Assessment of Asthma Control Questionnaire as a Metric for Children’s Traffic Air Pollution Exposures at Two Roadside El Paso Elementary Schools

Amit U. Raysoni, Ph.D., M.P.H., UTRGVSoyoung Jeon, Ph.D., UTEP

Juan Aguilera, M.D., M.P.H., UTEPWen-Whai Li, Ph.D., P.E., UTEP

Session 2: Schools, Childhood Asthma, and Interventions

Transportation, Air Quality, and Health Symposium, Austin, TX

February 19, 2019

Introduction

• Traffic air pollution and its associated pulmonary health effects have garnered a lot of attention in the scientific community especially in sensitive populations such as young elementary school children.

• The border city of El Paso, TX is impacted by high traffic emissions due to busy U.S.-Mexico port of entries, and high vehicular traffic on interstate highways crisscrossing the length and breadth of this arid high elevation city.

• As part of a traffic air pollution and health effects study, continuous monitoring of PM2.5, NO2, and O3 were conducted at two elementary schools adjoining a major interstate highway and asthmatic students were selected for a panel based longitudinal study in fall 2017.

• Various health measurements assessing pulmonary health of the study subjects were administered during the course of the study.

Study Design & Methods• 23 children (ages 6-12 years) days

over 9 weeks in late Fall 2017.

• Assessments included • exhaled nitric oxide (eNO, marker of

airway inflammation), • lung function [forced vital capacity

(FVC) and forced expiratory volume in one second (FEV1)], and

• asthma symptoms and control questionnaires (ACQ)

• Continuous measurements of O3, NO2, and PM2.5 were conducted concurrently outside the two schools (Schools B & CW) and a residential site (Site H) in close proximity to the schools.

Asthma Control Questionnaire (ACQ)

• This study assesses the validity of asthma control questionnaires (ACQ) for understanding children’s exposure to air pollution.

• The Asthma Control Questionnaire (ACQ) is a 7-item questionnaire.

• It is used to measure the adequacy of asthma control both in clinical research studies and in clinical practice.

ACQ

• The ACQ includes items on

• specific symptoms,

• timing of symptoms, (4 questions)

• activity limitation, (1 question)

• use of rescue medications (1 question), and

• lung function (1 question) – FEV1% Predicted.

Significance of ACQ

• As per the international guidelines, in order to achieve good asthma control it is necessary that the treatment should minimize day and night time symptoms, activity limitation, airway narrowing, and rescue bronchodilator use and thus reduce the risk of life-threatening exacerbations and long-term morbidity ( Juniper, 2005).

• It was initially developed for adults (Juniper et al., 1999) but has been subsequently validated for use among children 6-16 years of age (Juniper et al., 2010).

Usage of ACQ in the Context of Air Quality Study

• Very few studies have used these ACQ scores to assess children’s exposure to traffic air pollutants.

• The research work analyzes the questionnaires to understand the role of traffic air pollutants and medicinal usage and its success thereof in controlling asthma in a majority Mexican-American student cohort.

• Usage of ACQ in the context of air pollution studies could help reflect clinically measurable and biologically relevant changes in lung function and asthma symptoms that result from poor air quality and could increase our understanding of how air pollution influences asthma exacerbation.

Asthma Control Questionnaire - Criteria

• Individual question scores on the ACQ are scaled from 0 to 6 based on severity of symptoms.

• Overall score is the mean of the 7 questions.

• Therefore, the minimum overall ACQ score is 0.0 for well-controlled asthma and the maximum score is 6.0 for poorly-controlled asthma.

• The lowest clinically relevant score for the ACQ among asthmatic children has been shown to be 0.53 ± 0.45 (Juniper et al., 2010).

• A score of 1.5 on the ACQ has been identified as the best discriminator between asthma patients that are ‘well-controlled’ and ‘not well-controlled’.

Asthma Control Questionnaire• 1. On average, during the past week, how often were you woken by your asthma during the night?

0 Never

1 Hardly ever

2 A few minutes

3 Several times

4 Many times

5 A great many times

6 Unable to sleep because of asthma

• 2. On average, during the past week, how bad were your asthma symptoms when you woke up in the morning?

