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Keywords:

  • Asia;
  • asthma;
  • asthma control;
  • health survey;
  • pediatrics

Abstract

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information

Background

We conducted Phase 2 of the Asthma Insights and Reality in the Asia-Pacific (AIRIAP 2) survey in 2006 to determine the level of asthma control in this region and the validity of the Asthma Control Test™ (ACT) and childhood ACT (C-ACT) in relation to asthma control.

Methods

Pediatric participants (0 to <16 years; N = 988) with diagnosed asthma and current asthma symptoms or taking anti-asthma medications were recruited from 12 geographic areas in Asia. The survey consisted of the AIRIAP 2 questionnaire (asthma symptoms, use of urgent healthcare services and anti-asthma medication) and the ACT or C-ACT (English or Chinese translations only), both administered in the participant's preferred language. A symptom control index based on the Global Initiative for Asthma criteria (except lung function) was used to classify asthma control status.

Results

Most participants had inadequately controlled asthma (‘uncontrolled’ = 53.4%, 528/988; ‘partly controlled’ = 44.0%, 435/988). Only 2.5% (25/988) had ‘controlled’ asthma. Demand for urgent healthcare services (51.7%, 511/988) and use of short-acting beta-agonists (55.2%, 545/988) was high. The optimal ACT and C-ACT cutoff score for detecting uncontrolled asthma (compared with controlled or partly controlled asthma) was determined to be ≤19 (receiver operating characteristic analysis) with good agreement between the ACT and C-ACT and the symptom control index.

Conclusions

Findings from this survey show that asthma control is suboptimal in many children in the Asia-Pacific region. Practical tools, such as the ACT or C-ACT, may help clinicians assess asthma control and facilitate adjustment of asthma medication.

Asthma is a common chronic disease of childhood. However, asthma is poorly controlled in most pediatric patients worldwide [1], despite clinical guidelines, such as the Global Initiative for Asthma (GINA) [2], advocating asthma control as the primary goal of asthma management. Poor asthma control causes frequent asthma symptoms, disrupted sleep, and high rates of unscheduled emergency room visits and hospitalization [1], limiting a child's capacity to engage and participate in daily life [3, 4]. The overestimation of asthma control and the underestimation of asthma severity by healthcare professionals [5] and parents and caregivers [6, 7] are common barriers to achieving adequate asthma control.

In Asia, achieving adequate asthma control in pediatric patients has become a key healthcare priority because the prevalence of asthma is increasing [8, 9]. Findings from Phase 1 of the Asthma Insights and Reality in Asia-Pacific (AIRIAP 1) survey, conducted in 2000, suggested that there were unmet needs concerning asthma control in this region, particularly among pediatric participants [10]. To address these unmet needs, the use of practical tools that assess the GINA criteria for asthma control, such as the Asthma Control Test™ (ACT) [11] and childhood ACT (C-ACT) [12], may assist with identifying pediatric patients with suboptimal asthma control.

In 2006, we conducted Phase 2 of the AIRIAP (AIRIAP 2) survey, which indicated that poor asthma control was still prevalent within the Asia-Pacific region [13]. Herein, we report the AIRIAP 2 findings for pediatric participants (aged 0 to <16 years), including their level of asthma control and the validity of the ACT and C-ACT in relation to asthma control.

Materials and methods

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information

Study design

This was a cross-sectional, community-based survey conducted from September 2006 to December 2006. The study methodology has been reported [13] and is described briefly here. The 12 geographic areas selected and surveyed for AIRIAP 2 were major urban areas in mainland China, Hong Kong, India, Indonesia, Malaysia, the Philippines, Singapore, South Korea, Sri Lanka, Taiwan, Thailand, and Vietnam. The survey was approved by the ethics committee of the Chinese University of Hong Kong. Verbal consent was provided by the parent or legal guardian of participants.

