Lecture 2, part 5

Question 1

Possible interpretations for incidence increasing but prevalence decreasing

Answer 1

Dz duration is reduced
Dz is becoming more fatal

Question 2

Possible interpretations for incidence stable but prevalence increasing

Answer 2

Slow recovery
Fatality reduced
Immigration of cases from other area

Question 3

Possible interpretations for incidence stable but prevalence declining

Answer 3

Recovery time reduced
Immigration of cases outward to another area

Question 4

What do we need to know for all measures?

Answer 4

Number of ppl affected by the dz
Size of the pop from which the cases arise
Length of time that the pop is followed

Question 5

Definition of incident cases

Answer 5

All individuals who change in status from one state of health to another (such as non-dz to dz) over a specific period of time

Question 6

Definition of prevalent cases

Answer 6

All individuals living with the health outcome of interest within a specified timeframe, regardless of when that person was diagnosed or developed the health outcome

Question 7

What type of measure is mortality rate?

Answer 7

Incidence

Question 8

Numerator of mortality rate

Answer 8

Deaths d/t a specific cause (or all causes)

Question 9

Denominator of mortality rate

Answer 9

Total pop (at risk, but everyone is at risk of death)

Question 10

What type of measure is cause fatality rate?

Answer 10

Cumulative incidence

Question 11

Numerator of case fatality rate

Answer 11

Deaths d/t a specific cause

Question 12

Denominator of case fatality rate

Answer 12

Number of cases of that specific dz

Question 13

Type of measure of attack rate

Answer 13

Cumulative incidence

Question 14

Numerator of attack rate

Answer 14

Number of cases of a dz

Question 15

Denominator of attack rate

Answer 15

Total pop at risk (or exposed) for a limited time period

Question 16

Type of measure for birth defect rate

Answer 16

Prevalence

Question 17

Numerator of birth defect rate

Answer 17

Number of defects at birth

Question 18

Denominator of birth defect rate

Answer 18

All live births

Question 19

Type of measure of survival rate

Answer 19

Cumulative incidence

Question 20

Numerator of survival rate

Answer 20

Number of living cases

Question 21

Denominator of survival rate

Answer 21

Total number of cases of that specific dz

Question 22

Definition of years of potential life lost (YPLL)

Answer 22

Estimate of the avg yrs a person would have lived if they had not died prematurely (measure of premature mortality)

Question 23

Aspects of YPLL

Answer 23

Measure of the overall health of an area
All-cause mortality or cause-specific mortality
Places additional emphasis on deaths of younger persons (mathematically weights the total deaths by applying values to death at each age)

Question 24

Formula for YPLL

Answer 24

YPLL = (avg life expectancy) - (age at death)

Question 25

How is YPLL calculated for a pop?

Answer 25

The YPLL for all individuals who died in that pop is summed

Question 26

How to calculate the YPLL for age groups

Answer 26

Use the midpoint

Question 27

How to use scale in period prevalence

Answer 27

If dz is common, present as percentage
If dz is rare, present as per 1,000, per 10,000, etc.

Question 28

Risk (cumulative incidence definition)

Answer 28

The proportion of an at-risk pop that develops a specific health outcome within a specified amt of time

Question 29

Rate (incidence rate) definition

Answer 29

The frequency of incident cases per unit of person-time at risk, measures how rapidly events are occurring