Epidemiology

Question 1

Prevalence

Answer 1

=(all cases present at time point)/(total # of unit at that time)

Question 2

Cumulative Incidence

Answer 2

=(# events during period of time)/(pop w/o dz at begin of time)

Question 3

Attact rate

Answer 3

=(# of cases)/(total # of subject exposure)

Question 4

Relative risk

Answer 4

cohort studies
=(A/A+B)/(C/C+D)
neg assoc <1
1 = no associ
pos assoc > 1

Question 5

Odds Ratio

Answer 5

Case-control studies
=(AD)/(BC)
neg assoc <1
1 = no associ
pos assoc > 1

Question 6

Risk difference

Answer 6

=Risk exp - risk unexp

Question 7

Attributable risk %

Answer 7

=(RR-1)/RR

Question 8

Population attributable risk %

Answer 8

=(Risk overall - Risk unexp)/Risk Overall

Question 9

Prevented fraction

Answer 9

=1-RR

Question 10

PPV

Answer 10

=TP/(TP+FP)

Question 11

NPV

Answer 11

=TN/(TN+FN)

Question 12

Sensitivity

Answer 12

=A/(A+C)

Question 13

Specificity

Answer 13

=D/(B+D)

Question 14

Mortality Rate

Answer 14

=(total # deaths from all causes in 1 year)/(pop at mid year)

Question 15

Case-fatality rate

Answer 15

=(# deaths after dz onset or dx)/(#ind with the dz)

Question 16

Incidence rate

Answer 16

=(#new events)/(total person-time at risk in pop)

Question 17

proportionate mortality

Answer 17

=(# death from sp dz in time period)/(total # death in tat time period)

Question 18

Type I error

Answer 18

False positive, alpha

Question 19

Type II error

Answer 19

False negatvie, beta

Question 20

Power

Answer 20

=1-beta

Question 21

Outbreak Steps

Answer 21

1. Prep for fieldwork
2. Estimate the existence of outbreak
3. Verify Dx
4. Define and identify cases
5. Describe and orient the data in terms of time, place, and subject
6. Develop hypotheses
7. Evaluate Hypotheses
8. Refine hypothesis and carry out studies
9. Implement control and prevention measures
10. Communicate findings