Participant recruitment

Pediatric participants (0 to <16 years) were recruited by random door-to-door visits, random street interception, or peer referral [13]. The sampling population was considered to be all persons located in the geographic areas surveyed who were approached by an AIRIAP 2 survey recruiter. The planned sample size for each geographic area was 400; no financial incentives were offered for survey participation. Recruiters asked each person to identify household members with asthma, defined as asthma diagnosed by a physician and either the current use of asthma medication or asthma attacks or symptoms during the past 12 months. Households with at least one member with asthma qualified; however, only one member per household, selected at random using standard Kish selection grid methodology [14], could participate in the survey.

Survey

The duration of the survey was 30–45 min. Subjects were interviewed with the parent or caregiver most familiar with their asthma and treatment. The survey consisted of two parts. First, all participants were administered the AIRIAP 2 questionnaire [13] (see Supporting Information) face-to-face by a trained interviewer in the participant's preferred language. Second, participants aged 12–15 years self-completed the ACT, and participants aged 4–11 years, with their parent or caregiver, completed the C-ACT (available at www.asthmacontroltest.com). The ACT was administered in the participant's preferred language and consists of five questions [11], with minimum and maximum overall scores of 5 (totally uncontrolled) and 25 (well controlled), respectively. The C-ACT was administered in English or Chinese translations only and consists of seven questions [12], with minimum and maximum overall scores of 0 (totally uncontrolled) and 27 (well controlled), respectively. Participants aged <4 years and participants aged 4–11 years (and their parents or caregivers) who did not read English or Chinese did not complete the second part of the survey.

Outcome measures

The primary outcome measure was asthma control as measured by the symptom control index (SCI; Table 1). The SCI was developed by matching specific AIRIAP 2 questions to the GINA criteria for asthma control [2] (except lung function). These questions were about daytime and nocturnal symptoms, reliever or rescue medication use, symptom effect on daily life, and exacerbations (defined as hospitalization, emergency visits, or other unscheduled urgent healthcare visits). Based on their responses to these questions, participants' asthma was classified as ‘controlled’ (did not meet any GINA criteria), ‘partly controlled’ (met 1–2 GINA criteria), or ‘uncontrolled’ (met ≥3 GINA criteria).

Table 1. Symptom control index (SCI) classification based on the 2006 Global Initiative for Asthma (GINA) criteria for asthma control
GINA criteriaMatched AIRIAP 2 QuestionsAIRIAP 2 Question Response that Fulfills GINA Criteria
  1. a

    Limitation of activities = limited participation in sports and recreation, normal physical exertion, social activities or playing, sleeping, lifestyle, or housekeeping chores.

  2. AIRIAP, Asthma Insights and Reality in Asia-Pacific.

1. Daytime symptoms (previous 4 weeks)a. Daytime symptomsYes AND
b. Frequency>2/week
2. Nocturnal symptoms and awakenings (previous 4 weeks)a. Nocturnal symptoms and awakeningsYes
3. Need for reliever/rescue treatmenta. Need for reliever/rescue treatmentYes AND
b. Frequency>3/week
4. Limitation of activitiesa. Missed school or workYes OR
b. Limitation of activitiesa‘Only a little’, ‘Some’, or ‘A lot’ for any activity
5. Exacerbations (previous 12 months)a. HospitalizationYes to any exacerbation type
b. Emergency room visit
c. Other unscheduled visit
Number of AIRIAP 2 Question Responses that Fulfill GINA Criteria (out of 5) and SCI Classification:0, controlled
1 to 2, partly controlled
≥3, uncontrolled

Secondary outcome measures were i) asthma control as measured by the ACT or C-ACT, ii) asthma severity as measured by the symptom severity index (SSI), iii) use of urgent healthcare services and anti-asthma medication, and iv) asthma symptoms and restrictions. The SSI (Table 2) was developed by classifying participants' responses to specific AIRIAP 2 questions. These questions were about the frequency of asthma symptoms, including daytime and nocturnal symptoms, severe symptoms (e.g., wheezing, chest tightness), and exercise-induced symptoms. Based on their responses to these questions, participants' asthma severity was classified as ‘severe persistent’, ‘moderate persistent’, ‘mild persistent’, or ‘mild intermittent’.

