Correlation Study Of PEF And Prognosis Index Of Airflow Obstruction In COPD

ObjectiveTo explore peak expiratory flow （PEF） assessment of the severity ofairflow obstruction and FEV1as severity classification of COPD and itsCorrelation and clinical significance.MethodClinical data from outpatient of60cases of patients with COPD and60cases of healthy people, during June2008to January2013in Ningxia medicaluniversity general hospital， a retrospective collection of respiratoryparameters，such as FVC, FEV1, FEV1/FVC,PEF，analysised the correlationof FEV1and PEF， PEF screening airflow obstruction of sensitivity,specificity， accuracy and the ROC curve of PEF diagnosis of the airflowobstruction in COPD.Results1.60patients with COPD, correlation coefficient (r) of FEV1and PEF was0.815(P=0.000<0.01).60cases of the control group, correlation coefficient(r) of FEV1and PEF was0.306(P=0.017<0.05).The COPD group and controlgroup, FEV1and PEF showed a linear positive correlation (P<0.05), andcorrelation coefficient of FEV1and PEF in COPD group was obviously higherthan that of control group.2.In COPD group, patients with mild airflow obstruction （GOLD1）,correlation coefficient (r) of FEV1and PEF was-1(P=0.117﹥0.05)；38patients with moderate airflow obstruction（GOLD2）, correlation coefficient (r) of FEV1and PEF was0.315(P=0.006<0.01);11patients with severeairflow obstruction （GOLD3）, correlation coefficient (r) of FEV1and PEFwas0.624(P=0.008<0.01);8patients with very severe airflow obstruction（GOLD4）, correlation coefficient (r) of FEV1and PEF was0.830(P=0.005<0.01).3.In COPD group,42patients with smoking, correlation coefficient (r) ofFEV1and PEF was0.732(P=0.000<0.01);18patients with no smokingcorrelation coefficient (r) of FEV1and PEF was0.420(P=0.016<0.05).4.PEF analysising sensitivity, specificity and accuracy in screening ofmild-extremely severe airflow obstruction, we obtained that PEF<70%predcould sift through81.67%airflow obstruction confirmed by pulmonaryfunction examination; PEF<70%pred could sift through85.9%moderate tovery severe airflow obstruction confirmed by pulmonary function examination.PEF<60%pred could screen100%severe to extremely severe airflowlimitation.5.Using PEF as the degree of airflow obstruction of diagnostic test, thearea under the ROC curve was0.912.Conclusion1.PEF and FEV1have good correlation in COPD patients.2.In COPD group,the more serious the degree of airflow obstruction ofCOPD, the correlation is better; the correlation of smoking is stronger thanthat of nonsmoking.3.PEF used as an auxiliary index for screening airflow obstruction inCOPD, has certain clinical feasibility.