Feasibility of measuring lung function with the forced oscillation technique in an epidemiological study

Background: forced oscillation technique (FOT) is a non–invasive method used to assess respiratory mechanics. The main parameters, resistance (R) and reactance (X); inspiratory (R insp ), expiratory (R exp ) and total (R tot ); can be obtained at different frequencies and with a minimal cooperation. This makes FOT fit for epidemiological studies. Aim: to investigate reproducibility and acceptability of FOT in assessing the respiratory function in school-aged children and adolescents. Methods: 159 subjects have been studied by FOT, 100 from primary and 59 from high school. The measurements were considered of high quality (HQ) if the standard deviations (SD) of R insp , R exp and R tot were less than 0,7 and the ratio between SD and each R parameter was less than 0,3. If just one condition was met, the measurement was considered acceptable (AQ). Results: HQ and AQ measurements were obtained respectively from 81% and 98% of subjects. Learning and age effect on the variance was considered. The best reproducibility was achieved at 5 Hz in 151 children. The distribution of the results is reported in the table. Conclusions: measurements obtained by FOT have proved to have high acceptability and good reproducibility. This confirms that FOT can be efficiently used in epidemiological studies, particularly in school age.