exposure to home and school environmental triggers and asthma morbidity in chicago inner-city...
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ORIGINAL ARTICLE LOWER AIRWAYS
Exposure to home and school environmental triggers andasthma morbidity in Chicago inner-city childrenElizabeth Banda1, Victoria Persky1, Gay Chisum2, Maureen Damitz2, Rhonda Williams2 & Mary Turyk1
1Division of Epidemiology and Biostatistics, University of Illinois at Chicago School of Public Health, Chicago, IL, USA; 2Respiratory Health
Association of Metropolitan Chicago, Chicago, IL, USA
To cite this article: Banda E, Persky V, Chisum G, Damitz M, Williams R, Turyk M. Exposure to home and school environmental triggers and asthma morbidity in
Chicago inner-city children. Pediatr Allergy Immunol 2013: 24: 734–741.
Keywords
asthma emergency department visit; asthma
hospitalization; asthma morbidity; indoor
asthma triggers; inner-city children; asthma
age groups
Correspondence
Elizabeth Banda, University of Illinois at
Chicago School of Public Health, 1603
W. Taylor, M/C 923, Chicago, IL 60612, USA
Tel.: 312-355-3974
Fax: 312-996-0064
E-mail: [email protected]
Accepted for publication 6 October 2013
DOI:10.1111/pai.12162
Abstract
Background: In children, asthma hospitalization rates are highest among those aged
0–4 yr, indicating more acute and/or severe asthma exacerbations in younger children.
We investigated the relationship between indoor exposures and three asthma
morbidity measures in children of different age groups (0–4, 5–11, and 12 yr of age
or older). Identifying the factors leading to asthma morbidity in specific subgroups
may lead to a better understanding of the disease and contribute to the development of
effective interventions tailored to subgroups.
Methods: Children between 0 and 18 yr of age with asthma were enrolled in an asthma
intervention program. At enrollment, hospitalizations, emergency room visits (ED),
asthma night symptoms, and exposure to conditions in the child’s home and school/
daycare related to indoor allergens were collected using standardized questionnaires.
Associations of exposure with the three asthma outcomes were estimated using logistic
regression, stratified by age group.
Results: Of 246 children enrolled, the youngest age group had more hospitalizations in
the past year, more ED visits in the past year, and more night awakenings in the past
month due to asthma than the oldest two age groups (p = 0.02; p < 0.0001; and
p = 0.01, respectively). Overall, more associations of exposures to home triggers were
found with hospitalization in children aged 0–11 yr, while classroom triggers were more
likely to be associated with hospitalizations among the oldest two groups, 5–18 yr of age.Conclusions: Examining the relationship of specific environmental exposures with
asthma exacerbations and hospitalizations across age group and in different indoor
environments warrants further study.
Asthma, the most common chronic disease in children in the
USA, affects 7.1 million children aged 0–17 yr, approximately
one-third of all asthmatics in the USA (1). Differences in
asthma prevalence and morbidity exist among population
subgroups, which are often explained by variation in social,
economic and environmental factors. In children, asthma
hospitalization rates are highest in the age group 0–4 yr (2)
indicating more severe asthma exacerbations among younger
children.
While causes for asthma exacerbations and hospitalizations
are well documented, variations in risk across age group are
less understood. Studies have identified viral infections as
major triggers of asthma exacerbations and hospitalizations in
children and adults (3–5). Similarly, a large body of evidence
suggests that exposure to indoor pollutants (such as second
hand smoke) and indoor allergens (such as dust mite, cat, dog,
mouse, cockroach, and molds) play an important role in the
exacerbation of asthma (6, 7) in children (8–10) and adults (11).
Relationships in some studies are stronger in children with
specific allergies to the exposures (9, 10). Other studies that do
not include allergy testing have found associations with
dampness (12), cockroach allergen (8), and wall integrity
(11). Identifying factors leading to asthma morbidity in specific
subgroups is important, as it may lead to a better understand-
ing of the disease, its risk factors, and the development of
effective interventions tailored to subgroups, which may
subsequently result in better asthma outcomes.
Intervention studies have shown improved asthma control
with modification of the home environment. Some have
demonstrated that advice by physicians (13) as well as case-
management by trained social workers (14) and research
assistants focused on modification of the home environment
(15) can reduce asthma symptoms in children. Other studies
showed improved measures of control with intensive home visit
734 Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Pediatric Allergy and Immunology
intervention by community health workers (16) and with
integrating home visits by community educators with clinic-
based education (17, 18), public housing education (19), home
remediation (20), school screening (21), and community-based
healthcare providers (22, 23).
