Disagreement between common measures of asthma control in children

Abstract

BACKGROUND: Asthma is a worldwide problem. It cannot be prevented or cured, but it is possible, at least in principle, to control asthma with modern management. Control usually is assessed by history of symptoms, physical examination, and measurement of lung function. A practical problem is that these measures of control may not be in agreement. The aim of this study was to describe agreement among different measures of asthma control in children. METHODS: A prospective sequential sample of children aged 4 to 11 years with atopic asthma attending a routine follow-up evaluation were studied. Patients were assessed with the following four steps: (1) fraction of exhaled nitric oxide (F ENO ), (2) spirometry, (3) Childhood Asthma Control Test (cACT), and (4) conventional clinical assessment by a pediatrician. The outcome for each test was coded as controlled or uncontrolled asthma. Agreement among measures was examined by cross-tabulation and k statistics. RESULTS: Eighty children were enrolled, and nine were excluded. Mean F ENO in pediatricianjudged uncontrolled asthma was double that of controlled asthma (37 parts per billion vs 15 parts per billion, P , .005). There was disagreement among measures of control. Spirometric indices revealed some correlation, but of the unrelated comparisons, those that agreed with each other most often (69%) were clinical assessment by the pediatrician and the cACT. Worst agreement was noted for F ENO and cACT (49.3%). CONCLUSION: Overall, different measures to assess control of asthma showed a lack of agreement for all comparisons in this study.