Table 1.

Tabulated comparison of reference SaO₂ linear model coefficients (top row of coefficients; adapted from ref. ³) with results obtained from equivalent fits to daytime mean SpO₂ (bottom row of coefficients) using only low-altitude subjects (estimated home altitude < 155m) from our data set.

Univariate regression results for blood oxygen saturation (low-altitude subjects only)
Model	R2	SEE	Constant	Age (years)
Reference univariate SaO2 (Crapo et al.3)	0.32	0.85	97.66	−0.0296
Daytime SpO2 (low-alt. subjects)	0.12	1.14	97.65 (97.57, 97.74)) [p < 1.0e−10]	−0.0322 (−0.0341, −0.0303)) [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.