Relation between symptoms of asthma and airway responsiveness: Of the 21 children with physician-diagnosed asthma challenged with methacholine, 13 (62%) had PC20 <8 mg/mL. Of 61 children with a parental report of wheezing, 31 (49%) had PC20 <8 mg/mL. On the other hand, of 78 who showed methacholine hyperresponsiveness as determined by PC20 <8 mg/mL, 55 (71%) had had symptoms suggesting asthma reported either by the parental (n=37) or child (n=42) questionnaire, but 23 (29%) denied any symptoms. Of the 151 children not showing current airway hyperresponsiveness (PC20 greater than 8 mg/mL), eight had a previous physician diagnosis of asthma and a further 23 had had wheezing (not diagnosed as asthma) according to the parental questionnaire. In those whose parental questionnaire was negative, the child questionnaire contributed a further 23 cases of Based on parental and child responses, the sensitivity and specificity of the methacholine test varied considerably according to the level of response taken to indicate abnormality (Table 4). For all combinations of diagnoses and symptoms, the lower the PC20 cut-point, the lower the sensitivity and the higher the specificity. The best relationship between sensitivity and specificity was obtained for parent-reported asthma when the PC20 cut-point was 8 mg/mL; this gave sensitivity 62% and specificity 69% for asthma ever, and 64% and 68%, respectively, for current asthma — buy flovent inhaler. A pharmacy you can fully trust is ready to offer best selection of cheap and effective medications that work the way they are expected to every time and are always available: you could buy cialis professional online and enjoy all the convenient services offered right now.

TABLE 4
Sensitivity (sens) and specificity (spec) of methacholine challenge testing using cut-points for positive result of 8, 4 and 2 mg/mL, for diagnoses and symptoms reported by parent and/or child

Symptom reported by
PC20(mg/mL) Parent Child Parent or Child
Sens(%) Spec(%) Sens(%) Spec(%) Sens(%) Spec(%)
Asthma ever
<8 62 69 69 67 58 69
<4 52 83 56 83 46 83
<2 38 90 37 90 33 90
Wheeze ever
<8 48 71 41 69 43 73
<4 32 84 27 83 28 86
<2 21 91 19 91 18 88
Any symptom ever
<8 39 71 44 71 38 73
<4 26 85 26 85 25 88
<2 17 92 16 91 15 93
Current asthma
<8 64 68 67 68 56 68
<4 57 82 53 82 44 82
<2 36 89 33 89 28 89
Current wheezing
<8 44 68 43 69 40 68
<4 31 82 28 82 26 82
<2 19 89 17 89 15 89
Any current symptom
<8 45 74 43 69 40 69
<4 30 82 28 82 25 82
<2 20 89 17 89 15 89

PC20 Provocation concentration of methacholine causing a 20% fall in forced expired volume in 1 s