Baseline characteristics of the study population.

Background
Oscillometry devices (also termed forced oscillation technique) devices such as MasterScreen-IOS® (Jaeger, Hochberg, Germany) and MostGraph-01® (Chest, Tokyo, Japan) are useful for obtaining physiological assessments in patients with obstructive lung diseases, including asthma. However, as oscillometry measurements have not been fully compared between MasterScreen-IOS® and MostGraph-01® in patients with asthma, it is unknown whether there are differences in the measurements between the devices. This study aimed to determine whether there is any difference in oscillometry measurements obtained using the two devices in patients with asthma.
Methods
Oscillometry measurements obtained using MasterScreen-IOS® and MostGraph-01® were retrospectively evaluated in 95 patients with asthma at Juntendo University Hospital between October 2009 and November 2009.
Results
There was a strong positive correlation in the measurements between the two devices. However, the values of R5, R20, ALX and Fres were lower when measured with MostGraph-01® than with MasterScreen-IOS®, and vice versa for the values of X5. The results were used in correction equations to convert oscillometry parameters measured using MasterScreen-IOS® to those measured using MostGraph-01®.
Conclusions
To our knowledge, this is the first report to compare MostGraph-01® and MasterScreen-IOS® devices using practical clinical data obtained in patients with asthma. The values obtained by both devices can be interpreted in a similar way, although there is slight variation. The conversion equations produced in this study may assist to compare the oscillometry measurements obtained by each of the two devices.