Few of the above-mentioned studies were able to delineate
effects of specific indoor exposures and those that were able
to examine specific exposures did not yield consistent results
(8, 10–12, 24). A home-based intervention by community
educators in a predominantly African American low-income
Chicago neighborhood with detailed visual assessments
provides a unique opportunity to examine associations of
specific indoor home and school environmental exposures with
measures of asthma morbidity across age groups.
Methods
Study population
The data for this analysis come from a cohort of 246 children
from 158 families enrolled in an asthma intervention project
aimed at improving asthma control in children residing in the
Englewood and West Englewood communities on the South-
side of Chicago. In 2005, the asthma hospitalization rate was
44/10,000 for children aged 2–17 yr living in Englewood, and
21/10,000 for children aged 2–17 yr living in the rest of
Chicago (personal communication, Rich Forshee, Illinois
Department of Public Health). Data collected from an addi-
tional 87 children from 59 families from one of the community
health educators (CHEs) were deemed unreliable and excluded.
Another group of 54 children from 36 families was not
included because they did not complete a home assessment.
Children enrolled were referred to the program from a variety
of sources, predominantly healthcare providers and school
screenings. Enrollment into the program occurred between
January 2006 and November 2008. All children were 0–18 yr of
age with a physician’s diagnosis of asthma as reported by the
caregiver. Evaluation of this program was approved by the
University of Illinois at Chicago Office for the Protection of
Research Subjects. The present study is a cross-sectional
analysis of exposures and level of asthma morbidity at baseline.
Data collection
Data used in our analysis were collected by two CHEs working
for the Respiratory Health Association of Metropolitan
Chicago: one a registered nurse, the second with a bachelor
of science degree. At enrollment, caregivers were surveyed by
the CHE regarding their child’s asthma symptoms, healthcare
utilization, asthma history and daycare/school triggers.
Approximately one month later, the CHE performed a home
assessment that consisted of surveying participants regarding
their home environment and performing a home walkthrough
recording the presence of asthma triggers and home conditions.
Exposures were evaluated using a modified version of the
Coover tool, a home assessment form developed by an asthma
nurse and used for inspection of the home environment in two
previous asthma studies (25, 26). CHEs were trained on how to
complete the home assessment and shadowed by a field
supervisor during their first home inspections to ensure that
assessments were completed correctly.
Three parentally reported asthma morbidity measures were
selected for analysis: any hospitalization in the last 12 months,
any emergency department (ED) visit in the last 12 months and
>2 night awakenings in the past month due to asthma
symptoms. Asthma-related environmental home conditions
and parentally-reported classroom triggers were selected for
analysis. Environmental factors known to be common asthma
triggers (based on the literature) and additional factors
suspected to contribute to asthma exacerbations were deter-
mined by self-report and visual inspection including smoke in
the home, dampness, mold, holes in the walls, cockroaches,
rodents, furry/feathered pets, plants, wall-to-wall carpeting
anywhere in the home, wall-to-wall carpeting in the child’s
sleeping area, clutter in the child’s sleeping area, dusty/dirty
surfaces, peeling wallpaper/flaking paint, >2 people per bed-
room, furry pets in the bedroom, renting home, and eating in
the bedroom. Classroom triggers included plants/aquariums
and carpet. A number of other classroom triggers (pets, mold/
mildew, roaches, water damage, rodents, smokers, presence of
wood stove or fireplace) were evaluated but not selected for
further analysis because they were reported infrequently. For
children ≤4 not in daycare (20/58), classroom trigger exposures
were counted as zero. Three variables were created from the
individual environmental factors: sum of home triggers, sum of
child’s bedroom triggers and none vs. any classroom triggers
(see Table 2 for details). Because previously published findings
report varying asthma hospitalization rates among pediatric
age groups in the USA, children were stratified into three age
groups: 0–4 yr of age, 5–11 yr of age, and 12 yr of age and
older (2).
Statistical methods
Univariate associations of symptoms and triggers across age
were assessed by chi-square tests. We used multivariable
logistic regression models with a random intercept to account
for clustering of children within families (SAS PROC GEN-
MOD) to study associations between individual environmental
factors and the three dichotomous asthma morbidity measures
at baseline. We examined hospitalizations, ED visits and night
awakenings by age group controlling for sex, with additional
control for seasonality in night awakenings. Seasons were
defined as fall (September–October), winter (November–March), spring (April–May), and summer (June–August). All
analyses of children age 0-4 yr were adjusted for daycare
attendance. All analyses were performed using SAS 9.2
manufactured by SAS Institute Inc., Cary, North Carolina,
USA.
