Table 4.
Validity analyses of the Metamax 3B data against the Douglas bag (primary criterion) during parallel data collection at rest, moderate, and vigorous cycle exercise
| Variable | Activity level | Bland–Altman bias (L min−1) | % difference | Inter-device TEM (%) |
|---|---|---|---|---|
| Mean ± SD (95% LOA) | Mean ± SD | Mean | ||
| V E (BTPS, L min−1) | Rest | −0.79 ± 1.62 (2.45, −4.04) | −8.8 ± 19.3 | 17.0 |
| Moderate | 0.72 ± 2.76 (6.24, −4.80) | 1.5 ± 9.8 | 7.0 | |
| Vigorous | 0.25 ± 10.02 (20.28, −19.79) | 2.2 ± 13.3 | 9.7 | |
| VO2 (STPD, L min−1) | Rest | 0.03 ± 0.05 (0.14, −0.07) | 10.6 ± 19.3 | 14.0 |
| Moderate | 0.12 ± 0.14** (0.41, −0.16) | 9.7 ± 13.2** | 10.9 | |
| Vigorous | 0.27 ± 0.16** (0.59, −0.05) | 11.8 ± 7.6** | 9.4 | |
| VCO2 (STPD, L min−1) | Rest | 0.04 ± 0.05 (0.14, −0.06) | 17.3 ± 21.8 | 18.0 |
| Moderate | 0.14 ± 0.11** (0.36, −0.08) | 12.5 ± 9.8** | 10.6 | |
| Vigorous | 0.39 ± 0.23** (0.85, −0.07) | 17.4 ± 8.1** | 12.8 |
Data shown from Bland–Altman analyses (mean ± SD of bias, and 95% limits of agreement, LOA), percentage differences between means, and the inter-device TEM (%)
Bias and differences computed for data calculated from the Metamax 3B–Douglas bag
TEM% technical error of measurement expressed as percentage of mean value
** Metamax 3B significantly different to Douglas bag measurements (ANOVA, p < 0.01)