Study highlights lack of gold standard for measuring asthma control in pediatric patients

In a recent article published in the npj Primary Care Respiratory Medicine Journal, researchers systematically reviewed studies comparing questionnaires assessing asthma control measures in children in primary care.

Notably, asthma measure control has two main domains: managing symptoms and predicting the risk of adverse outcomes in the future.

Study: A systematic review of questionnaires measuring asthma control in children in a primary care population. Image Credit: DraganaGordic/Shutterstock.com

Background

In children, asthma, a chronic pulmonary disease characterized by wheezing, coughing, dyspnea, and airway inflammation, is prevalent, especially among primary care patients. 

Even suboptimal or uncontrolled asthma in children could hamper health-related quality of life (HRQL). Thus, it is crucial to assess asthma control measures for insights into disease burden so that clinicians devise the best treatment strategy for pediatric asthma patients.

Besides clinical tests, e.g., spirometry, several questionnaires have helped measure asthma control in children. Examples include the Childhood Asthma Control Test (C-ACT) and the Asthma Control Questionnaire (ACQ). However, studies have evaluated, validated, and compared these in secondary and tertiary care settings but only among adults in primary care settings.

Given General Practitioners (GPs) have limited time available for pediatric consultations, there is an urgent need to identify the most appropriate tool for use in primary care that takes the least time to administer. 

Global Strategy for Asthma Management and Prevention (GINA) guidelines are used in primary care to determine pediatric asthma control. However, there remains an unmet need for a ‘gold standard’ of reference when determining asthma control in pediatric populations. 

About the study

In the present study, researchers measured and compared the psychometric features of various asthma control questionnaires used in primary care based on six prespecified criteria, as follows:

i) questionnaire characteristics;

ii) questionnaire quality;

iii) asthma symptoms evaluated by these questionnaires

iv) association or some level of agreement in their determination of asthma measure control

v) whether or not these questionnaires detected uncontrolled asthma

vi) ability of questionnaires to predict future events

Three reviewers independently screened Google Scholar, Embase, MEDLINE, Web of Science, and Cochrane databases up to 24 June 2022 to identify relevant English, Dutch, or Spanish studies and extract data.

They analyzed full-text of studies only if they met the inclusion criteria of evaluating children with asthma aged five to 18 years and living in primary care. For select screened publications, they also screened references to identify additional relevant research papers.

Two independent reviewers used the COSMIN quality criteria to assess the methodological quality of health status questionnaires. Subsequently, they scored the questionnaires on several parameters, e.g., content validity, consistency, interpretability, and reproducibility, to name a few.

Based on the study design, the following studies met the inclusion criteria, randomized controlled trials (RCTs), cross-sectional and prospective cohort studies administering case-control questionnaires.

The team considered asthma diagnosis in children based on the following criteria:

i) A doctor diagnosed asthma;

ii) A doctor coded the diagnosis as asthma;

iii) Children had symptoms like breathlessness, chest tightness, cough, or wheezing, and in spirometry test, they had reversibility of FEV1 > 12%;

iv) Children used inhaled corticosteroids (ICS) to manage symptoms

Results

After removing the duplicates, the authors retrieved 7,536 articles, of which only 75 met the full-text screening criteria. However, the authors included only five studies in the trial’s qualitative synthesis.

These studies had 1,085 participants aged five to 71 years and only 806 children. While four of these five studies had an observational design, one was a substudy of an RCT. Intriguingly, these studies were too heterogeneous to pool data.

These studies compared seven structured and unstructured questionnaires, Asthma Control Questionnaire (ACQ), Asthma Control Test, C-ACT, Asthma Activities, Persistent, triGGers, Asthma medications, and Response to therapy (APGAR) system, National Asthma Education and Prevention Program (NAEPP), Royal College of Physicians three questions’ (RCP3Q), and Visual Analog Scale or VAS.

Based on this trial’s evaluation criteria, the asthma APGAR system emerged as a promising tool to determine asthma control in children in primary care as it showed good agreement with C-ACT but did not depend on spirometry results for completion.

However, as this system is a recently developed one, it requires further testing before use in real-world primary care settings.

Three articles described measurement characteristics of the RCP3Q questionnaire, with correlation varying from fair to good. The RCP3Q emerged as an effective tool for assessing asthma control in routine review consultations, but results were applicable for adults and children, not just children.

Further, the authors concluded that the VAS score predicted the results of symptom diary data. They also concluded that the Childhood Asthma Questionnaire (CAQ) is poorly validated, and the C-ACT requires further validation to prove it fetches asthma control accurately. 

Conclusions

The trial could not identify a gold (or reference) standard to measure asthma control in children for use in clinical practice. 

However, it remarkably highlighted the need for devising more convenient asthma control questionnaires for children that are relatively quicker to administer and complete, identify patients with uncontrolled asthma, and predict future events so that pediatric patients benefit from a change in drug dosage or treatment strategy.

None of the questionnaires evaluated in this trial provided any information on the outcome: risk of adverse future events. Thus, more studies are warranted to develop a questionnaire that addresses this limitation.