Results
Of the 246 children enrolled in the program, 24% were aged
0–4, 48% were 5–11 and 28% were ≥12 yr old; 16% had been
hospitalized in the past year, 46% visited an ED in the past
year and 37% awakened at night >2 times in the past month
Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 735
Banda et al. Indoor triggers and asthma morbidity
due to asthma symptoms (Table 1). Significant differences were
found in asthma characteristics across age groups, with
decreasing frequency of number of children hospitalized,
visiting the ED, and awakening at night as age increased.
There were no statistically significant differences in asthma
management characteristics across groups other than caregiv-
ers’ ability to manage their children’s asthma based on CHE’s
assessment (Table 1). Caregivers with children ≥12 yr of age
tended to be the most capable of managing their child’s asthma
and those with children aged 0–4 yr the least capable. Having
more than one child with asthma did not significantly affect
caregiver’s ability to manage their children’s asthma (not
shown). Contrary to a USA sample of children with asthma
(27), a high percent of children were on medication: 90% on
reliever medication and 44% on controller medication.
With respect to environmental characteristics (Table 2), the
most common environmental exposures were living in a home
with holes in the walls or floors, mold, wall-to-wall carpeting,
clutter in the bedroom, dust/dirty surfaces, and >2 people per
bedroom. Classroom triggers more often reported were plants/
aquariums (10%) and carpet (14%). Among participants, 24%
were exposed to at least one school trigger (Table 2).
Analysis by age group
Exposure to some individual home environmental triggers
differed statistically across age group. Overall, children aged
0–4 yr tended to have lower levels of exposure than older age
groups (Table 2). Differences in exposure to classroom triggers
were not found.
In all children, hospitalizations were associated with holes in
the wall, the sum of home triggers, and plants/aquariums and
carpet in the classroom (Table 3). More significant associations
were apparent in the younger two age groups, compared with
those ≥12 yr old, although specific triggers differed across age
group. In the youngest age group, exposure to dampness,
mold, holes in the wall, cockroaches, rodents, number of home
exposures, and plants/aquarium in the classroom were signif-
icantly associated with hospitalization. For children aged 5–11,carpet in the bedroom, >2 people in the bedroom, plants/
aquariums and carpet in the classroom were positively asso-
ciated, while plants and sum of bedroom triggers were inversely
associated, with hospitalizations. For those ≥12 yr old, holes in
the wall, plants/aquarium in the classroom, and carpet in the
classroom were positively associated with hospitalizations.
Far fewer significant associations were seen with ED visits
than with hospitalizations, with most of the associations
occurring among the older two age groups and only carpet in
the classroom being associated with ED visits among all
children (Table 4). ED visits were significantly associated with
> 2 people per bedroom, carpet in the classroom, and plants in
the home (last variable inversely associated) in children aged
5–11 and with sum of home triggers in children ≥12 yr old.
Among all children, night symptoms were significantly
associated with holes in the walls, cockroaches, ≥1 classroom
condition, and carpet in the classroom (Table 5). Across age
group, night symptoms were significantly inversely associated
with dampness in the home and positively associated with ≥1classroom trigger and carpet in the classroom in children aged
5–11 yr, while inversely associated with carpet in the house and
positively associated with plants/aquariums in the classroom in
children age ≥12 yr.
Discussion
Overall, this study finds more associations of exposures to
home triggers with hospitalization in younger children aged
0–11 yr than those aged12–18 yr.These findingsmaybepartially
Table 1 Asthma characteristics by age group (n = 246)
All ages (n = 246) Ages 0–4 (n = 58) Ages 5–11 (n = 118) Ages ≥12 (n = 70)Chi-square
p-value% Reported % Reported % Reported % Reported
Asthma characteristics
Hospitalized in the past year 16 28 13 11 0.02
Emergency room visit
in the past year
46 71 43 29 <0.0001
Night awakenings 37 49 39 24 0.01
Asthma management
On reliever medication 90 95 91 87 0.31
On controller medication 44 45 47 39 0.49
Never miss medication* 35 44 33 30
Sometimes miss medication* 50 44 55 44 0.44
Often miss medication* 16 12 13 26
Reliever + control vs.
Reliever only†
48 48 50 42 0.55
Ability to manage asthma‡ 62 48 62 74 0.01
*Percentages based on 107 children on controller medication.
