Epi

Question 1

epidemiology is?

Answer 1

studies:

• distribution
• determinants (risk factors)

Question 2

Distribution of dz

Answer 2

• frequencies of dz occurrences- in relation to SIZE of pop!

- patterns of dz occurrences- person, place, time-> Descriptive epidemiology!!

Question 3

Descriptive epidemiology

Answer 3

-person, place, time

Question 4

Passive surveillance systems

Answer 4

-public health system passively waits for reports to come in

Question 5

Active surveillance systems

Answer 5

-public health officials go into communities to search for new dz/condition cases

Question 6

Syndromic Surveillance system

Answer 6

-looks for signs/sx’s of pts related to the dz

Question 7

Epidemic

Answer 7

-occurrence of dz in excess of normal!!

Question 8

Outbreak

Answer 8

• epidemic limited to a LOCALIZED inc in occurrence of dz

- also called cluster

Question 9

Endemic

Answer 9

-CONSTANT presence of dz in a given area that is in excess of normal levels in other areas

Question 10

Emergency of International Concern

Answer 10

-epidemic that alerts the world to the need for high vigilance

Question 11

Pandemic

Answer 11

Pandemic

-an epidemic spread world-wide

Question 12

analytic epidemiology

Answer 12

-why/how

Question 13

Proportions vs ratios

Answer 13

• proportions- division of 2 related numbers

- ratios- division of 2 unrelated numbers

Question 14

Incidence vs prevelance

Answer 14

• incidence- NEW occurrences
• prevalence- old and new cases
• point prevalence- at a given point in time
• period prevalence- over a given period of time

Question 15

Calculate incidence

Answer 15

= # of new cases of illness / # of ppl at risk of illness

those not at risk- already have it or are immune

Question 16

Calculate prevelance

Answer 16

= total # of cases of illness / # of ppl in population

Question 17

Exposure and Disease (table)

Answer 17

• probability of an outcome in Exposed

- probability of outcome in non-exposed

Question 18

Absolute Risk Reduction (ARR)

Answer 18

(absolute = subtract)

-risk difference b/w groups!!!

Question 19

Relative Risk Reduction (RRR)

Answer 19

= ARR / Runexposed

Question 20

Number Needed to Treat (NNT)

Answer 20

(# of pts needed to be treated to receive the stated benefit/harm)
=1 / ARR (in decimal format)
-ex- 1 / 0.038 = 27 patients (always round up!)

Question 21

Risk Ratio

Answer 21

ratio of the risks from 2 diff groups

= Risk of outcome (in exposed) / Risk of outcome (in non-exposed)

Question 22

Review of Ratios

Answer 22

• ratio > 1.0- MORE likely to occur in numerator group

- ratio < 1.0- LESS likely to occur in numerator group

Question 23

Interpreting ratios

Answer 23

RR (risk), OR (odds), HR (hazard)

• > 1.0- if RR = 1.53, then comparator group is at 53% INC risk
• > 2.0- if RR = 6.18, then comparator group is at 6.18X GREATER odds
• <1.0- if HR = 0.73, then comparator group has a 27% DECREASED probability