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.

From: Pulse oximetry values from 33,080 participants in the Apple Heart & Movement Study

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]

  1. 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.
  2. R2 coefficient of determination, SEE standard error of the estimate.