Within-subject variability of the interrupter technique
| Population measured under field conditions | Population measured under standardised conditions | ||
|---|---|---|---|
| Short term variability | Long term variability | Long term variability | |
| Rint=interrupter resistance; SDw=within-subject standard deviation. | |||
| *Z scores calculated as (measured Rint – predicted Rint)/(RSD of the reference population). Predicted Rint values calculated based on regression equation by Merkus et al.1 | |||
| Mean (SD), range baseline Rint (kPa/l/s) | 0.99 (0.22) (0.60–1.41) | 0.97 (0.20) (0.60–1.29) | 0.85 (0.21) (0.55–1.31) |
| Mean baseline Rint Z score* | 0.59 | 0.41 | 0.11 |
| SDw (kPa/l/s) | 0.10 | 0.13 | 0.10 |