TY - JOUR T1 - Newly developed multiple-breath washout reference equations from the CHILD Cohort Study: implications of poorly fitting equations JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00301-2020 VL - 7 IS - 1 SP - 00301-2020 AU - Zihang Lu AU - Ruixue Dai AU - Krzysztof Kowalik AU - Aimee Dubeau AU - Diana L. Lefebvre AU - Susan Balkovec AU - Allan B. Becker AU - Piush J. Mandhane AU - Stuart E. Turvey AU - Wendy Lou AU - Felix Ratjen AU - Theo J. Moraes AU - Malcolm R. Sears AU - Per M. Gustafsson AU - Padmaja Subbarao Y1 - 2021/01/01 UR - http://openres.ersjournals.com/content/7/1/00301-2020.abstract N2 - The multiple-breath washout (MBW) test allows for the measurement of lung volumes, ventilation homogeneity and gas clearance curves during tidal breathing [1]. Lung clearance index (LCI), the most commonly reported parameter from the MBW test, is a marker of ventilation inhomogeneity and is associated with early lung disease. LCI is defined as the cumulative expired volume divided by the functional residual capacity (FRC). The currently accepted reference equation for LCI measured using sulfur hexafluoride (SF6) shows a non-linear decrease as age and height increase, with height as an independent predictor from infancy to school-age [2]. In contrast, FRC shows a non-linear increase in FRC as age and height increase with males having higher measured FRC compared to female subjects.Using inappropriate reference equations would provide incorrect estimate of z-scores, which would cause misdiagnosis. Appropriate representative normative reference data must be available to correctly interpret individual lung function results. https://bit.ly/3dcNZ5p ER -