Epid 710 - Lecture 2: Measures Of Disease Occurence And Freq

Front 1

How to measure occurrence?

(5 ways)

Back 1

1. Count
2. Prevalence
3. Odds
4. Risk
5. Rate

Front 2

How to measure Association?

(3 ways)

Back 2

1. Difference
2. Ratio
3. Correlation

Front 3

How to measure Impact?

(3 ways)

Back 3

1. Attributable Fraction
2. Years of potential life lost (YPLL)
3. Disability-adjusted life years (DALY)

Front 4

Definition of Prevalence:

Back 4

how common a condition is within a population over a certain period of time.

Front 5

Formula of Prevalence

Back 5

Prevalence = a/(a+b)
where a --> # of inds w/ disease and b --> # of inds at risk

Front 6

3 types of non-experimental studies

Back 6

1. cohort/prospective study
2. case-control study
3. cross-sectional study

Front 7

Definition of Cohort Study

Back 7

group of healthy people is followed up for a certain time period to ascertain health events.

Front 8

Prevelance Proportion

Back 8

Number of overweights
------------------------------------
Population at risk

Front 9

Prevalence Odds

Back 9

Number of overweights (P)
------------------------------------
Number not overweight (Q)

Front 10

Other names for Risk

Back 10

1. Cumulative Incidence

2. Incidence Proportion

Front 11

Attributable Risk

Back 11

measure of association based on the absolute difference between two risk estimates

Front 12

Relative Risk/ Risk Ratio

Back 12

P(Disease) given Exposure
-----------------------------------------
P(Disease) given Non-Exposure

Front 13

Disease Incidence/ Risk

Back 13

Exposure_Disease
----------------------------------------
Ex_Dis + Ex_NonDis
(i.e. all disease = present kids)

Front 14

Disease Incidence/Risk

Back 14

P(Disease) given Exposure

Front 15

Rate (Incidence Rate, IR)

Back 15

# of people with disease
----------------------------------------
total time at risk for developing

Front 16

Relationship between Prevalence Odds and Incidence Rate

Back 16

PO = IR * Average Duration

(assuming steady state)

Front 17

Relationship between Risk and Incidence Rate

Back 17

Risk = IR * time

Front 18

Definition of Prevalence

Back 18

measures frequency of outcome at either one point in time (point prevalence) or during a period (period prevalence, e.g. lifetime prevalence)

Front 19

Definition of Incidence

Back 19

proportion of newly developed (incident) disease

Front 20

Formula of Incidence Rate

Back 20

Incidence Rate = # of events/ avg. population

Front 21

Formula of Incidence Density

Back 21

Incidence Density = # of events/ total person-time

Front 22

Formula of Rate

Back 22

# events/avg. population
DIVIDED by
time (t)
x/(n*t) = rate/density
(where n*t --> person-years)

Front 23

Rate (in your own words)

Back 23

Is incidence divided by time

Front 24

Component Cause vs. Sufficient Cause

Back 24

Component cause is one that requires exposure to in order to become infected, sufficient cause is pretty self explanatory

Front 25

Induction Period

Back 25

period of time beginning at the action of a component cause and ending when the final component cause acts and the disease occurs

Front 26

Definition of the method of induction

Back 26

looking at cases, arriving at a rule, collecting facts --> leading to a theory

Front 27

Definition of the method of deduction

Back 27

a --> b
b --> c
a --> c

Front 28

Latent Period

Back 28

period between disease occurring and disease being detected