TABLE 1.
SUBJECT CHARACTERISTICS
| Subject (Sex) | Height (cm) | Weight (kg) | Age (yr) | PetCO2 at Rest (mm Hg) | HCVR Slope (L/min/mm Hg) | HCVR Intercept (mm Hg) | BDVAS Slope (%FS, mm Hg) | BDVAS Intercept (mm Hg) | Experience Relevant to Respiratory Testing |
| 1 (M) | 178 | 78 | 57 | 40 | 1.9 | 35.9 | 9.4 | 42.8 | Ph.D. in physiology, participating investigator |
| 3 (M) | 163 | 68 | 34 | 41 | 0.9 | 17 | 6.7 | 41.1 | College, no biology. Mouthpiece experience, breathing exercises in martial arts |
| 6 (M) | 188 | 80 | 21 | 42 | 2.0 | 38.2 | 6.9 | 41.3 | Some college, no biology, no controlled breathing experience |
| 11 (M) | 168 | 70 | 26 | 41 | 1.4 | 34.8 | 5.9 | 38.1 | College, biology major. No controlled breathing experience |
| 13 (M) | 183 | 77 | 20 | 45 | 1.4 | 40.6 | 5.3 | 50.3 | High school. Some scuba experience |
| 14 (F) | 183 | 64 | 23 | 39 | 1.2 | 33.7 | 10.7 | 38.7 | College (premed), emergency room aide |
| Mean | 177.2 | 72.8 | 30.2 | 41.3 | 1.5 | 33.4 | 7.5 | 42.1 | |
| Median | 180.5 | 73.5 | 24.5 | 41 | 1.4 | 35.3 | 6.8 | 41.2 | |
| SD | 9.7 | 6.4 | 14.1 | 2.1 | 0.4 | 8.4 | 2.1 | 4.4 | |
| Coefficient of variation | 5% | 9% | 47% | 5% | 29% | 25% | 28% | 10% |
Definition of abbreviations: BDVAS = Breathing Discomfort Visual Analog Scale; F = female; FS = full scale; HCVR = hypercapnic ventilatory response; M = male; PetCO2 = partial pressure of end-tidal carbon dioxide.
Note: Subject numbers were assigned in recruitment order; missing numbers reflect dropout as explained in text.