†Based on a sample size of 221 children on medication.
‡Based on the CHE’s evaluation using the Asthma Ability Form.
Values in bold are statistically significant, p< .05.
736 Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Indoor triggers and asthma morbidity Banda et al.
explained by their potentially spending a greater proportion of
time at home. In a recent study of USA children, those of
preschool age were shown to spend less time outdoors
than previous generations (28). Associations with dampness,
Table 2 Environmental characteristics by age group (n = 246)
Environmental factors
All ages (n = 246) Ages 0–4 (n = 58) Ages 5–11 (n = 118) Ages ≥12 (n = 70)Chi-square
p-value% Exposed % Exposed % Exposed % Exposed
Home triggers*
Smoke 39 38 42 34 0.54
Dampness‡ 31 26 31 36 0.49
Mold 49 41 46 61 0.05
Holes§ 40 40 39 42 0.92
Cockroaches 20 21 20 17 0.84
Rodents 30 22 31 36 0.26
Furry pets 30 22 32 31 0.37
Plants 26 16 34 21 0.02
Carpet anywhere in home 51 59 52 44 0.27
Carpet in bedroom 40 47 39 37 0.52
Clutter in bedroom 69 64 66 77 0.19
Dusty/dirty surfaces 61 72 56 61 0.11
Peeling wallpaper/flaking paint¶ 31 17 38 31 0.02
>2 people per bedroom 44 51 41 43 0.48
Pet sleeps in bedroom 7 9 5 9 0.56
Rents 53 66 50 49 0.10
Eating in bedroom 29 33 28 30 0.73
Sum of home triggers**
0–3 31 36 31 26
4–5 31 40 25 36 0.07
>6 38 24 44 39
Sum of bedroom triggers††
0 11 16 10 10
1 24 16 30 20
2 24 26 24 23 0.38
3 21 21 15 31
≥4 20 22 21 16
Classroom triggers‡‡
Pets 3 3 4 0 0.30†
Plants/aquariums 10 7 14 6 0.13
Mold/mildew 3 0 4 1 0.17†
Roaches 2 0 3 3 0.43†
Carpet 14 16 17 7 0.19
Water damage 2 0 4 1 0.28†
Rodents 6 2 7 9 0.23†
Smokers 4 3 4 4 0.94†
Sum of school triggers dichotomized§§
0 76 79 70 84 0.08
≥1 24 21 30 16
*Percentages based on sample sizes of 241–246.
†Indicates 33% or 50% of cells have count <5; chi-square may not be valid test.
‡Dampness: signs of leaks in ceilings or walls and/or signs of water leaks in the bathroom, kitchen or any other room with water.
§Holes: Holes in the walls or floors and/or space between the wall and baseboard.
¶Also includes falling plaster anywhere in the home.
**Sum of home triggers: smoke, holes, dampness, mold, carpeting anywhere in the home, plants, furry pets, cockroaches, rodents, clutter in
the bedroom, and peeling wallpaper/flaking paint.
††Sum of bedroom triggers: clutter, food eaten in child’s bedroom area, live plants, wall-to-wall carpet, dusty/dirty surfaces, peeling wallpaper/
flaking paint, and holes.
‡‡Based on a sample size of 237.
§§Sum of school triggers: pets, plants/aquariums, mold/mildew, roaches, carpet, water damage, rodents, and smokers.
Values in bold are statistically significant, p< .05.
Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 737
Banda et al. Indoor triggers and asthma morbidity
cockroaches, and rodents are consistent with findings from
previous studies (8–10, 12). In age-stratified analyses,more home
triggers were found to be associated with asthma hospitalization
in the youngest two age groups, whereas classroom triggers were
associated in the older two age groups indicating the importance
of targeting areas or spaces highly used by children when
performing environmental interventions. This is supported by
previous studies demonstrating reductions in levels of cockroach
allergen and dust mite allergens in the bedroom as being
significantly correlatedwith a decrease in asthmamorbidity (15).
When associations of individual environmental factors with
other morbidity measures (ED visits and night symptoms) were
examined, fewer factors appeared to be significant. The lack of
association between environmental factors and ED visits is not
surprising as ED visits are not necessarily indicative of asthma
severity for our population. Our study population makes high
use of the ED as demonstrated by the number of children
visiting the emergency room in the past year (46%); frequently,
at baseline the ED was used as the regular care office for the
child’s asthma.
