Is forced oscillation technique the next respiratory function test of choice in childhood asthma

Table 1 Fifteen minutes’ repeatability of Forced oscillation technique in healthy children

Author	Year	n	Rrs	Xrs
Hall et al[13]	2007	58; field	~2 or ~ 30%	1.2 - 1.7
Malmberg et al[18]	2002	19; placebo	1.1 or ~ 12%	1.3
Klug et al[16]	1998	120	2.6 or ~ 20%	2

Rrs: Respiratory system resistance; Xrs: Respiratory system reactance) in hPa/s per L.

Table 2 Populations of healthy children studied using forced oscillation technique since 2005, adopted and modified from

Ref.	Year of publication	Ethnic group - Country of study	Subject number	Age in years	Height (cm)	Reported prediction equation variables
Frei et al[35]	2005	Caucasian - Canadian	222	3-10	90-155	Rrs at 5-35 Hz Xrs at 5-35 Hz Fres, AX
Dencker et al[36]	2006	Caucasian - Scandinavian	360	2-11	90-162	Rrs at 5-20 Hz Xrs at 5-20 Hz Fres
Amra et al[37]	2008	Asian - Iranian	509	5-18	127-197	Rrs at 5-25 Hz Xrs at 5-25 Hz
Nowowiejska et al[38]	2008	Caucasian - Polish	626	3-18	95-193	Rrs at 5-35 Hz Xrs at 5-35 Fres
Vu et al[39]	2008	Asian - Vietnamese	175	6-11	111-154	Rrs at 8 Hz Xrs at 8 Hz
Vu et al[40]	2010	Asian - Vietnamese	95	6-11	111-134	Rrs at 8 Hz Xrs at 8 Hz
Calogero et al[41]	2010	Italian	163	2-6	101-114	Rrs at 6-10 Hz Xrs at 6-10 Hz
Park et al[42]	2011	Korean	133	3-6	95-121	Rrs at 5, 10 Xrs at 5, 10 RF, AX
Calogero et al[43]	2013	Caucasian Italian and Australian	760	2-13	90-160	Rrs at 6, 8, 10 Hz Xrs at 6, 8, 10 Hz Fres, AX
Shackleton et al[44]	2013	Mexican	584	3-5	87-119	Rrs at 6 and 8 Hz Xrs at 6 and 8 Hz
Hagiwara et al[46]	2014	Japanese	537	6-15	111-174	Rrs at 5 and 20 Hz Rrs5-20

IOS: Impulse oscillation system; Rrs: Respiratory system resistance; Xrs: Respiratory system reactance) in hPa/s per L; Fres: Resonant frequency; RF: Resonant frequency; AX: Area under the Xrs curve from 5 Hz to Fres; MF: Multi-frequency system; Fdep: Frequency dependence of Rrs between 4–24 Hz; SF: Single frequency system.

Table 3 Reported bronchodilator responsiveness in young healthy and wheezy children using forced oscillation technique since 2005

Ref.	Ethnic group age, yr	n	Variable	Dose	Waiting time (n)	Absolute BDR	Relative BDR, (%)
Thamrin et al[53], 2007	Healthy Caucasian (3-7)	78	Rrs 6,8,10 Xrs 6,8,10	Salbutamol 600 mg	15	Rrs 6 -35.0, -3.1 Rrs 8 -35.0, -4.4 Rrs 10 -32.3, -3.7 Xrs 6 -0.27, 1.66 Xrs 8 - 0.04, 1.82 Xrs 10 -0.00, 2.03	Rrs 6: 42% Rrs 8: 37% Rrs 10: 39% Xrs 6: 61% Xrs 8: 67% Xrs 10: 63%
Thamrin et al[53], 2007	Asthmatics Caucasian (3-7)	57	Rrs 6, 8, 10 Xrs 6, 8, 10	Salbutamol 600 µg	15	Rrs 6 -37.0, 8.8 Rrs8 -33.1, 9.7 Rrs 10 -33.4, 4.5 Xrs 6 -0.21, 2.30 Xrs 8 -0.13, 2.47 Xrs 10 -0.12, 2.22	Rrs 6: 42% Rrs 8: 37% Rrs 10: 39% Xrs 6: 61% Xrs 8: 67% Xrs 10: 63%
Lan Vu et al[39], 2008	Healthy Vietnamese (6–11)	175	Rrs 8 Hz Xrs 8 Hz	Salbutamol 200 µg	5	Rrs 8 -11.8,13.4 Xrs 8 4.09, - 5.78	Rrs 8: 38% Xrs 8: 16%
Lan Vu et al[40], 2010	Asthmatic Vietnamese (6-10)	103	Rrs 8 Hz Xrs 8 Hz	Salbutamol 200 µg	5	--	Rrs 8: 13% Xrs: 32%
Oostveen et al[55], 2010	Asthmatic Belgian -4	313	Rrs 4	Salbutamol 200 µg	15	--	Rrs 4: 22% AX: 15.77%
Calogero et al[41], 2010	Healthy Italian (3-6)	163	Rrs 8 Xrs8	Salbutamol 200 µg	15	--	Rrs 8: 35% Xrs 8: 34%-61%
LEE et al[57], 2012	Healthy Korean	161	Rrs 5, 10, 15, 20, 25, 35 Xrs 5, 10, 15, 20, 25, 35	Salbutamol 200 µg	15	Rrs 5 -0.127 Rrs 10 -0.098 Rrs 15 -0.073 Rrs 20 -0.056 Rrs 25 -0.056 Rrs 35 -0.057 Xrs 5 0.062 Xrs 10 0.057 Xrs 15 0.059 Xrs 20 0.044 Xrs 25 0.033 Xrs 35 0.054 Fres -2.167	Rrs 5: 11.8 Rrs 10: 10.8 Rrs 15: 8.7 Rrs 20: 6.972 Rrs 25: 7.029 Rrs 35: 6.095 Xrs 5: 13.474 Xrs 10: 25.946 Fres: 10.457
Calogero et al[43], 2013	Healthy Australian and Italian (2-16)	502	Rrs 6, 8, 10 Xrs 6, 8, 10 Fres, AX	Salbutamol 200 µg	15	Rrs 6 -2.9 Rrs 8 -2.74 Rrs 10 -2.39 Xrs 6 -1.80 Xrs 8 - 1.93 Xrs 10 -1.90 AX -33 Fres -12	Rrs 6: 34 Rrs 8: 32 Rrs 10: 31 Xrs 6: 50 Xrs 8: 65 Xrs 10: 74 AX: 81 Fres: 47

BDR: Bronchodilator responsiveness; Rrs: Respiratory system resistance; Xrs: Respiratory system reactance in hPa/s per L; Fres: Resonant frequency; AX: Area under the Xrs curve from 5 Hz to Fres; MF: Multi-frequency system; Fdep: Frequency dependence of Rrs between 4-24 Hz.