Mortality Rates and Ratios

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Chapter 4

• Mortality Rates and Ratios

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Mortality Data Figure 4.1

• What is mortality data tell us?
• Where does it come from?
• What are the variables here?
• What are the units of measurement?

• What numbers were needed to calculate the
  figures?
• Who has the highest mortality rates?

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What are rates?
Number of cases
X
100,000
Population in question
Measured over a period of time
Number might be 100, 1000, 100,000
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Type of Mortality Data
Note Table 4.2
Crude Rates Adjusted Rates Specific Rates
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Ratios
Generally not as useful as rates Its a comparison
of one item to another Sometime used in
assessment of risk
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Proportions

• A comparison of similar things
• often expressed as a percentage
• might be used in its decimal form 0 to 1.0
• A pie chart is a good graphical example

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Assessment of Mortality

• Concept of Vital Statistics
• Death Certificates
• ICD-9CM Sources
• What happens to the data?

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Crude Death Rates
2,175,000
X
100,000
245,000,000
888 deaths per 100,000
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Infant Mortality Rates
Number of child deaths lt 1 year of age
IMR
1,000
X
Number of live births
What are the trends in the US? Industrialized
nations?
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Infant Terms

• IMR lt 1 year of age
• Neonatal lt 28 days old
• Postnatal gt28 days up to 1 year
• Perinatal fetal deaths gt28 weeks gestation
  plus postnatal deaths

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Maternal Mortality

• Compare to other industrialized nations?
• How has managed care changed this?

Deaths from childbirth (42 days)
X
100,000
MM

Total number live births
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Specific Mortality Rates

• Gompertzs Law (figure 4.1)
• Age Specific rates (ages 15-24)
• Proportionate mortality rate
• 10 deaths out of 40 from cancer
• Cause specific rates (drownings age 1-4)