Module 4

Question 1

Utility of mortality data

Answer 1

• index of severity and risk of disease
• easier to obtain than incidence data
• mortality is a good reflection of incidence rate when case-fatality rate is high and duration of disease is short

Question 2

Epidemiologic transition

Answer 2

Shift in causes of death from infectious communicable diseases to non-infectious non-communicable diseases

Question 3

Mortality data sources (vital stats)

Answer 3

1. Death certificates
2. Birth statistics
   
   • Birth statistics
   • Fetal death certificates

Question 4

Death certificates

Answer 4

Record demographics and cause of death

• immediate cause
• intermediate conditions
• final underlying cause

COD underreported for AIDS and overreported for stroke

Question 5

Birth and Fetal Death Certificates

Answer 5

Used to study environmental influences on congenital malformations (provide nearly complete data)

Limitations:

• Sources of unreliability (inaccurate mother recall and conditions not present at birth)
• Varying state requirements for fetal death certificates

Question 6

Mortality Rate

Answer 6

deaths in a given time period/population in which deaths occurred

• specific period
• expressed per 100; 1,000; 10,000; 100,000

Question 7

Types of mortality rates

Answer 7

1. Crude rates
2. Specific rates
3. Adjusted rates
   
   • Direct
   • Indirect

Question 8

Crude Mortality Rate

Answer 8

Overall unadjusted mortality rate
**Observed differences in crude rates may be the result of systematic factors (ex: sex, age distributions) within the population rather than true variation in rates - caution

(deaths in calendar year/midyear population) x 100,000

Question 9

Specific Mortality Rates

Answer 9

Stratify the population into subgroups using specific factors: age, sex, race, cause of death/illness

Cause-specific rate = (mortality of given disease/population at midpoint of time period) x 100,000

Question 10

Adjusted Rates

Answer 10

Consider population differences between 2+ groups being compared (through standardization)

Standardization allows comparison bet 2 different groups

• Most common by age, sex, or race
• Adjusted by diagnosis, risk, etc.

Question 11

Risk

Answer 11

The probability that an event will occur

Question 12

Adjustment

Answer 12

Mathematical procedures to account for patient differences

*Risk adjustment removes the effect of differences in composition of various populations (compare)

Question 13

How does risk adjustment relate to confounding factors?

Answer 13

Some patient factors are causally related to outcomes

Question 14

Important risk factors

Answer 14

Age
Sex 
Clinical attributes
-principal diagnosis
-comorbidities
-functional/health status

Question 15

Why monitor risk-adjusted outcomes?

Answer 15

• Identify providers whose outcomes are better/worse
• Measure trends in outcomes over time
• Detect and investigate clusters of adverse outcomes
• Identify cross-sectional differences

Question 16

Case-fatality rate

Answer 16

(# deaths due to a cause/total number of cases) x 100

Question 17

Infant mortality rate

Answer 17

(# infant deaths/# live births) x 1,000 live births