TABLE 3.

Summary of findings in eight individual studies reporting on oscillometry after haematopoietic stem cell transplant (HSCT)

Cohort	Summary of findings
	Spirometry	Oscillometry
Paediatric subjects
Jayasuriya et al. [47, 60, 71, 77, 78]	FEV1 was abnormal in 5, FEF25–75 in 4	Median Rrs at 6 Hz 6.73 (range: 3.05–8.00) and Xrs −2.10 (range: −1.13–2.71)
Wong et al. [54], Hardaker et al. [80–82] and Robinson et al. [83]	cGHVD was associated with significant deterioration in FEV1 and FEF25–75 compared to those without cGVHD At 3 years post-HSCT, BOS 0p subjects (n=8) had FEV1 worse than subjects unaffected by BOS 0p/BOS that approached significance	cGVHD: significant increases in Xrs at 5 Hz, AX and Fres as compared to subjects without cGVHD BOS was associated with significant abnormality in Xrs at 5 Hz, AX and Fres; oscillometry abnormality was not detected prior to BOS diagnosis BOS 0p (n=8) subjects at 3 years post-HSCT significantly worse Xrs at 5 Hz as compared to subjects unaffected by BOS 0p/BOS and this approached significance for Fres
Adult subjects
De Giacomi et al. [45, 86, 87]	NA	Subjects with BO: mean±sd Xrs at 5 Hz was −1.84±2.26 and significantly worse than in controls (p=0.023)
Blin et al. [52]	NA	Xrs at 5 Hz, AX, Fres and R5-R20 were significantly worsened at time of BOS diagnosis as compared to first test; these indices did not change significantly earlier than FEV1
Lahzami et al. [48, 88] and Pechey et al. [89]	Initial testing (mean±sd or median (range)): FEV1 was 87±20% pred, FEV1/FVC 80 (45–89); FEV1 was independently associated with time post-HSCT Follow-up: no significant change in spirometry outcomes	Mean±sd or median (range): Rrs at 6 Hz 118±31% pred and Xrs at 6 Hz 153 (9–997)% pred Follow-up: median (range) Rrs was 103% pred (73–259) and Xrs was 172% pred (47–788) There was no significant change from initial testing
Barisione et al. 2012 [53, 91]	Baseline: spirometry and oscillometry were within normal range; mean±sd FEV1 was 3.67±0.74 L, FEV1/FVC was 0.81±0.06 Follow-up: there was no significant change in FEV1 or FEV1/FVC, which were mean±sd 3.54±0.75 L and mean±sd 0.81±0.15, respectively	Baseline: oscillometry was within normal range, Xrs at 5 Hz was −0.50±0.29 Follow-up: Xrs at 5 Hz became less negative (p=0.01) and was mean±sd −0.43±0.28
Schoeffel et al. [49, 59]	Baseline: mean±sd FEV1 was 105±13% pred, FEV1/FVC was normal Follow-up: FVC declined	Baseline: Rrs and Xrs at 6 Hz were normal in 91% Follow-up: no changes in Rrs and Xrs at 6 Hz BOS subjects: Rrs and Xrs at 6 Hz were all abnormal at time of BOS diagnosis; respiratory function at the visit prior to diagnosis was not different from baseline
Rutting et al. [51, 92]	Mean±sd FEV1/FVC ratio was 0.78±0.07	The median (IQR) within-session sd for Rrs and Xrs were 0.19 (0.10–0.40) and 0.11 (0.04–0.15), respectively; the median (IQR) between-visit sd for Rrs and Xrs were 0.26 (0.17–0.39) and 0.16 (0.10–0.26), respectively; within- and between-visit variability was greater than among healthy controls, but less than among COPD and asthma patients; worse FEV1/FVC was correlated with increased within- and between-visit variability; no absolute values of resistance or reactance are provided

AX: area under the reactance curve; BO: bronchiolitis obliterans; BOS: bronchiolitis obliterans syndrome; BOS 0p: BOS stage 0p; cGVHD: chronic graft-versus-host disease; FEF_25–75: forced expiratory flow between 25% and 75% of vital capacity; FEV₁: forced expiratory volume in the 1 s; F_res: resonant frequency; FVC: forced vital capacity; IQR: interquartile range; NA: not available; R5-R20: frequency dependence of resistance; R_rs: respiratory system resistance; X_rs: respiratory system reactance.