Table 2. Symptom severity index classification
 Symptom Severity Index Classification
AIRIAP 2 QuestionMild IntermittentMild PersistentModerate PersistentSevere Persistent
  1. AIRIAP, Asthma Insights and Reality in Asia-Pacific.

Frequency of:
Daytime symptoms (previous 4 weeks)≤1/week≥2/weekEvery day (≤2/day)≥3/day
Nocturnal symptom awakenings (previous 4 weeks)≤1/month≥2/month≥2/weekEvery day or most days
Sudden severe coughing, wheezing, chest tightness, or shortness of breath (previous 12 months)≤1/week≥2/weekEvery dayEvery day
Symptoms bought on by exercise or exertion (previous 12 months)≤1/week≥2/weekEvery dayEvery day
Symptoms during a typical week≤2/week3 to 6/week7 to 20/week≥21/week

Statistical analysis

Categorical variables are reported as counts and percentages and continuous variables as means and standard deviations (SD). The optimal ACT and C-ACT cutoff score for detecting uncontrolled asthma was determined by receiver operating characteristic (ROC) analysis, and sensitivity and specificity statistics, and positive and negative predictive values were calculated. The ACT and C-ACT score with the highest sum of sensitivity and specificity for classifying patients as uncontrolled (compared with controlled or partly controlled) as per the GINA-derived SCI was selected as the optimal cutoff score. Urgent healthcare service use (hospitalization and emergency room visits) within the SCI categories (uncontrolled versus controlled and partly controlled) was assessed using the chi-square test with results presented as odds ratios (ORs) and 95% confidence intervals (95% CI). < 0.05 was considered to be significant. Statistical analysis was performed using spss, version 16 (SPSS Inc., Chicago, IL, USA).

Results

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information

Demography and baseline clinical characteristics

The proportion of participants surveyed for AIRIAP 2 who were aged <16 years was 20.6% (988/4,805) overall and varied from 4.8% (19/397, Hong Kong) to 51.0% (204/400, Philippines; Table 3). The mean (±SD) age of pediatric participants was 7.7 (±4.0) years; 17.2% (170/988) were <4 years. More than half of the participants were male. Overall, 51.4% (508/988) of pediatric participants lived in households where someone smoked; however, this proportion differed among the geographic areas surveyed.

Table 3. Participant demographics and characteristics
VariableOverallHong KongIndiaIndonesiaMainland ChinaMalaysiaPhilippinesSingaporeSouth KoreaSri LankaTaiwanThailandVietnam
  1. SD, standard deviation.

Total surveyed, N4 805397407400402404400399400401400395400
Participants <16 years, n (%)988 (20.6)19 (4.8)54 (13.3)61 (15.3)36 (9.0)127 (31.4)204 (51.0)89 (22.3)94 (23.5)73 (18.2)65 (16.3)53 (13.4)113 (28.3)
Recruitment method, n (%)
Door-to-door641 (64.9)0 (0)54 (100)61 (100)7 (19.4)58 (45.7)204 (100)71 (79.8)0 (0)73 (100)0 (0)0 (0)113 (100)
Street intercept226 (22.9)19 (100)0 (0)0 (0)29 (80.6)0 (0)0 (0)18 (20.2)42 (44.7)0 (0)65 (100)53 (100)0 (0)
Peer referral121 (12.2)0 (0)0 (0)0 (0)0 (0)69 (54.3)0 (0)0 (0)52 (55.3)0 (0)0 (0)0 (0)0 (0)
Age (years), mean ± SD7.7 ± 4.08.0 ± 3.78.1 ± 3.97.4 ± 4.37.6 ± 4.09.0 ± 3.85.6 ± 3.89.6 ± 3.87.8 ± 3.68.3 ± 4.08.6 ± 3.27.1 ± 4.27.5 ± 4.1
Age (years) at diagnosis, mean ± SD3.4 ± 3.03.2 ± 2.64.3 ± 3.62.9 ± 3.14.3 ± 2.83.6 ± 3.01.9 ± 2.24.2 ± 2.84.6 ± 3.33.4 ± 3.33.6 ± 2.13.6 ± 3.73.6 ± 3.1
Male, n (%)566 (57.3)10 (52.6)39 (72.2)30 (49.2)21 (58.3)70 (55.1)105 (51.5)55 (61.8)52 (55.3)43 (58.9)45 (69.2)29 (54.7)67 (59.3)
Smoker in household, n (%)508 (51.4)5 (26.3)12 (22.2)42 (68.9)16 (44.4)54 (42.5)137 (67.2)39 (43.8)35 (37.2)39 (53.4)32 (49.2)26 (49.1)71 (62.8)

