FeNO, Several Exacerbations Linked to Loss of Asthma Control

Bo Chawes, MD, PhD

Utilizing Global Initiative for Asthma (GINA) guidelines, a retrospective follow-up study from Denmark investigated the myriad of risk factors for loss of asthma control and found that female sex, higher baseline to GINA treatment, and higher fractional exhaled nitric oxide (FeNO) levels increased the risk of loss of disease control.

Previous studies had focused primarily on short-term loss of control and readmission rates among children with more severe disease and a history of exacerbations, though most only investigated 1 or few risk factors.

Additionally, metanalysis of studies including 5 -15-year-old patients who were predominantly recruited from an emergency department (ED) or as inpatients showed that female sex, younger age, and lower socio-economic status increased the risk of short-term ED reattendance and hospital readmission within 6 months.

In the current study, Bo Chawes, MD, PhD, DMSc, Department of Pediatric and Adolescent Medicine, Herlev and Gentofte Hospital, University of Copenhagen, and fellow investigators investigated a multitude of potential risk factors for loss of asthma control over a 5-year follow-up period among well-controlled children with mild to moderate asthma followed in a pediatric asthma outpatient clinic in Denmark.

They would define loss of control by hospital admissions, pediatric ED, and outpatient management of exacerbations, among other factors.

The Methods

The loss of asthma control was evaluated in 146 school-aged children with well-controlled mild-to-moderate asthma followed at the pediatric asthma clinic at Herlev-Gentofte Hospital, all of whom attended an exercise challenge test during 2015.

Inclusion criteria were asthma diagnosed by a pediatrician at the outpatient clinic according to the GINA guidelines at least 1 follow-up visit to the outpatient clinic during a 5-year period.

Investigators also considered several risk factors such as sex, ethnicity, age, body mass index, allergic sensitization, physical activity, adherence to treatment, and more.

Loss of asthma control end-points were hospital admission, treatment in the pediatric ED, short-term increase in short-acting beta-2-agonist (SABA) prescribed by the outpatient clinic, prescription of OCS, and GINA step-up of regular asthma treatment.

A combined variable of any hospital admission, ED visits, and outpatient management of exacerbations was considered “acute asthma”.

The Findings

Investigators reported that 13 (9%) of children were treated in pediatric ED during the 5-year study period, and 23 (16%) were managed in the outpatient clinician for exacerbations. A total of A total of 27 children (18%) experienced an acute asthma event with a total of 56 events.

Additionally, OCS was prescribed to 10 (7%) and GINA treatment step was increased at least once in 59 (41%) and at least twice in 17 (12%).

Chawes and colleagues also noted a strong association between female sex and loss of asthma control. Other factors such as age, ethnicity, BMI, atopic comorbidities and predispositions, lung function, exercise test results, or treatment adherence showed little or no association with loss of asthma control.

The investigative team considered the long-term design of their study to be a significant strength, though they believed their retrospective study could have benefitted from having a larger population.

“These findings are important for primary care physicians and clinicians in asthma outpatient clinics to identify seemingly well-controlled children with mild to moderate asthma, who are at risk to plan more frequent follow-ups and home asthma management plans to improve their health and quality of life,” the team wrote.

The study, “Long-term predictors of loss of asthma control in school-aged well-controlled children with mild to moderate asthma: A 5-year follow-up,” was published online in Pediatric Pulmonology.