Table 2.
Tabulated comparison of reference SaO2 linear model coefficients (top row of coefficients; adapted from reference3) with linear model coefficients obtained from equivalent fits to daytime mean SpO2 (middle row of coefficients) and overnight SpO2 (bottom row of coefficients) using our data.
| Linear regression results for blood oxygen saturation: fit coefficients for reference model (MRef) | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model | R2 | SEE | Constant | Age (years) | Baro. Press. (mm Hg) | Weight (kg) | Sex (m = 1, f = 0) | Height (cm) |
| Reference SaO2 (Crapo et al.3) | 0.56 | 0.85 | 89.41 | −0.0362 | 0.0128 | −0.0159 | n.s. | n.s. |
| Daytime SpO2 | 0.23 | 1.13 | 89.25 (88.68, 89.83) [p < 1.0e−10] | −0.0309 (−0.0322, −0.0296) [p < 1.0e−10] | 0.0100 (0.0094, 0.0105) [p < 1.0e−10] | −0.0149 (−0.0157, −0.0140) [p < 1.0e−10] | −0.0168 (−0.0686, 0.0351) [p = 0.36] | 0.0123 (0.0098, 0.0149) [p < 1.0e−10] |
| Nocturnal SpO2 | 0.32 | 1.21 | 87.12 (86.50, 87.74) [p < 1.0e−10] | −0.0431 (−0.0445, −0.0417) [p < 1.0e−10] | 0.0140 (0.0134, 0.0146) [p < 1.0e−10] | −0.0182 (−0.0192, −0.0173) [p < 1.0e−10] | 0.1629 (0.1071, 0.2187) [p < 1.0e−10] | 0.0069 (0.0042, 0.0097) [p < 1.0e−10] |
Values in parentheses indicate 99.5% confidence intervals for fit coefficients. Values in brackets are regression coefficient p values, corresponding to two-sided t tests under the null hypothesis that the coefficient is equal to zero.
R2 coefficient of determination, SEE standard error of the estimate, n.s. not significant.