Asthma control, severity, and symptoms

More than half (53.4%, 528/988) of the pediatric participants had uncontrolled asthma, as per the GINA-derived SCI, whereas only 2.5% (25/988) had controlled asthma (Fig. 1A). This finding was somewhat consistent across the geographic areas surveyed. A quarter (25.4%, 251/988) of the participants had moderate to severe persistent asthma symptoms, as per the SSI (Fig. 1B).

image

Figure 1. (A) Asthma control as per the Global Initiative for Asthma (GINA)-derived symptom control index (SCI) and (B) asthma severity as per the symptom severity index (SSI). Participants' asthma was classified as uncontrolled, partly controlled, or controlled as per the GINA-derived SCI. Participants' symptom severity was classified as mild intermittent, mild persistent, moderate persistent, or severe persistent as per the SSI. Data are presented for the overall pediatric survey population and for each of the study geographic areas.

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The effect of asthma on daily life and functioning was evident. More than half (54.9%, 542/988) of the participants had daytime asthma symptoms during the previous 4 weeks, 40.0% (395/988) had experienced restrictions to their normal physical activity, 29.1% (288/988) had disrupted sleep at least once every week, and 44.0% (435/988) missed school or work in the previous year because of asthma symptoms or exacerbations.

Use of urgent healthcare services and anti-asthma medication

Use of urgent healthcare services was high overall (51.7%, 511/988) and highest in participants with uncontrolled asthma (76.9%, 406/528; Fig. 2A). Participants with uncontrolled asthma had significantly higher odds of hospitalization (35.8% [189/528] vs 7.2% [33/460], OR [95% CI] = 7.2 [4.9–10.7], < 0.0001) and emergency room visits (42.6% [225/528] vs 9.6% [44/460], OR [95% CI] = 7.0 [4.9–10.0], < 0.0001) than participants with partly controlled and controlled asthma.

image

Figure 2. Use of (A) urgent healthcare services and (B) anti-asthma medication. Data are presented for the overall pediatric survey population and for the Global Initiative for Asthma (GINA)-derived symptom control index classifications: controlled, partly controlled, and uncontrolled. Abbreviations: ER, emergency room; Hosp., hospitalization; ICS, inhaled corticosteroids; SABA, short-acting beta-agonists.

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Anti-asthma medication use was also high overall (66.6%, 658/988) and highest in participants with uncontrolled asthma (73.3%, 387/528; Fig. 2B). Participants with uncontrolled asthma using anti-asthma medication favored short-acting beta-agonists (61.9%, 327/528) over inhaled corticosteroids (ICS; 18.8%, 99/528; Fig. 2B). The proportion of participants using ICS who had mild to severe persistent asthma symptoms (16.8%, 83/493) or mild intermittent asthma symptoms (20.0%, 99/495), as per the SSI, was similar.

ACT and C-ACT

The optimal ACT and C-ACT cutoff score for detecting uncontrolled asthma, compared with controlled or partly controlled asthma, was determined to be ≤19. The cutoff score of ≤19 yielded a sensitivity and a specificity of 0.65 and 0.91, respectively, for the ACT (predictive values, positive = 0.87 and negative = 0.75) and 0.61 and 0.84, respectively, for the C-ACT (predictive values, positive = 0.86 and negative = 0.59).