A new finding in our study was the association between
individual classroom triggers and hospitalizations, ED visits
and night symptoms, predominantly in children aged 5 yr and
older. Only two factors were analyzed individually (plants
and/or aquarium and carpet) because they were more
prevalent (roughly 10% of children were exposed to each of
Table 3 Associations of indoor environmental triggers with asthma hospitalizations in the past year by age group* (n = 246)
Environmental factors
All ages (n = 246) Ages 0–4† (n = 58) Ages 5–11 (n = 118) Ages ≥12 (n = 70)
OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI)
Home triggers‡
Smoke 0.58 (0.21, 1.59) 1.36 (0.39, 4.80) 0.39 (0.08, 1.81) 0.21 (0.02, 1.86)
Dampness 1.07 (0.44, 2.60) 5.35 (1.27, 22.46) 0.32 (0.07, 1.50) 1.11 (0.18, 6.91)
Mold 2.36 (0.95, 5.85) 4.14 (1.19, 14.45) 2.62 (0.72, 9.58) 2.06 (0.32, 13.41)
Holes 3.02 (1.20, 7.56) 3.60 (1.06,12.21) 1.63 (0.41, 6.55) 12.43 (1.35, 114.24)
Cockroaches 1.10 (0.44, 2.73) 5.92 (1.34, 26.20) 0.56 (0.11, 2.87) NE§
Rodents 2.25 (0.77, 6.53) 7.39 (1.68, 32.58) 1.50 (0.33, 6.87) 3.50 (0.58, 21.10)
Furry pets 0.89 (0.37, 2.15) 1.32 (0.31, 5.51) 0.69 (0.18, 2.70) 1.35 (0.23, 7.88)
Plants 0.59 (0.23, 1.51) 3.24 (0.62, 16.86) 0.12 (0.01, 0.98) 1.26 (0.20, 8.09)
Carpet anywhere in home 0.54 (0.22, 1.36) 0.78 (0.23, 2.63) 0.30 (0.08, 1.10) 0.38 (0.06, 2.33)
Carpet in bedroom 2.21 (0.88, 5.54) 0.81 (0.24, 2.66) 10.95 (1.43, 84.00) 4.80 (0.47, 49.27)
Clutter in bedroom 1.64 (0.62, 4.32) 6.83 (0.93, 49.96) 1.05 (0.28, 4.00) 0.87 (0.13, 5.89)
Dusty/dirty surfaces 1.27 (0.33, 4.87) 3.79 (0.68, 21.15) 0.90 (0.22, 3.64) 0.57 (0.08, 3.94)
Peeling wallpaper/flaking paint 1.58 (0.46, 5.45) 1.29 (0.27, 6.13) 2.10 (0.51, 8.55) 2.94 (0.40, 21.59)
>2 people per bedroom 2.21 (0.87, 5.64) 1.11 (0.32, 3.82) 7.48 (1.87, 29.91) 0.77 (0.08, 7.50)
Pet sleeps in bedroom 1.60 (0.51, 5.03) 5.00 (0.66, 37.93) 1.27 (0.12, 13.10) NE§
Rents 1.13 (0.44, 2.87) 0.43 (0.11, 1.66) 1.56 (0.43, 5.63) 1.07 (0.16, 7.08)
Eating in bedroom 1.84 (0.73, 4.66) 2.79 (0.84, 9.27) 0.94 (0.25, 3.52) 2.62 (0.38, 17.94)
Sum of home triggers
0–3 Reference Reference Reference Reference
4–5 5.75 (1.71, 19.32) 11.01 (1.06, 114.00) 3.15 (0.67, 14.88) NE§
≥6 2.16 (0.77, 6.07) 52.42 (3.74, 735.62) 0.51 (0.11, 2.29) NE§
p for trend 0.23 0.001 0.25 0.98
Sum of bedroom triggers
0 Reference Reference Reference Reference
1 1.07 (0.17, 6.67) 2.01 (0.12, 34.51) 0.32 (0.05, 2.15) NE§
2 0.51 (0.14, 1.90) 1.79 (0.13, 23.79) 0.15 (0.02, 0.94) NE§
3 1.06 (0.30, 3.78) 3.75 (0.29, 48.32) 0.38 (0.07, 2.06) NE§
≥4 0.77 (0.20, 2.98) 6.98 (0.58, 83.51) 0.08 (0.01, 0.69) NE§
p for trend 0.79 0.07 0.08 0.39
Classroom triggers¶
≥1 vs. 0 triggers 2.07 (0.57, 7.47) 1.70 (0.35, 8.28) 2.19 (0.54, 8.91) 4.87 (0.49, 48.65)
Plants/aquariums 7.05 (1.49, 33.40) 19.06 (1.56, 232.31) 5.71 (1.05, 30.90) 48.39 (2.57, 910.50)
Carpet 4.69 (1.41, 15.66) 3.43 (0.60, 19.61) 4.27 (1.21, 15.00) 21.67 (1.62, 289.16)
*Odds ratios adjusted for sex and clustering of children in families.
