Baseline characteristics, including demographic data, aeroallergen sensitization and patient medications were recorded for all patients. Children and parents completed the Childhood Asthma Control Test (C-ACT; official Turkish version [5]), Pediatric Asthma Quality of Life Questionnaire (PAQLQ), Pediatric Quality of Life Inventory (PedsQL), and also underwent spirometry.

An asthma specialist assessed the control status of each child according to GINA guidelines [4]. Patients were grouped as having well controlled, partly controlled, or uncontrolled asthma. Patients with partly controlled and uncontrolled asthma were further classified as having not controlled asthma.

All patients underwent a spirometry test using the ZAN100 spirometry system (nSpire Health, Longmont, Colorado, USA) to measure the prebronchodilator forced expiratory volume in 1 second (FEV1), the FEV1 to forced vital capacity (FVC) ratio, and the forced expiratory flow between 25% and 75% of vital capacity (FEF25%-75%).

The SPSS Statistics Version 21.0 (IBM, Chicago, IL, USA) was used for all calculations. Descriptive data for categorical and numerical variables were expressed as frequencies and medians with interquartile ranges. Group comparisons were established using Kruskal-Wallis tests or Mann-Whitney U-tests as appropriate, and the Chi-square test or Fisher test for categorical variables. Associations among the scores of C-ACT, PAQLQ and PedsQL, and asthma control status were evaluated using Spearman correlation coefficients. A P level <0.05 was considered significant.

Eighty-two children with a median (IQR) age of 10.1 (8.9-10.5) year were included in the study. Demographic characteristics are summarized in Table I. Asthma control status was ‘controlled’ in 52 (63.4%) children, ‘partly controlled’ in 17 (20.7%) children and ‘uncontrolled’ in 13 (15.9%) children. There were no statistically significant differences between children in terms of demographic data according to asthma control status.

TABLE I	Descriptive Characteristics of the Study Population (N=82)

C-ACT scores were significantly higher for patients with controlled asthma (25 vs. 20; P<0.001). PAQLQ scores, including symptoms (6.4 vs. 5.0; P<0.001), activity limitation (6.4 vs. 5.3; P<0.001), emotional function (6.8 vs. 5.4; P<0.001) and total scores (6.5 vs. 5.2; P<0.001), were significantly higher in children with controlled asthma. The PedsQL child scores, including physical health summary score (675 vs. 588; P=0.019), psychosocial health summary score (1300 vs. 1163; P=0.022) and total scale score (1962 vs. 1725; P=0.009), were significantly higher for children with controlled asthma.

The PedsQL parent physical health summary score (650 vs. 550; P=0.017) was significantly higher for parents of children with controlled asthma. The psychosocial health summary score (1150 vs. 1075; P=0.13), and total scale score (1788 vs. 1625; P=0.052) of parents of children with controlled asthma was not significantly different from those with children having partly controlled or uncontrolled asthma.

Significant direct correlations were found between the TSS and all subscale summary scores (TSS: r = 0.72, P<0.001; PsychoSS: r = 0.72, P<0.001; PSS: r = 0.63, P<0.001). When the correlation between parameters obtained from scales and asthma were analyzed, the most significant correlations were found between C-ACT and asthma control (r=0.572; P<0.001). There were also significant correlations between PAQLQ scores and asthma control.

In the present study, children with controlled asthma had significantly higher C-ACT, PAQLQ and PedsQL scores. C-ACT and PAQLQ have also emerged as better variables than PedsQL for identifying children with not-controlled asthma. Moreover, the performance of PedsQL-parent version in determining patients with uncontrolled asthma was poor in comparison. We observed that asthma control status of children directly affected both disease-specific and general quality of life scores.

Lower quality of life scores are usual in children with asthma in both general purpose and disease specific quality questionnaires. But in our study, when we examined the correlation of these two forms, there was a moderate statistically significant relation using PAQLQ but there was a poor relation using the PedsQL pediatric scale. The lower sensitivity of general life quality scales, longer completion time and their lower capacity to reflect minimal changes in children and adolescents may cause such results.

Assessing the quality of life in pediatric asthma patients helps the parents to better understand the disease and its treatment [10]. In a study that analyzed the concordance and consistency of child and parent scores in children’s quality of life questionnaires, there was a poor consistency between child and parent scores [11]. In our study, asthma control levels showed a decrease in the PedsQL physical health summary score but made no difference in the psychosocial health summary score. This result may be related to the parents giving more importance to their child’s physical wellness than their psychosocial condition.

The cross-sectional design of our study may be regarded as a limitation; longitudinal follow-up of the patients may inform us about the predictive performance of these tools for possible life quality changes and loss of asthma control.

We conclude that better asthma control leads to better quality of life for children with asthma. Asthma- specific quality of life scales correlate better with asthma control than general pediatric quality of life scales.

Contributors: STY:study concept, outcome assessment, and manuscript preparation; OS: data collection and manuscript writing; STY; UA, MG, YCD;data collection, data analysis and preparation of the manuscript.

Funding: None; Competing interest: None stated.