Most participants (94.2%, 194/206) aged 12–15 years completed the ACT, whereas 26.5% (162/612) participants aged 4–11 years completed the C-ACT. Findings suggested agreement between the ACT and C-ACT scores and the GINA-derived SCI (Table 4). Most participants who scored ≤19 (the optimal ACT and C-ACT cutoff score for detecting uncontrolled asthma) had uncontrolled asthma as per the GINA-derived SCI. However, some participants who scored >19 (controlled or partly controlled asthma) had uncontrolled asthma as per the GINA-derived SCI.

Table 4. Agreement between the Asthma Control Test (ACT) and childhood ACT (C-ACT) scores and the Global Initiative for Asthma (GINA)-derived symptom control index (SCI) classification for pediatric participants
   GINA-derived SCI, n (%)
  Overall, n (%)Controlled/Partly ControlledUncontrolled
  1. a

    ≤19 = optimal ACT and C-ACT cutoff score for detecting uncontrolled asthma.

  2. b

     >19 = optimal ACT and C-ACT cutoff score for detecting controlled or partly controlled asthma.

ACT score (n = 194)≤19a68 (35.1)9/68 (13.2)59/68 (86.8)
>19a126 (64.9)94/126 (74.6)32/126 (25.4)
C-ACT score (n = 162)≤19b70 (43.2)10/70 (14.3)60/70 (85.7)
>19b92 (56.8)54/92 (58.7)38/92 (41.3)

Discussion

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information

Asthma, a common chronic disease of childhood, has a significant economic burden within the Asia-Pacific region [15]. In conducting Phase 2 of the AIRIAP survey, we established the largest dataset available of asthma control in pediatric participants from 12 geographic areas in this region. We found that most pediatric participants had poor asthma control, similar to findings from other studies that assessed asthma control in children and adolescents using the GINA criteria [6, 16-18]. Given that poor asthma control is a risk factor for future asthma exacerbations and hospitalizations [19], it is not surprising that we found the use of urgent healthcare services and short-acting beta-agonists by pediatric participants to be high. These findings indicate that there are still unmet needs concerning asthma control in this region, and the use of practical tools, such as the ACT and C-ACT, may aid the assessment and management of asthma control.

The findings from AIRIAP 2, compared with those from AIRIAP 1, suggest little improvement in asthma outcomes for pediatric patients in the Asia-Pacific region. For example, 44% of pediatric participants in AIRIAP 2 compared with 37% in AIRIAP 1 [10] missed school or work in the previous year because of asthma symptoms or exacerbations. The low use of ICS (18.4%) may have been a contributing factor for this lack of improvement [20]. The use of ICS may be low because patients are not being treated according to regional and global treatment guidelines. Despite the number and availability of these guidelines, their dissemination and implementation are key challenges [21]. Alternatively, patients may be reluctant to use ICS even if prescribed by their treating physician. To counter patient reluctance, nurses who support prescribing physicians by educating patients about ICS and correct inhaler use may help increase patient acceptance of ICS and consequently improve asthma control [22]. Other reasons for the lack of improvement in asthma outcomes include infrequent asthma monitoring, a parent's or caregiver's lack of sufficient knowledge about their child's asthma, comorbidities that may make asthma worse (e.g., allergic rhinitis, gastro-esophageal reflux), or frequent exposure to asthma triggers such as environmental tobacco smoke, which was experienced by approximately 50% of pediatric participants in our survey. Reducing children's exposure to environmental tobacco smoke may improve asthma control and reduce asthma morbidity [23, 24]. Thus, advocating smoking cessation in households with children with asthma should be a priority in many Asian countries where the rate of smoking is high [25, 26]. Furthermore, poor control of concomitant allergic rhinitis may have also contributed to poor control of asthma; this relationship has been well documented in the literature [2, 27].

