Non-linear FRC measurement bias due to decreased pre-capillary dead space.

<p>Bland Altmann plot of functional residual capacity (FRC) determined at lower pre-capillary dead space setting (19 mL instead of 24 mL) minus baseline FRC versus mean of both FRC. Black circles represent children with CF, grey circles former preterm and open circles healthy children. Solid line represent mean difference (0.45%), dotted lines represent upper (0.71%) and lower (0.18%) limits of agreement.</p

Effect size of the change in LCI after reanalysis with different signal delay times.

<p>The table shows mean <i>±</i> SD [range] LCI after reanalysis of the tests with changed signal delay times, mean ± SD change in percentage of standard LCI, number of children with a change between 5–10% and children with >10% change of standard LCI. Of note, for simultaneous signal changes using similar time steps, delays between O₂ and CO₂ sensor were kept constant.</p><p>Effect size of the change in LCI after reanalysis with different signal delay times.</p

Change of N₂MBW results after reanalysis with different signal delay times.

<p>Change of N₂MBW test results of 30 children after simulation with changed signal delay times. Results of standard N₂MBW test were compared to the test with changed setting parameter by Wilcoxon signed-rank test and marked as follows: ↓↓ difference of p < 0.001, ↓ p < 0.01, (↓) p < 0.05, ↔ no significant change. Of note, for simultaneous signal changes using similar time steps, delays between O₂ and CO₂ sensor were kept constant.</p><p>Change of N₂MBW results after reanalysis with different signal delay times.</p

Effect size of the change in LCI after reanalysis with different apparatus dead space.

<p>The table shows mean <i>±</i> SD [range] LCI after reanalysis of the tests with changed apparatus dead space, mean <i>±</i> SD change in percentage of standard LCI, number of children with a change between 5–10% and children with >10% change of standard LCI.</p><p>Effect size of the change in LCI after reanalysis with different apparatus dead space.</p

LCI measurement bias due to decreased ambient pressure settings.

<p>Bland Altmann plot of lung clearence index (LCI) determined at lower ambient pressure setting (960 kPa instead of 980 kPa) minus baseline LCI versus mean of both LCI. Black circles represent children with CF, grey circles former preterm and open circles healthy children. Solid line represent mean difference (0.0034), dotted lines represent upper (0.0066) and lower (0.0002) limits of agreement.</p

Summary of the impact of different software settings on LCI of N₂MBW.

<p>Overview of impact on LCI after change of software settings. High quality N₂MBW tests of 30 children with different lung disease were reanalyzed with changed software settings. Several parameters were changed according to four sectors, environmental conditions (e.g. ambient temperature), setup parameter (apparatus dead space), software algorithm (e.g. O₂ response-time correction), and flow-gas signal delay times. Because of the uniformity of change statistical significance might be reached over the study population without clinical relevance (defined as >10% change of baseline LCI for the individual measurement; and for the change in software setting if >10% of all children showed such a LCI change >10%).</p><p>Summary of the impact of different software settings on LCI of N₂MBW.</p

Baseline settings per patient group.

<p>Data are given as mean ± SD, [range] and (95% CI). Baseline settings per patient group. Individual delay times per file, averaged delay times per dead space reducer set used as baseline, and individual changes for O₂ and CO₂ delay.</p><p>*For logistic reasons at the time of measurement in two children of the preterm group and two children of the CF group we had to use set 3 instead of 2.</p><p>Baseline settings per patient group.</p

Change of N₂MBW results after reanalysis with different signal processing and detection limits.

<p>Change of N₂MBW test results of 30 children after simulation with changed default algorithms for signal correction. Results of standard N₂MBW test were compared to the test with changed setting parameter by Wilcoxon signed-rank test and marked as follows: ↓↓ difference of p < 0.001, ↓ p < 0.01, (↓)p < 0.05, ↔ no significant change, ↔↔ no change at all.</p><p>Change of N₂MBW results after reanalysis with different signal processing and detection limits.</p

Change of N₂MBW results after reanalysis with different apparatus dead space.

<p>Change of N₂MBW test results of 30 children after simulation with changed apparatus dead space (pre-capillary dead space (precap DS), post-capillary DS (postcap DS) and both). Results of standard N₂MBW test were compared to the test with changed setting parameter by Wilcoxon signed-rank test and marked as follows: ↓↓ difference of p < 0.001, ↓ p < 0.01, (↓)p < 0.05, ↔ no significant change.</p><p>Change of N₂MBW results after reanalysis with different apparatus dead space.</p

Non-linear FRC measurement bias due to decreased pre-capillary dead space.

<p>Bland Altmann plot of functional residual capacity (FRC) determined at lower pre-capillary dead space setting (19 mL instead of 24 mL) minus baseline FRC versus mean of both FRC. Black circles represent children with CF, grey circles former preterm and open circles healthy children. Solid line represent mean difference (0.45%), dotted lines represent upper (0.71%) and lower (0.18%) limits of agreement.</p