Trends in childhood asthma: NCHS data on prevalence,

health care use and mortalitySusan Lukacs, DO, MSPH

Lara Akinbami, MD

Infant, Child and Women’s Health Studies Branch, NCHS, CDC

Asthma data available from NCHS data systems

Prevalence Health care utilization

Ambulatory health care Hospitalizations

Mortality

Asthma prevalence

National Health Interview Survey (NHIS)

Continuous multipurpose survey on health conditions, status and behavior

Representative sample of the noninstitutionalized civilian US population

Interviews in >40,000 households – no review of medical records

Parent or responsible adult answers in proxy for children under 18 years of age

Redesigned in 1997 – affected asthma estimates

1980-1996 Redesigned 1997-present

Additional question

2001-presentScreener question:

(None) Has a doctor or other healthprofessional EVER told you that your child had asthma?

Prevalence questions:

During the past 12 mos, did anyone in the family have asthma?

IF YES to “EVER?”: During the past 12 mo, has your child had an episode of asthma or an asthma attack?

IF YES to “EVER?”: Does your child still have asthma?

NHIS original and redesigned asthma questions

Asthma prevalence, 1980-96, asthma lifetime diagnosis, current and asthma attack prevalence, 1997-2002:

NHIS, children 0-17 years

0

20

40

60

80

100

120

140

1980 1985 1990 1995 2000

Pre

vale

nce

per

1,00

0 ch

ildre

n

Asthma prevalence (4.3% per yr )

Asthma lifetime diagnosis

Asthma attack prevalence

Current asthma prevalence

Other asthma indicators available from the NHIS

• 2002 asthma module– School days missed (trend established prior

to 1997)– Preventive medications– Given asthma management plan by doctor– Advised by doctor to change home

environment• 1999 asthma module (different questions)

– Wheezing severity– Use of OTC and prescription medications

Average number school days a child with asthma missed per year, ages 5-17 years:

NHIS 1980-2002

4.94.4 4.7

3.74.5

0.0

2.0

4.0

6.0

8.0

1980-82 1985-87 1990-92 1994-96 2002

Num

ber o

f day

s

NHIS redesign

*

•Per child with asthma having > one asthma attack per year

Indicators of asthma control among children with current asthma, 2002 NHIS

asthma module

Ever taken preventive medication

65%

Given management plan by MD

40%

Advised to change environment by MD

48%

Asthma hospitalizations

Asthma hospitalizations for children 0-17 years, 1980-2002 National Hospital

Discharge Survey (NHDS)

05

10152025303540

1980 1985 1990 1995 2000

Per 1

0,00

0 ch

ildre

n

Asthma mortality

Mortality component of National Vital Statistics System (NVSS)

Death certificate data received by NCHS from 50 States and DC can obtain State-level data

Coding system changed in 1999 from ICD-9 to ICD-10

Asthma deaths, children 0-17 years, 1980-2000, NVSS

0

1

2

3

4

5

1980 1985 1990 1995 2000

Per 1

,000

,000

chi

ldre

n

ICD-9

ICD-10

ICD-9

Race/ethnic disparities in the burden of childhood asthma

Healthy People 2010 overarching goal Examining disparities in asthma can guide

policy and program decisions However, issues in categorizing by race

New OMB guidelines: single vs. multiple race Ethnicity not consistently available in data

systems that rely on abstraction from medical records

Race/ethnic disparities in asthma attack prevalence, (1997-2001 annual average),

NHIS

0

2

4

6

8

10

12

14

Perc

ent c

hild

ren

Non-Hispanic

white

Non-Hispanic

black

Hispanic

Non-Hispanic black children

had 30% higher asthma attack

prevalence than NH white

children

Race/ethnic disparities in asthma attack prevalence, (1997-2001 annual average),

NHIS

0

2

4

6

8

10

12

14

Perc

ent c

hild

ren

Non-Hispanic

white

Non-Hispanic

black

Hispanic

Puerto Rican

Mexican

Racial disparities in asthma hospitalizations (2000-2002 annual

average), NHDS

0

10

20

30

40

50

60

70

Per 1

0,00

0 ch

ildre

n

White

Black

Black children had 240%

higher hospitalization rate than white

children

Race/ethnic disparities in mortality (1999-2001 annual average), NVSS

0

2

4

6

8

10

12

Per 1

,000

,000

chi

ldre

n Non-Hispanic black children

had 350% higher asthma death rate than

NH white children

Non-Hispanic

white

Non-Hispanic

black

Hispanic

Summary on trends in childhood asthma

Prevalence, health care use, and mortality increased through the mid 1990s

Since the mid 1990s, prevalence, ambulatory health care use, hospitalization and death rates have plateaued

Minority children bear a higher asthma burden Racial disparities are most pronounced for

preventable outcomes, such as ER visits, hospitalization and death

For additional information on asthma from the CDC

NCHS home page: http://www.cdc.gov/nchs/ Asthma Health E stat: asthma prevalence, health care

use and mortality for all ages in 2002 Summary statistics from the NHIS for children, 2002

National Center for Environmental Health: http://www.cdc.gov/nceh/airpollution/asthma/ Behavioral Risk Factor Surveillance Survey: state level

asthma prevalence for adults Links to asthma-related reports in the Morbidity and

Mortality Weekly Report, including the Asthma Surveillance Summary, 1980-1999