We found that the ACT and C-ACT were useful tools for detecting uncontrolled asthma as per the GINA-derived SCI; acceptable agreement between these tools and the GINA criteria has been reported elsewhere [16-18, 28]. The cutoff score of ≤19 to detect uncontrolled asthma has been validated by an asthma specialist [11, 12, 29] and by ROC analyses in another study [18]. However, a cutoff score of ≤19 may underestimate the proportion of those with uncontrolled asthma as classified by the GINA criteria [6, 16-18]. A reason for this discrepancy may be that the GINA criteria are more stringent than the C-ACT criteria [6]. Also, the parent's, caregiver's, and child's awareness of and ability to recall asthma symptoms and events may be limited, and poor symptom perception may result in high ACT or C-ACT scores [18]. Many parents and caregivers in our study believed their child's asthma to be well controlled despite moderate or severe persistent asthma symptoms (data not shown). Despite these limitations, however, the ACT and C-ACT can enable clinicians to apply the GINA criteria and monitor asthma control [11, 12].

We acknowledge that there are other limitations with our study. First, we did not include lung function tests in our survey even though they are an objective measure and a GINA criterion for asthma control. Lung function tests are not routinely done in Asia and many Western countries, especially in the primary care setting; up to two-thirds of pediatric participants in our survey had never had a lung function test. Second, our findings may not precisely represent the level of asthma control in the Asia-Pacific region because not all countries in the region were surveyed, the proportion of pediatric participants surveyed varied markedly among the geographic areas, and children from rural areas were not surveyed. Although the prevalence of asthma tends to be higher in urbanized areas of Asia [30], poor asthma control may be a particular problem in rural areas because of fewer healthcare resources. Finally, recruiting only those participants who had been diagnosed with asthma by a physician may have led to selection bias by favoring the recruitment of participants with more severe asthma. However, by excluding children with asthma but without a physician diagnosis of asthma, we may have underestimated poor asthma control because these children are less likely to be receiving appropriate asthma treatment.

Our finding that most children and adolescents in the Asia-Pacific region have poor asthma control indicates that there are still unmet needs concerning asthma control in this region. As the prevalence of asthma continues to rise in many areas of Asia [31], improving asthma control will help minimize the burden of asthma on healthcare budgets throughout Asia. Given the complexities and differences in healthcare systems among the various countries in this region, identifying patients with uncontrolled asthma with easy-to-use tools, such as the ACT or C-ACT, may be the first step for improving the level of asthma control in pediatric patients throughout the Asia-Pacific region.

Acknowledgments

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information

Funding Support

This study was sponsored by GlaxoSmithKline (GSK). In compliance with the Uniform Requirements for Manuscripts, established by the International Committee of Medical Journal Editors, the sponsor of this study did not impose any impediment, directly or indirectly, on the publication of the study's results. The authors acknowledge the independent medical writing assistance provided by Julie Monk, PhD, and Rebecca Lew, PhD, of ProScribe Medical Communications (www.proscribe.com.au), funded from an unrestricted financial grant from GSK. ProScribe's services complied with international guidelines for Good Publication Practice (GPP2).

Role of the sponsor

GlaxoSmithKline was involved in the study design, data collection, data analysis, and preparation of the manuscript.

Role of contributors

All authors participated in the interpretation of study results, and in the drafting, critical revision and approval of the final version of the manuscript. GW, J-YH, and KG were study investigators. GW and J-YH were involved in the study design. J-YH was involved in data collection. GW was involved in statistical analysis. GW, JH, J-YH, KG, and NK were involved in the interpretation of the study data.

Conflict of interest

All authors, except NK, received travel grants from GlaxoSmithKline (GSK) to attend AIRIAP 2 Steering Committee meetings. GW has received lecture fees and travel grants from Astra-Zeneca, GSK, and Merck Sharp & Dohme. J-YH has received study support and speakers' bureau fees from Astra-Zeneca, GSK, and Boehringer Ingelheim. NK is an employee of, and owns shares in, GSK. KG and JH have no conflicts of interest to declare.

References

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information

Supporting Information

  1. Top of page
  2. Abstract
  3. Materials and methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. References
  8. Supporting Information
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