†Adjusted for daycare.
‡Based on sample sizes of 241–246.
§Could not be estimated.
¶Based on sample size of 237.
Values in bold are statistically significant.
738 Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Indoor triggers and asthma morbidity Banda et al.
these factors). Having one or more trigger in the classroom
increased the likelihood of children aged 5–11 yr to experience
disturbed sleep. Having plants and/or aquariums in the
classroom increased the likelihood of children in all age
groups to be hospitalized and children ≥12 yr old to have
disturbed sleep. Carpeting in the classroom was also associ-
ated with all three asthma outcomes among children aged
5–11 and with hospitalizations among those ≥12 yr of age.
These findings suggest that environmental asthma interven-
tions should not only focus in the home, but also in schools,
which have been identified as a major source of allergen
exposure that could possibly contribute to disease exacerba-
tion and where children spend a large amount of time (24).
Recent scientific literature includes few studies evaluating the
relationship between asthma outcomes and indoor allergen
exposures in schools and daycare environments (29). More
research in this area is needed.
Our findings have several limitations. First, the design of this
investigation was cross-sectional. Thus, no temporal relation-
ship between indoor exposures and asthma could be estab-
lished. Second, outcomes were determined by parental report
rather than through symptom diaries or by review of medical
records. Bias in reporting of night awakenings may differ by
age group, as parents may be more aware of sleep disturbances
Table 4 Associations of indoor environmental triggers with ED visits in the past year by age group* (n = 246)
Environmental factors
All ages (n = 246) Ages 0–4† (n = 58) Ages 5–11 (n = 118) Ages ≥12 (n = 70)
OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI)
Home triggers‡
Smoke 0.89 (0.50, 1.62) 0.82 (0.26, 2.59) 1.11 (0.50, 2.42) 0.44 (0.15, 1.30)
Dampness 0.99 (0.52, 1.87) 3.80 (0.67, 21.72) 0.68 (0.29, 1.57) 1.41 (0.46, 4.28)
Mold 0.92 (0.51, 1.67) 1.01 (0.29, 3.54) 0.79 (0.36, 1.74) 2.51 (0.80, 7.90)
Holes 0.95 (0.50, 1.77) 0.44 (0.12, 1.58) 0.88 (0.39, 1.99) 2.13 (0.70, 6.49)
Cockroaches 1.27 (0.63, 2.55) 0.79 (0.20, 3.17) 2.14 (0.87, 5.30) 0.44 (0.09, 2.08)
Rodents 0.91 (0.45, 1.84) 0.57 (0.15, 2.17) 1.13 (0.48, 2.65) 1.30 (0.39, 4.33)
Furry pets 0.88 (0.48, 1.64) 0.93 (0.22, 3.98) 0.87 (0.38, 1.95) 1.22 (0.39, 3.82)
Plants 0.59 (0.32, 1.08) 1.62 (0.27, 9.70) 0.29 (0.12, 0.67) 1.98 (0.67, 5.85)
Carpet anywhere in home 0.75 (0.42, 1.35) 1.39 (0.41, 4.65) 0.47 (0.22, 1.02) 0.59 (0.20, 1.80)
Carpet in bedroom 1.42 (0.78, 2.59) 1.02 (0.31, 3.33) 2.09 (0.95, 4.60) 1.61 (0.52, 5.03)
Clutter in bedroom 1.17 (0.64, 2.14) 1.35 (0.43, 4.27) 1.07 (0.49, 2.33) 3.45 (0.68, 17.47)
Dusty/dirty surfaces 1.14 (0.60, 2.17) 1.12 (0.24, 5.11) 1.08 (0.50, 2.35) 0.85 (0.25, 2.90)
Peeling wallpaper/flaking paint 0.70 (0.32, 1.49) 0.55 (0.11, 2.69) 0.70 (0.30, 1.65) 1.53 (0.39, 6.04)
