Correlation Between Childhood Asthma Control Test And Lung Function Of Asthmatic Children

Objective:To investigate the relationship among childhood asthma control test and pulmonary ventilation function and airway hyperresponsiveness in asthmatic children.Methods:Asthmatic children aged from4to11years were recruited during their regular visit to Children’s Hospital of Chongqing Medical University, between October2009to May2010.Children and their parents were asked to complete the Chinese version of the C-ACT with the help of the specialist physician. Then, the lung function was measured. Build database with children’s essential information, C-ACT score and lung function. The relationship between the C-ACT score and the measured lung function parameters (FEV1%, PEF%, MMEF%, PC20) were analyzed using the SPSS17.0.Results:1. General information Totally324asthmatic children were enrolled with the mean age of7.1years±2.3SD, including214boys (66%) and110girls (34%).153(47.2%) children aged from4to6years, and171(52.8%) aged from7to11years old. According to C-ACT score,17.9%of the participants were ’uncontrolled"(C-ACT≤19),27.8%were " partly controlled "(20≤C-ACT),whereas54.3%were " completely controlled "(C-ACT≥23).2. Correlation coefficient between C-ACT score and pulmonary ventilation functionOf all the children,Pearson’s correlation coefficient revealed positive correlation between C-ACT score and FEV1%(r=0.255,P<0.01), and PEF%(r=0.344, P<0.01), and MMEF%(r=0.265, P<0.01),respectively. For elder participants who were aged from7to llyears,their C-ACT score demonstrated modest correlations with FEV1%(r=0.339,P=0.01), and PEF%(r=0.382,P<0.01), and MMEF%(r=0.375,P<0.01),respectively. In contrast, there was no relationship between the C-ACT score and pulmonary ventilation parameter. For the patients who have suffered from Upper respiratory tract infection (URI)4weeks before the doctor, their C-ACT score demonstrated weak correlations with FEV1%(r=0.203, P<0.05), and PEF%(r=0.282,P<0.05),andMMEF%(r=0.217,P<0.05), respectively. For the patients who have not suffered from URI4weeks before the doctor, their C-ACT score demonstrated weak correlations with FEV1%(r=0.249, P <0.01), and modest correlation with PEF% (r=0.411,P<0.01),and MMEF%(r=0.275,P<0.01), respectively. When wipe off the younger patients who were less than7years and the children who have suffered from URI4weeks before the doctor, there were58participants left, and their C-ACT score demonstrated modest correlations with FEV1%(r=0.415, P<0.01), and good correlations with PEF%(r=0.518,P<0.01),and modest correlations with MMEF%(r=0.394,P <0.01)3. Relationship between Airway hyperresponsiveness, C-ACT score and pulmonary ventilation functionThe patients were divided into4groups on the degree of airway hyperresponsiveness,1) severe group (PC20=0.5mg/ml),2) moderate group (PC20=2mg/ml),3) mild group (PC20=8mg/ml),4) minimal group (PC20=16mg/ml). Interblock difference were found in C-ACT、FEV1%、 MMEF%(P<0.05).Further analysis demonstrated that, for clinical score, the minimal group were obviously higher than severe group(P<0.001),but there were no difference between mild group and moderate group. For MMEF%, there were significant difference among severe group, moderate group and mild group (P<0.05),but for FEVi%and PEF%, severe group was the only group that obviously lower than other groups.4. Influence of suffering from upper respiratory tract infection4weeks before the doctor on C-ACT and lung functionAll the parameters of the group who suffered from URI4weeks before the doctor were lower than another group. Among the index, C-ACT (21.5±2.3VS.23.7±2.5)、PEF%(87.7±17.3VS.93.5±15.9)、 MMEF%(83.5±24.3VS.92.8±23.4)、PC20(4.9±5.5VS.7.1±5.9) differed significantly in the two groups.5. Consistency of C-ACT and pulmonary ventilation functionOf all children, there were16cases who’s C-ACT<19&FEV1%<80%, and225cases C-ACT>20&FEV1%≥80%, and39cases C-ACT≤19&FEV1%≥80%, and44cases C-ACT>20&FEV1%≤80%. The consistency of C-ACT score pulmonary ventilation function was74.4%. After adjustment for ages and suffering from URI4weeks before the doctor, this index was as high as91.4%.Conclusion:1. Suffering from URI4weeks before the doctor and less than7years old were the two factors that influenced the correlation. Get rid of the two factors, C-ACT score and pulmonary ventilation function demonstrated good correlation.2. C-ACT score could distinguish severe AHR group and minimal AHR group from asthmatic children.