data analysis & interpretation intermediate injury prevention august 23-26, 2011 billings, mt
TRANSCRIPT
Data Analysis&
Interpretation
Intermediate Injury Prevention August 23-26, 2011
Billings, MT
Data Analysis & Interpretation
Session Objectives:
Review basic epidemiologic concepts & terms.
Describe and apply basic statistics to injury prevention.
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
Epidemiology
Population-based
Injuries are not random
Risk
Morbidity v. Mortality
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
Epidemiology:“The study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to control health problems”
Who
Where
When
What
Why
How
- A Dictionary of Epidemiology
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
Epidemiology is POPULATION-BASED (concerned with the community, not the individual).
Leading Causes of UnintentionalInjury Death, Florida, 1999-2006
1. MVC2. Poisoning3. Fall4. Drowning5. Suffocation
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
Injury is not randomly distributed in a population.
0
5
10
15
20
25
30
269 270 271 270 272 272 273 273 274 275
Milepost
Crashes
MP272.5
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
Mortality Morbidity
Fatalities
Data easier to obtain
Tip of the pyramid
Non-fatal
Difficult to obtain
More complete description of the magnitude of the problem
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
Risk:
- A Dictionary of Epidemiology
“The probability that an event will occur.”
Data Analysis & Interpretation
Epidemiologic Concepts & Terms
- A Dictionary of Epidemiology
Risk Factor:“An attribute or exposure…associated with an increased probability of a specific outcome…”
“A determinant that can be modified by intervention, thereby reducing the probability of occurrence of …specified outcomes.”
What’s the Greater Risk?
Data Analysis & Interpretation
Basic Statistics
Rates
YPLL
Numeric Value
Proportions
Data Analysis & Interpretation
Basic Statistics
Numeric Value – (amount)
Easy to understand
Does not indicate risk
Cannot be compared
Very common
Data Analysis & Interpretation
Basic Statistics
Proportional Distribution -
Commonly used
Simple calculation
Not a measure of risk
Sum of all values = 100%
Can be misleading
73 %
N =225
3 %
14 %
Data Analysis & Interpretation
Basic Statistics - Rates
“…comparing apples to oranges…”
Data Analysis & Interpretation
Basic Statistics - Rates
Rate:“An expression of the frequency with which an event occurs in a defined population over a specific period of time and converted to a whole number by multiplying to some power of 10 (usually 10,000 or 100,000).”
- A Dictionary of Epidemiology
Data Analysis & Interpretation
Basic Statistics - Rates
Community A
Community B
Community C
Rate
150 per 100,000
100 per 100,000
50 per 10,000500 per 100,000
Data Analysis & Interpretation
Basic Statistics
Rate
Number of cases
Population at risk(same exposure period)
X 10n or (K)
Data Analysis & Interpretation
Basic Statistics
Rate
17 Cases
13,000 Population(same time period)
X 100,000 Standard Pop.
= 131 per 100,000 population
Data Analysis & Interpretation
Basic Statistics - Rates
Selected Types of Rates
Crude Rate
Specific Rate
Adjusted Rate
Data Analysis & Interpretation
Basic Statistics - Rates
RatesAccurate numerator
Estimated denominator
Used primarily for comparison
Indicator of risk
Data Analysis & Interpretation
Basic Statistics
YPLL = Years of Potential Life Lost
Measure of Premature Death
YPLL = 65 - age at death
Summary
Data Analysis & Interpretation
Epidemiology serves as a foundation
Many data analysis methods
Importance of rates
Communicate your findings
Utilize available resources
Data Analysis Exercise