>2 people per bedroom 1.56 (0.84, 2.87) 0.31 (0.09, 1.06) 3.10 (1.38, 6.98) 1.46 (0.46, 4.63)
Pet sleeps in bedroom 0.78 (0.25, 2.46) 0.59 (0.09, 4.07) 1.17 (0.17, 8.29) 0.44 (0.04, 4.49)
Rents 1.07 (0.60, 1.92) 0.25 (0.05, 1.20) 1.38 (0.65, 2.93) 0.83 (0.26, 2.60)
Eating in bedroom 1.24 (0.65, 2.39) 2.76 (0.68, 11.16) 0.56 (0.23, 1.37) 2.65 (0.83, 8.45)
Sum of home triggers
0–3 Reference Reference Reference Reference
4–5 1.94 (0.92, 4.10) 1.42 (0.34, 5.97) 1.26 (0.46, 3.48) 19.06 (2.17, 167.13)
≥6 0.84 (0.44, 1.61) 1.26 (0.29, 5.56) 0.69 (0.29, 1.61) 4.94 (0.57, 43.18)
p for trend 0.51 0.72 0.35 0.31
Sum of bedroom triggers
0 Reference Reference Reference Reference
1 0.81 (0.26, 2.47) 0.22 (0.02, 2.10) 0.57 (0.15, 2.12) NE§
2 0.83 (0.32, 2.18) 0.55 (0.07, 4.13) 0.72 (0.20, 2.51) NE§
3 0.77 (0.29, 2.07) 0.54 (0.06, 4.53) 0.41 (0.09, 1.84) NE§
4 0.82 (0.27, 2.43) 3.41 (0.28, 41.77) 0.27 (0.07, 1.04) NE§
p for trend 0.78 0.17 0.06 NE
Classroom triggers¶
≥1 vs. 0 triggers 1.43 (0.65, 3.14) 1.33 (0.31, 5.72) 1.65 (0.69, 3.94) 1.03 (0.12, 9.02)
Plants/aquariums 2.12 (0.56, 7.97) 1.29 (0.12, 14.24) 1.68 (0.45, 6.24) 10.60 (0.65, 171.91)
Carpet 3.82 (1.49, 9.78) 4.26 (0.43, 42.73) 3.41 (1.19, 9.75) 4.81 (0.39, 58.59)
*Odds ratios adjusted for sex and clustering of children in families.
†Adjusted for daycare.
‡Based on sample sizes of 241–246.
§Could not be estimated.
¶Based on a sample size of 237.
Values in bold are statistically significant.
Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 739
Banda et al. Indoor triggers and asthma morbidity
in younger children and children were not always present at
interviews. Parental underreporting of their children’s asthma
symptoms and asthma triggers has been documented (30). The
presence of classroom triggers was also not confirmed. Use of
multiple school rooms and probably different exposures among
rooms in children ≥12 yr of age could not be accounted for,
decreasing the precision of our exposure estimates. Third, other
etiologic factors of asthma that could be confounders were not
assessed including history of viral infection (although correct-
ing for seasonality might have partially controlled for the
effects of viral infection on night symptoms) and atopic
allergies. Fourth, our small sample size yielded estimates with
wide confidence intervals underscoring the importance of
future studies with larger sample sizes.
Examining the age–specific relationships of environmental
exposures with asthma exacerbations and hospitalizations
warrants further study. Despite these limitations, our findings
highlight the importance of assessing exposure to classroom, as
well as home environmental triggers. If confirmed by other
studies, differences seen among age groups could support
specific intervention strategies aimed at decreasing asthma
morbidity in high-risk populations.
Acknowledgments
We would like to acknowledge the Englewood and West
Englewood communities for their participation, and the many
community andmedical partners thatmade this project possible.
