denominator in Incidence Rate?

Back 38

cumulative incidence --> People at risk during defined period

Incidence Rate --> Person-time at risk

Front 39

How are prevalence and incidence related (hint: formula)

Back 39

Prevalence = Incidence x duration of disease (deaths, emigrations and recovery can confound)

Front 40

Crude birth rate formula

Back 40

(# live births in a given year / total MIDYEAR resident population) x 1000

Front 41

Expected death for population P formula?

Back 41

(P age specific death rate x US standard population for that age interval) / 100,000

Front 42

Kappa statistic formula

Back 42

(% observed agreement- % expected agreement) / (100% - % expected agreement)