INTRODUCTION
Asthma is one of the most common chronic diseases in childhood with an
increasing prevalence worldwide1. It is a
heterogeneous inflammatory disease of the airways which is characterized
by recurrent wheezing episodes, cough, dyspnea and chest tightness
during daily activity and sleep.1 Childhood asthma has
a wide variation in age of onset, type and frequency of respiratory
symptoms, exacerbations, triggers, lung functions, comorbidities and
underlying inflammatory patterns. Therefore, an individualized approach
may be needed to improve asthma outcome and reduce future risks as
exacerbations and decline in lung function and side effects of
therapy.2
Since 2000s, international asthma guidelines, such as the Global
Initiative for Asthma(GINA)1 and the National Asthma
Education and Prevention Program(NAEPP)3, recommend to
achieve “control” in asthma which means efective management of the
clinical characteristics of the disease. These are symptoms, nocturnal
awakening, reliever use, activity limitation and lung function. The
level of asthma control is the extent to which the manifestations of
asthma can be observed in the patient, or have been reduced or removed
by treatment.1 Although they are on controller
therapy, a considerable proportion of children have suboptimal asthma
control.4 This means despite regular treatment
guidelines, numerous children suffer from sleep disturbances, exercise
intolerance and need unscheduled health care visits and even
hospitalization that results in school absenteeism.5Hence, there is a need for validated and noninvasive instruments to
assess asthma control in children providing compatible results with the
gold standard guidelines.
There are several validated tools developed to guide asthma specialists
to determine asthma control and modify therapy. Asthma Control Test(ACT)
and Pediatric Asthma Control Test(PACT) are the numeric tools for
assessing symptom control recommended by GINA.1 Both
are validated and reliable tests used worlwide. Neverthless, the
compatibility and cut-off values of ACT/PACT which reflect the patients’
and/or caregivers’ perception of asthma symptoms according to GINA based
control measurement for children are challenging.6-10
Although lung function does not correlate strongly with asthma symptoms
in children, forced expiratory volume in 1 second(FEV1)
is requested to be used by GINA, because of the relation with asthma
control and future exacerbations.1 So, it should be
used while regular asthma follow-up as a component of evaluation of
asthma control based on GINA criteria.1
Fractional exhaled nitric oxide(FeNO) is an inflammatory marker of
airways which is noninvasive, reproducible and relatively easy to use in
patients.11 High FeNO at the time of loss of asthma
control and decrease of FeNO after treatment with corticosteroids imply
that FeNO may be useful not only to predict asthma excerbations, but
also be helpful in monitoring the response to
treatment.12 This inspired many researchers that FeNO
could be utilized as a tool for assessment of asthma control, but its
use for this purpose needs to be further clarified particularly in
children.11
Pediatric Asthma Quality of Life Questionnaire(PAQLQ) was developed as a
self-administered test by Juniper et al in 1996.13 It
comprises of 3 domains as symptoms, emotional functions and activity
limitation. Children and adolescents with poor asthma control will have
more frequent symptoms, medication use and activity limitation which
means impairement of health related quality of life.14,
15 And, this can be detected by PAQLQ which is invented for asthmatic
children specifically.
Therefore, assessing asthma control in childhood is a crucial step in
asthma management as in adults. The relationship of different tools with
GINA criteria in assessing asthma control was investigated in the
literature. Most studies manifested different results, beacuse they were
performed in different countries and care settings, with different study
plans and methods. Neverthless, clinicans working with children need to
know which tool can be confidentially used to assess asthma control
properly in real-world settings. Based on this need, we planned this
study to evaluate the compatibility of the common used tools for
assessing asthma control(ACT, PACT, PAQLQ, FeNO, lung function) with
GINA criteria in daily clinical practice.