0 No symptoms

1 Very mild symptoms

2 Mild symptoms

3 Moderate symptoms

4 Quite severe symptoms

5 Severe symptoms

6 Very severe symptoms

Asthma Control Questionnaire….• 3. In general, during the past week, how limited were you in your activities because

of your asthma?• 0 Not limited at all • 1 Very slightly limited • 2 Slightly limited • 3 Moderately limited • 4 Very limited • 5 Extremely limited • 6 Totally limited

• 4. In general, during the past week, how much shortness of breath did you experience because of you asthma?

0 None

• 1 A very little • 2 A little • 3 A moderate amount • 4 Quite a lot • 5 A great deal • 6 A very great deal

Asthma Control Questionnaires…• 5. In general, during the past week, how much of the time did you wheeze?

• 0 Not at all

• 1 Hardly any of the time

• 2 A little of the time

• 3 A moderate amount of the time

• 4 A lot of the time

• 5 Most of the time

• 6 All the time

• 6. On average, during the past week, how many puffs of short-acting bronchodilator (eg. Ventolin) have you used each day?• 0 None

• 1 1±2 puffs most days

• 2 3±4 puffs most days

• 3 5±8 puffs most days

• 4 9±12 puffs most days

• 5 13±16 puffs most days

• 6 More than 16 puffs most days

• 7. FEV1 %

• 0 >95% predicted

• 1 95±90%

• 2 89±80%

• 3 79±70%

• 4 69±60%

• 5 59±50%

• 6 <50% predicted

Study Subject Characteristics

Results from the 2017 CAR TEEH Study

School CW

• 199 ACQ completed

• 16-17 repeated measures per subject

• Mean ACQ score for the study: 0.52 ± 0.51

• Minimum: 0.0

• Maximum: 2.71

School FB

• 165 ACQ completed

• 13-16 repeated measures per subject

• Mean ACQ score for the study: 1.00 ± 0.64

• Minimum: 0.0

• Maximum: 3.0

Average ACQ Score Box plots

Data from School CW • 12 subjects in the study cohort

• 5 Females, 7 Males

0

0.2

0.4

0.6

0.8

1

1.2

CW-01 CW-02 CW-03 CW-08 CW-11 CW-04 CW-05 CW-06 CW-07 CW-09 CW-10 CW-12

Me

an A

CQ

Sco

res

Subject ID

Males Females

13 ppb,86.14%

7 ppb,99.7%

7 ppb,63%

46 ppb,77%

8 ppb,106.9%

30 ppb,69%

20 ppb,70.7%

37 ppb,96.4%

22 ppb,90.4%

43 ppb,100%

41 ppb,88.7%

5 ppb,103.9%

Data from School FB • 11 subjects in the study cohort

• 6 Females, 5 Males

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

FB-1 FB-3 FB-5 FB-8 FB-9 FB-10 FB-2 FB-4 FB-6 FB-7 FB-11

Mea

n A

CQ

Sco

res

Subject ID

Bliss Elementary School

7 ppb, 80.1%

78 ppb, 89.4%

33 ppb, 79.9%

7 ppb 45 ppb, 76.6%

64 ppb, 96.9% 13 ppb,

76.1%

25 ppb

7 ppb, 100.4%

75 ppb, 87.6%

30 ppb, 82.8%

Females

Males

Overall Associations between ACQ and (24-/48-/72-/96-hr) Pollutant Metrics

Linear mixed effect models (nested model) with school- and subject-specific random intercept and AR(1) correlation including covariates

Pollutant SamplingPeriod

Site IQR Change in ACQ/IQR

p value

PM2.5 96 hr CW 4.15 -0.11 0.0681

PM10 24 hr Overall 30.82 0.09 0.0576

PM10 24 hr FB 20.65 0.08 0.0401

PM10 96 hr CW 10.42 -0.09 0.0392

O3 48 hr Overall 8.06 -0.10 0.0552

O3 48 hr FB 6.56 -0.11 0.0647

AQR 96 hr CW 19.45 -0.12 0.0585

Overall and Subject-specific Associations between ACQ and 24hr Averaged PM2.5**Linear mixed effect models (nested model) with school- and subject-specific random intercept and AR(1) correlation. Including covariates

