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Age-adjusted Rates on IBIS Query System (Directly Age-adjusted)

Age Adjustment Weights (Updated September, 2012)

The age-specific rates for each age group in the study population are multiplied by the proportion of people in the same age group in the standard population distribution. The sum of these products is the age-adjusted, or age-standardized rate. The age-adjusted rate can be considered an average of each of the individual age-specific rates, but rather than being a simple average, it is a weighted average with each age-specific rate weighted by the proportion of people in that age group in the U.S. 2000 standard population.

Age-adjusted rates control for age effects, allowing better comparability of rates across areas. Age-adjustment may also be used to control for age effects when comparing across several years of data, as the age distribution of the population changes over time. Only rates adjusted to the same standard population can be compared. Age adjustment is not appropriate if the age-specific death rates in the population of interest do not have a consistent relationship. The age-adjusted rate is hypothetical, and is useful only for comparing populations, either over time, by geographic area, by sex, or by racial/ethnic subgroups. For more information, see "Health Event Counts and Crude, Age-specific, and Age-adjusted Rates" Help

Age Adjustment Weights The IBIS query system uses the U.S. 2000 standard population weights for all age-adjusted measures.

For more information on age adjustment using the 2000 projected U.S. population, see http://www.cdc.gov/nchs/data/statnt/statnt20.pdf

All weights used on IBIS are from the master list of 2000 U.S. projected and age-adjustedment weights.

U.S. 2000 Standard Population 11 Age Groups Weights (Used by Mortality, Hospital Discharge, ED Encounter, ED Primary Care Sensitive Conditions and UHAS* IBIS Query Modules)


Age Group U.S. 2000 Population Projection
(in thousands)
Weight

1

Under 1 Year

3,795

0.013818

2

1 - 4 Years

15,192

0.055317

3

5 - 14 Years

39,977

0.145565

4

15 - 24 Years

38,077

0.138646

5

25 - 34 Years

37,233

0.135573

6

35 - 44 Years

44,659

0.162613

7

45 - 54 Years

37,030

0.134834

8

55 - 64 Years

23,961

0.087247

9

65 - 74 Years

18,136

0.066037

10

75 - 84 Years

12,315

0.044842

11

85 Years and Over

4,259

0.015508

Total, All ages

274,634

1

Weight=Age-specific Population/Total population in All Age groups



*UHAS normalizes the weights when (1) age restriction has applied to the survey questions. (2) certain age groups have no observations.



U.S. 2000 Standard Population 10 Age Groups Weights (Used by Cancer Registry IBIS Query Modules)


Age Group U.S. 2000 Population Projection
(in thousands, from #1)
Weight

1

0 - 4 Years

18,987

0.069135

2

5 - 14 Years

39,977

0.145565

3

15 - 24 Years

38,077

0.138646

4

25 - 34 Years

37,233

0.135573

5

35 - 44 Years

44,659

0.162613

6

45 - 54 Years

37,030

0.134834

7

55 - 64 Years

23,961

0.087247

8

65 - 74 Years

18,136

0.066037

9

75 - 84 Years

12,315

0.044842

10

85 Years and Over

4,259

0.015508

Total, All ages

274,634

1

Weight=Age-specific Population/Total population in All Age groups



U.S. 2000 Standard Population 8 Age Groups Weights (Used by BRFSS* IBIS Query Modules)


Age Group U.S. 2000 Population Projection
(in thousands)
Weight

1

18 - 24 Years

26,258

0.1288

2

25 - 34 Years

37,233

0.1827

3

35 - 44 Years

44,659

0.2191

4

45 - 54 Years

37,030

0.1817

5

55 - 64 Years

23,961

0.1175

6

65 - 74 Years

18,136

0.0889

7

75 - 84 Years

12,315

0.0604

8

85 Years and Over

4,259

0.0209

Total, 18 years and older

203,851

1

Weight=Age-specific Population/Total population in All Age groups



*BRFSS normalizes the weights when certain age groups have no observations.



U.S. 2000 Standard Population 3 Age Groups Weights (Used by BRFSS IBIS Query Modules When "Race" is Selected)


Age Group U.S. 2000 Population Projection
(in thousands)
Weight

1

18 - 34 Years

63,491

0.3115

2

35 - 49 Years

64,465

0.3162

3

50+ Years

75,895

0.3723

Total

203,851

1

Weight=Age-specific Population/Total population in All Age groups



*BRFSS normalizes the weights when certain age groups have no observations.



U.S. 2000 Standard Population 3 Age Groups Weights (Used by Mortality IBIS Query Modules Including Race)


Age Group U.S. 2000 Population Projection
(in thousands)
Weight

1

0 - 44 Years

178,933

0.651532

2

45 - 65 Years

60,991

0.22.2081

3

65+ Years

30,710

0.126387

Total, All ages

274,634

1

Weight=Age-specific Population/Total population in All Age groups



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The information provided above is from the Department of Health's Center for Health Data IBIS-PH web site (http://ibis.health.state.gov). The information published on this website may be reproduced without permission. Please use the following citation: " Retrieved Tue, 28 March 2017 19:24:05 from Department of Health, Center for Health Data, Indicator-Based Information System for Public Health Web site: http://ibis.health.state.gov ".

Content updated: Tue, 20 Dec 2016 15:48:13 MST