Table 5 Associations of indoor environmental triggers with >2 asthma night awakenings in the past month by age group* (n = 246)
Environmental factors
All ages (n = 246) Ages 0–4† (n = 58) Ages 5–11 (n = 118) Ages ≥12 (n = 70)
OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI)
Home triggers‡
Smoke 1.49 (0.76, 2.95) 0.92 (0.29, 2.90) 2.13 (0.84, 5.42) 1.03 (0.30, 3.53)
Dampness 0.50 (0.25, 1.03) 2.49 (0.65, 9.51) 0.27 (0.10, 0.75) 0.51 (0.13, 1.92)
Mold 0.68 (0.34, 1.37) 1.00 (0.31, 3.21) 0.67 (0.29, 1.56) 0.77 (0.19, 3.16)
Holes 2.29 (1.18, 4.44) 3.17 (0.95, 10.52) 2.35 (0.97, 5.67) 3.22 (0.92 11.32)
Cockroaches 2.32 (1.15, 4.68) 4.00 (0.83, 19.25) 1.99 (0.73, 5.37) 2.31 (0.68, 7.83)
Rodents 1.18 (0.54, 2.61) 0.56 (0.12, 2.56) 2.27 (0.87, 5.89) 1.04 (0.24, 4.47)
Furry pets 1.45 (0.73, 2.90) 2.26 (0.55, 9.26) 1.58 (0.64, 3.90) 0.98 (0.31, 3.08)
Plants 1.02 (0.52, 2.02) 0.68 (0.14, 3.33) 1.11 (0.46, 2.64) 0.99 (0.25, 3.92)
Carpet anywhere in home 0.64 (0.33, 1.22) 1.26 (0.40, 4.01) 0.57 (0.25, 1.34) 0.16 (0.04, 0.64)
Carpet in bedroom 1.51 (0.77, 2.96) 0.71 (0.24, 2.13) 2.14 (0.87, 5.27) 3.26 (0.80, 13.34)
Clutter in bedroom 1.09 (0.56, 2.10) 0.72 (0.25, 2.06) 1.25 (0.53, 2.98) 2.35 (0.45, 12.35)
Dusty/dirty surfaces 1.28 (0.61, 2.71) 1.79 (0.50, 6.45) 0.98 (0.41, 2.34) 1.44 (0.31, 6.75)
Peeling wallpaper/flaking paint 1.20 (0.55, 2.62) 0.67 (0.16, 2.83) 1.70 (0.71, 4.08) 1.82 (0.39, 8.42)
>2 people per bedroom 1.46 (0.75, 2.83) 0.62 (0.20, 1.91) 2.19 (0.92, 5.23) 1.14 (0.27, 4.75)
Pet sleeps in bedroom 0.96 (0.25, 3.68) 0.63 (0.08, 5.04) 2.05 (0.35, 11.92) 0.42 (0.04, 4.28)
Rents 1.21 (0.64, 2.29) 0.96 (0.28, 3.27) 1.58 (0.69, 3.61) 0.78 (0.21, 2.83)
Eating in bedroom 0.73 (0.35, 1.52) 0.71 (0.22, 2.31) 0.50 (0.17, 1.47) 1.89 (0.37, 9.77)
Sum of home triggers
0–3 Reference Reference Reference Reference
4–5 2.13 (0.92, 4.91) 2.12 (0.63, 7.12) 1.65 (0.52, 5.28) 4.67 (0.71, 30.88)
≥6 1.34 (0.64, 2.78) 2.14 (0.46, 9.94) 1.42 (0.55, 3.63) 1.31 (0.18, 9.57)
p for trend 0.50 0.27 0.50 0.87
Sum of bedroom triggers
0 Reference Reference Reference Reference
1 1.45 (0.51, 4.13) 4.13 (0.49, 34.99) 0.76 (0.19, 3.01) 3.03 (0.19, 47.59)
2 1.14 (0.45, 2.90) 3.62 (0.66, 19.83) 0.55 (0.14, 2.17) 1.07 (0.08, 14.79)
3 1.18 (0.47, 2.97) 2.46 (0.43, 14.17) 1.47 (0.34, 6.35) 1.06 (0.10, 10.76)
≥4 0.58 (0.18, 1.81) 0.92 (0.16, 5.46) 0.25 (0.04, 1.50) 1.80 (0.14, 23.26)
p for trend 0.21 0.57 0.20 0.76
Classroom triggers§
≥1 vs. 0 triggers 2.40 (1.06, 5.43) 1.05 (0.31, 3.59) 3.08 (1.13, 8.44) 4.39 (0.74, 25.97)
Plants/aquariums 2.33 (0.56, 9.68) 0.92 (0.10, 8.59) 2.03 (0.48, 8.57) 32.15 (1.28, 807.54)
Carpet 3.36 (1.22, 9.24) 1.33 (0.32, 5.54) 3.65 (1.20, 11.13) 11.12 (0.58, 212.00)
*Odds ratios adjusted for sex, season, and clustering of children in families.
†Adjusted for daycare.
‡Based on sample sizes of 238–243.
§Based on a sample size of 235 children.
Values in bold are statistically significant.
740 Pediatric Allergy and Immunology 24 (2013) 734–741 ª 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Indoor triggers and asthma morbidity Banda et al.
Funding
Funding for this project included grants from the Merck
Childhood Asthma Network, Inc. (MCAN) funded by the
MerckCompanyFoundation and theLloydA.FryFoundation.
Conflict of Interest
No conflict of interest declared.
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