Utility of measuring FEV_0.75/FVC ratio in preschoolers with uncontrolled wheezing disorder

Abstract

Uncontrolled wheezing disorder is common in preschoolers and disease control assessment is challenging as parents frequently overestimate the extent to which their child's disease is controlled. This is the first study of forced expiratory volume in t s (FEVt)/forced vital capacity (FVC) ratio measurements (i.e. FEV1/FVC, FEV0.75/FVC and FEV0.5/FVC) in wheezy preschoolers in relation to disease control. Our objective was to evaluate whether FEVt/FVC ratios less than the lower limit of normal (LLN; z-score <-1.64) were associated with uncontrolled wheezing disorder in preschoolers.Valid FVC, FEV1, FEV0.75 and FEV0.5 values were obtained in 92 healthy and 125 wheezy (62% uncontrolled) children (3-5 years). Associations between spirometry value <LLN, disease classification (healthy/wheezy) and disease control classifications (controlled/uncontrolled disease) were estimated using logistic regression.FEV0.75/FVC or FEV0.5/FVC ratios <LLN were associated with wheezing disorder (OR 9.78, 95% CI 3.70-25.88 and OR 6.64, 95% CI 2.24-19.66; all p<0.001). Only an FEV0.75/FVC ratio <LLN was associated with uncontrolled wheezing disorder (OR 2.53, 95% CI 1.12-5.68; p=0.025).FEV0.75/FVC ratio is a useful surrogate outcome index to evaluate the control of the wheezing disease of preschoolers.

Reference Values and Related Factors for Peak Expiratory Flow in Middle-Aged and Elderly Chinese

“…In addition, the cutoff point was defined as 2 SD below the mean value from subjects under the age of 65 years. The diagnostic criteria from fixed value are very practical in clinical practice ( 33 ).…”

Raised-Volume Forced Expiratory Flow-Volume Curve in Healthy Taiwanese Infants

“…Therefore, studies have advocated the use of FEV 0.75 , FEV 0.5 , and FEV 0.4 to investigate airway function in young children and infants 22–24 . Although FEV 1 /FVC has been considered more sensitive for monitoring airflow limitation 15 , FEV 0.5 /FVC (or FEV 0.75 /FVC), instead of FEV 1 /FVC, appears to be a more suitable proxy index for detecting and monitoring airway function in very young children 25 . However, the value indicating airflow limitation depends highly on age when FEV 1 /FVC is used as an index.…”

“…The RVRTC technique was performed in accordance with the ATS/ERS guidelines 5, 25 . The jacket inflation pressure was set to match the value of the previous forced tidal expiration.…”

Reference Values and Related Factors for Peak Expiratory Flow in Middle-aged and Elderly Chinese

“…In addition, cut-off point was de ned as 2 SD below mean value from subjects under 65 years. a diagnose criteria from xed value are very practical in clinical practice [32].…”