Pollutant (IQR) Subject-specific Factor

Chg in ACQ per IQR increase in pollutant 95%CI.lwr 95%CI.upr p.value

PM2.5.24hr (6.69) 0.044 -0.014 0.103 0.136

Gender Female 0.001 -0.083 0.084 0.990

Male 0.085 0.005 0.166 0.038Father with Asthma Yes -0.037 -0.154 0.080 0.533

No 0.071 0.005 0.138 0.037Father with Hay Fever Yes -0.002 -0.093 0.090 0.974

No 0.074 0.000 0.149 0.052Siblings with Hay Fever Yes -0.029 -0.112 0.053 0.484

No 0.116 0.036 0.196 0.005

Overall and Subject-specific Associations between ACQ and 24hr Averaged PM10**Linear mixed effect models (nested model) with school- and subject-specific random intercept and AR(1) correlation. Including covariates

Pollutant (IQR) Subject-specific Factor

Chg in ACQ per IQR increase in pollutant 95%CI.lwr 95%CI.upr p.value

PM10.24hr (30.82) 0.091 -0.003 0.185 0.058

Gender Female 0.003 -0.127 0.133 0.960

Male 0.173 0.049 0.297 0.007Father with Asthma Yes -0.057 -0.233 0.120 0.530

No 0.141 0.035 0.247 0.009Father with Hay Fever Yes 0.015 -0.117 0.146 0.828

No 0.157 0.033 0.281 0.013Siblings with Hay Fever Yes -0.030 -0.153 0.093 0.633

No 0.230 0.100 0.359 0.001

Overall and Subject-specific Associations between ACQ and 24hr Averaged NO2**Linear mixed effect models (nested model) with school- and subject-specific random intercept and AR(1) correlation. Including covariates

Pollutant (IQR) Subject-specific Factor

Chg in ACQ per IQR increase in pollutant 95%CI.lwr 95%CI.upr p.value

NO2.24hr (8.14) 0.033 -0.058 0.125 0.476

Gender Female -0.043 -0.173 0.086 0.512

Male 0.103 -0.018 0.223 0.098Father with Asthma Yes 0.060 -0.112 0.232 0.495

No 0.024 -0.080 0.128 0.650Father with Hay Fever Yes 0.074 -0.045 0.193 0.224

No -0.020 -0.151 0.110 0.760Siblings with Hay Fever Yes 0.027 -0.090 0.143 0.653

No 0.044 -0.093 0.181 0.529

Overall and Subject-specific Associations between ACQ and 24hr Averaged O3*

Pollutant (IQR) Subject-specific Factor

Chg in ACQ per IQR increase in pollutant 95%CI.lwr 95%CI.upr p.value

O3.24hr (13.46) -0.076 -0.209 0.057 0.263

Gender Female -0.073 -0.241 0.094 0.392

Male -0.078 -0.238 0.082 0.337Father with Asthma Yes -0.127 -0.334 0.080 0.231

No -0.057 -0.201 0.087 0.439Father with Hay Fever Yes -0.090 -0.249 0.068 0.266

No -0.058 -0.227 0.112 0.504Siblings with Hay Fever Yes -0.122 -0.276 0.032 0.123

No -0.008 -0.183 0.167 0.927

Overall and Subject-specific Associations between ACQ and 24hr Averaged AQG**Linear mixed effect models (nested model) with school- and subject-specific random intercept and AR(1) correlation. Including covariates

Pollutant (IQR) Subject-specific Factor

Chg in ACQ per IQR increase in pollutant 95%CI.lwr 95%CI.upr p.value

AQG.24hr (28.36) 0.037 -0.038 0.111 0.333

Gender Female -0.004 -0.108 0.100 0.939

Male 0.075 -0.026 0.177 0.147Father with Asthma Yes -0.073 -0.214 0.067 0.308

No 0.076 -0.009 0.161 0.082Father with Hay Fever Yes -0.027 -0.141 0.086 0.636

No 0.081 -0.014 0.176 0.097Siblings with Hay Fever Yes -0.077 -0.179 0.024 0.136

No 0.151 0.050 0.252 0.004

Conclusions

• Air pollution panel studies mirror a brief snapshot in space and time of a potential exposure response relationship.

• 24 hr exposure levels more robust to elicit a statistically detectable response in ACQ.

• ACQ scores are also dependent on the person answering the questions in terms of their understanding of the questions and personal perception of asthma symptom severity.

• Our current findings strongly warrant additional studies with larger sample sizes that might be able to detect significant changes in ACQ scores based on the various pollutants and their levels.

Thank You