Clinical performance of spirometry and respiratory oscillometry for prediction of severe exacerbations in schoolchildren with asthma.

OBJECTIVE: To determine the performance of spirometry and respiratory oscillometry (RO) in the prediction of severe asthma exacerbations (SAEs) in children. METHODS: In a prospective study, 148 children (age 6-14 years) with asthma were assessed with RO, spirometry and a bronchodilator (BD) test. Based on the findings of spirometry and the BD test, they were classified into three phenotypes: air trapping (AT), airflow limitation (AFL) and normal. Twelve weeks later, they were re-evaluated in relation to the occurrence of SAEs. We analysed the performance of RO, spirometry and AT/AFL phenotypes for prediction of SAEs by means of positive and negative likelihood ratios, ROC curves with the corresponding areas under the curve (AUCs) and a multivariate analysis adjusted for potential confounders. RESULTS: During the follow-up, 7.4% of patients had SAEs, and there were differences between phenotypes (normal, 2.4%; AFL, 17.9%; AT, 22.2%, P = .005). The best AUC corresponded to the forced expiratory flow between 25% and 75% of vital capacity (FEF25-75): 0.787; 95% confidence interval, 0.600-0.973. Other significant AUCs were those for the reactance area (AX), forced expiratory volume in the first second (FEV1), the post-BD change in forced vital capacity (FVC), and the FEV1/FVC ratio. All of the variables had a low sensitivity for prediction of SAEs. The AT phenotype had the best specificity (93.8%; 95% CI, 87.9-97.0), but the positive and negative likelihood ratios were both significant only for the FEF25-75. In the multivariate analysis, only some spirometry parameters were significative for prediction of SAEs (AT phenotype, FEF25-75 and FEV1/FVC). CONCLUSIONS: Spirometry performed better than RO for prediction of SAEs in the medium term in schoolchildren with asthma.

Asthma control in children, socioeconomic inequality and health care.

INTRODUCTION: Socioeconomic inequality (SEI) can adversely affect asthma control. The aim of this study was to establish the association of SEI with asthma control in children and caregiver quality of life. METHODS: We assessed socioeconomic status based on the area of residence, according to the at risk of poverty rate (ARPR). After stratifying the paediatric population of Castilla y León (Spain) in ARPR tertiles, we selected participants by stratified random sampling, and identified children with asthma aged 6-14 years from the health records of primary care centres. We collected data through questionnaires completed by parents. The primary outcomes were asthma control and caregiver quality of life. We assessed their association with SEI, health care quality measures and individual factors (such as parental educational attainment) by means of multivariate regression models. RESULT: The ARPR tertile was not associated with asthma control, quality of life or health care quality. A medium or high maternal educational attainment was associated with a lower risk of making an unscheduled or urgent visit (OR = .50; 95% CI, .27-.95; P = .034) and paternal educational attainment was associated with a lower risk of uncontrolled asthma (OR = 0.51; 95% CI, .28-.94; P = .030). CONCLUSION: In the sample under study, SEI assessed at the local level was not associated with asthma control in children. Other factors, such as parental educational attainment, may have a protective effect.

Spirometry and respiratory oscillometry: Feasibility and concordance in schoolchildren with asthma.

OBJECTIVE: The purpose of this study was to describe the feasibility of respiratory oscillometry (RO) in schoolchildren with asthma, and the concordance of its results with those of spirometry, to determine its clinical usefulness. METHODS: RO and spirometry were performed in 154 children (6 to 14-year-old) with asthma, following strict quality criteria for the tests. Their feasibility (probability of valid test, time of execution, number of maneuvers needed to achieve a valid test, and perceived difficulty) was compared. The factors that influence feasibility were analyzed with multivariate methods. FEV1, FEV1/FVC, FVC and FEF25-75 for spirometry, and R5, AX and R5-19 for RO, were converted into z-scores and their concordance was investigated through intraclass correlation coefficients (ICC) and kappa indices for normal/abnormal values. RESULTS: There were no differences in the probability of obtaining a valid RO or spirometry (83.1% vs. 81.8%, p = 0.868). RO required a lower number of maneuvers [mean (SD) 4.2 (1.8) versus 6.0 (1.6), p < 0.001] and less execution time [5.1 (2.7) versus 7.6 (2.4) minutes, p < 0.001], and patients considered it less difficult. Age increased the probability of obtaining valid RO and spirometry. The concordance of results between RO and spirometry was low, and only between zFEV1 and zAX could it be considered moderate (ICC = 0.412, kappa = 0.427). CONCLUSION: RO and spirometry are feasible in children with asthma. RO has some practical advantages, but the concordance of its results with spirometry is low.