Scientific Papers

Test for Respiratory and Asthma Control in Kids (TRACK): validation of the Portuguese version | World Allergy Organization Journal

The translation of the TRACK questionnaire into Portuguese (Brazilian culture) was done by professional translators. After receiving the Portuguese version of the TRACK questionnaire, it was applied to parents of patients with asthma and/or respiratory symptoms to evaluate comprehension of the questionnaire. The cognitive testing was a cross-sectional, observational, qualitative evaluation with face-to-face interviews of a convenience sample of 10 children and their parents/caregivers. The authors considered that the comprehension of the questionnaire questions was satisfactory, and no changes in the questions would be necessary.

The validation of the Portuguese version of the TRACK questionnaire was done in an observational, prospective, longitudinal and multicenter evaluation. Children with recurrent respiratory symptoms attended at pediatric clinics were included in the study if they met the following inclusion criteria: age up to 5 years; medical diagnosis of asthma or history of at least 3 episodes of cough and/or wheeze and/or dyspnea (duration longer than 24 h) and treated with bronchodilators; native Portuguese speaking families. Exclusion criteria were: other relevant pulmonary diseases (i.e., cystic fibrosis, bronchopulmonary dysplasia); systemic diseases (i.e., heart diseases, neurologic disorders); congenital malformations; illiteracy and/or inability of parents to understand the questionnaire.

There was only 1 follow-up visit 4 weeks (3 to 5 weeks) after the inclusion in the study. Parents completed the TRACK questionnaire in both visits and answered additional questions about respiratory symptoms and use of medication. Children were classified as controlled, partly controlled and uncontrolled, according to Global Initiative for Asthma (GINA) [4] criteria. Medical evaluation was carried out by the attending allergy specialists, who were blinded to the questionnaires’ answers. Children’s symptom control was also classified in controlled, partly controlled and uncontrolled based on the clinical judgment of the physicians. Patients were further divided according to their symptoms, employing criteria used in the original validation of the TRACK questionnaire, in symptomatic (respiratory symptoms in the last 4 weeks), with recent symptoms (symptoms in the last year, but not in the last 4 weeks) and asymptomatic (without respiratory symptoms in the last year) [8]. Parents and doctors rated child respiratory symptom control in the last 4 weeks by means of 100 mm visual analog scale (VAS). Demographic and clinical data were obtained from medical records. Vital signs were checked in both visits. Weight (kg) and height (cm) were obtained only at first visit.

According to previous sample size calculation, at least 200 completed questionnaires at first assessment and 106 in longitudinal evaluation (53 of clinically stable group and 53 of unstable group) were necessary [10]. Thus, considering possible losses, we intended to include at least 220 children, with longitudinal evaluation in at least 140. Eligible children in each centre were screened for the study in sequential order until the estimated number of included children was completed.

The statistical analysis was carried out using SPSS 18.0 (SPSS Inc., Chicago, IL, USA). The level of significance was set at p < 0.05. The population characteristics were described using standard statistical techniques. Non parametric tests were used since data did not show normal distribution. The TRACK internal consistency was studied by the Cronbach’s α test. The TRACK criterion validation was performed by the comparison of the scores obtained from patients in the three levels of control, according to GINA criteria with Kruskal-Wallis one-way analysis of variance. Constructive validation was done by comparing the TRACK notes between patients discriminated according to their respiratory symptoms (symptomatic, recent symptoms, and asymptomatic) and to the medical opinion with Kruskal-Wallis one-way analysis of variance. Correlation between parent’s and medical VAS symptom control, and TRACK were calculated by Spearman’s coefficient test. Guyatt’s responsiveness index (GRI) was calculated by dividing the mean change of TRACK scores in the unstable group by the standard deviation (SD) of change in the stable group [13]. The test-retest reliability was assessed using intra-class correlation coefficient in clinically stable patients between visits.

Receiver operating characteristic (ROC) curves were constructed to establish TRACK cutoff score values, according to the GINA criteria of respiratory symptom control (controlled vs. partially controlled and uncontrolled symptoms). The minimal clinically important difference (MCID) for TRACK, which is the smallest difference that parents perceive as either beneficial or harmful, was established using anchor-based (GINA and medical classification of respiratory symptoms control, emergency visit due to wheezing in the last month) and distribution-based (0.5 SD and 1 standard error of the mean [SEM] at baseline and at follow-up) methods [9].

The study was initiated in each centre after approval by the local Institutional Review Board and after approval by the coordinating centre. Prior to participation in the study, written informed consent was obtained from parents.

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