%0 Journal Article
%T Relation of changes in peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV1) during bronchoconstriction.
%A Csonka LL
%A Tikkakoski A
%A Vuotari L
%A Karjalainen J
%A Lehtimäki L
%J Clin Physiol Funct Imaging
%V 0
%N 0
%D 2024 Jun 22
%M 38923340
%F 2.121
%R 10.1111/cpf.12898
%X Diagnosis of asthma can be confirmed based on variability in peak expiratory flow (PEF) or changes in forced expiratory volume in 1 s (FEV1) measured with spirometry. Our aim was to use methacholine challenge as a model of induced airway obstruction to assess how well relative changes in PEF reflect airway obstruction in comparison to relative changes in FEV1. We retrospectively studied 878 patients who completed a methacholine challenge test. To assess congruency along with differences between relative changes in FEV1 and PEF during airway obstruction, a regression analysis was performed, and a Bland & Altman plot was constructed. ROC analysis, sensitivity, specificity, positive and negative predictive values and κ-coefficient were used to analyze how decrease in PEF predicts decrease of 10% or 15% in FEV1. The relative change in PEF was on average less than the relative change in FEV1. In the ROC analysis areas under the curve were 0.844 and 0.893 for PEF decrease to predict a 10% and 15% decrease in FEV1, respectively. The agreement between changes in PEF and FEV1 varied from fair to moderate. Airway obstruction detected by change in PEF was false in about 40% of cases when compared to change in FEV1. Change in PEF is not a very accurate measure of airway obstruction when compared to change in FEV1. Replacing peak flow metre with a handheld spirometer might improve diagnostic accuracy of home monitoring in asthma.