# Presentation: 915320

## Heart Disease and Stroke in Healthy People 2010: A look at age adjustment issues 

- Elizabeth Jackson
- John Aberle-Grasse, MPH
- National Center for Health Statistics

## What we’ll cover

- What is age adjustment?
- Why is age adjustment used in Healthy People?
- What are the major age adjustment issues for Heart Disease and Stroke and the other HP focus areas?

## Age adjustment (using the direct method)

- 	The application of observed age-specific rates to a standard age distribution to eliminate differences in crude rates in populations of interest that result from differences in the populations’ age distribution.

## Calculation of age-adjusted rate

- Age-adjusted rate =
- i (mi*wsi)
- mi  = di / pi * 100,000
- wsi = standard population weight in age group i
- di   = deaths (or other event) in age group i
- pi   = population in age group i

## Age-adjusted death rate calculations: Stroke deaths (ICD-10 I60-I69) United States, 2000

## Percent distribution of the population by age, sex and race/ethnicity: United States, 2000

- Male

- Female

- Female

- Male

- Hispanic

- White,
- non-Hispanic

- Age
- (years)

- Source: Current Population Survey, March 2000, U.S.Bureau of the Census.

## Percent distribution of the population by age and sex : United States, 1940 and 2000

- Source: National Vital Statistics Report, Vol. 47, No. 3, October 7, 1998, National Center for Health Statistics, CDC.

## Age adjusted rate

- Weighted average of age-specific rates

- *Strokes are classified by ICD-10 codes: I60-I69.
- Source: National Vital Statistics Surveillance System, National Center for Health Statistics, CDC.

- Black,
- non-Hispanic

- Hispanic

- Asian or
-  Pacific Islander

- American Indian
- or Alaska Native

**Age adjusted rate of stroke* deaths per 100,000 population, by race:          United States, 2000**

- White,
- non-Hispanic

- Provides a single number for easy comparison

- Should be viewed as   a construct or index rather than actual or direct measure

**2010**
**Target**

## Stroke* deaths: United States, 2000

- Age-adjusted
- rate per 100,000

- 40-57

- 58-61

- 62-67

- 68-83

- *Strokes are classified by ICD-10 codes: I60-I69.
- Source: National Vital Statistics Surveillance System, National Center for Health Statistics, CDC.

**Notes:**
NY (42.1)
NJ (47.5)
only States to exceed HP2010 target (48)

## Statistical, new and interesting!

- Standard population change
- Expanded beyond mortality in HP2010
- Chronic condition denominators

## Standard population 

- NCHS in the past
- mortality data used 1940 standard
- survey data used mostly 1970 & 1980 standard
- NCHS now uses year 2000 US resident population as standard for all age adjustment
- 2000-adjusted rates better reflect national demographics and current crude rates

## Crude and age adjusted death rates based onyear 1940 and 2000 standard populations: United States, 1979-2000

- Crude and age adjusted death rates based onyear 1940 and 2000 standard populations: United States, 1979-2000

**1940 standard**

**2000 standard**

**crude rate**

- Rate per 100,000 population

## Age adjusted coronary heart disease* death rates per 100,000 standard population:

- *Heart disease is classified by ICD-9 codes: 402, 410-414, 429.2.
- Source: National Vital Statistics Surveillance System, National Center for Health Statistics, CDC.

- United States, 1998

**1940 standard**

**2000 standard**

- Black

- Hispanic

- Asian or
-  Pacific Islander

- American Indian
- or Alaska Native

- White

- Black

- Hispanic

- Asian or
-  Pacific Islander

- American Indian
- or Alaska Native

- White

## Mortality data

Health outcomes, risk factors, and health services data

Main purposes:
Observe trends in populations over time
Monitor disparity both at a point in time and over time

- Health outcomes, risk factors, and health services data
- Main purposes:
- Observe trends in populations over time
- Monitor disparity both at a point in time and over time

- Expansion in Healthy People 2010

**Notes:**
Several different age groupings are used to age-adjust data from different sources

## Blood cholesterol screening in past 5 years: Adults 18 years and over, 1998

- Age-adjusted percent

- NOTE: I is 95% confidence interval.

- SOURCE: National Health Interview Survey, NCHS, CDC.

**2010**
**Target**

- Hispanic

- Asian or
-  Pacific Islander

- American Indian
- or Alaska Native

- Black,
- non-Hispanic

- White,
- non-Hispanic

**Total**

**Notes:**
Very little difference by race.  

For all groups about 60% have had blood cholesterol checked in the past 5 years.

## Standard population: age distributions and chronic conditions

- Several different age groupings are used to age-adjust data from different sources
- Some data sources use fewer age groupings to stabilize the rates of less common events and smaller subpopulations (e.g. age groups for chronic disease)

## Slide 17

## Slide 18

## Hispanics 2 years and over with diabetes who have seen a dentist in the past year (Obj. 5-15)

- SOURCE: National Health Interview Survey, NCHS, CDC.

**Age-Adjusted**

**Crude**

## Hispanics 2 years and over with diabetes who have seen a dentist in the past year (Obj. 5-15)

- SOURCE: National Health Interview Survey, NCHS, CDC.

## Hispanics 2 years and over with diabetes who have seen a dentist in the past year (Obj. 5-15)

- SOURCE: National Health Interview Survey, NCHS, CDC.

**< 45 separate**

**Crude**

**< 45 combined**

## Slide 22

## Controlled high blood pressure: 

- Controlled high blood pressure:
- Adults 18 and over, 1988-94

- Age-adjusted percent

- Gender

- Female

- Male

- Near poor

- Poor

- With diabetes

**Total**

- Middle/high income

- Without diabetes

- NOTE: I is 95% confidence interval.

- SOURCE: National Health and Nutrition Examination Survey, NCHS, CDC.

**Notes:**
Although males have more HBP...females much more likely to be under control

Income gradient...

P w/ diabetes much more likely to be under control (more regular medical care?)

## Elizabeth Jackson

- National Center for Health Statistics
- Division of Health Promotion Statistics
- 6525 Belcrest Rd., Rm. 770
- Hyattsville, MD 20782
- e-mail:  EMJackson@cdc.gov

**NCHS Healthy People 2010**
- _www.cdc.gov/nchs/hphome.htm_

**DATA2010**
- _wonder.cdc.gov/data2010_

**DHHS Healthy People 2010**
- _www.health.gov/healthypeople_