Table 2.
Summary of Unadjusted Univariate Cox Regression Analyses for the Primary Composite End Point of the Sleep Apnea Cardioascular Endpoints (SAVE) Study
| Variable | Hazard Ratioa | 95% CIa | P Value |
|---|---|---|---|
| Apnea-hypopnea index, events/h | 0.99 | 0.98-1.00 | .066 |
| Patterns of nocturnal hypoxemia (custom MATLAB [MathWorks] algorithm) | |||
| Oxygen desaturation index, events/h | 0.99 | 0.98-1.00 | .072 |
| T<90%, min (log transformed) | 1.00 | 0.94-1.07 | .988 |
| Mean Spo2, % | 0.99 | 0.94-1.04 | .652 |
| Baseline Spo2, % | 0.96 | 0.91-1.01 | .141 |
| Desaturation Spo2, % (log transformed) | 0.93 | 0.81-1.06 | .262 |
| Desaturation duration, s | 1.01 | 1.00-1.02 | .039 |
| Desaturation/resaturation time ratio | 0.93 | 0.80-1.08 | .329 |
| Desaturation average Spo2 reduction, % | 0.94 | 0.86-1.03 | .166 |
| Desaturation nadir, % | 1.00 | 0.97-1.04 | .886 |
| Pulse mean, beats/min | 0.99 | 0.99-1.01 | .774 |
| Pulse SD, beats/min | 1.00 | 0.95-1.05 | .987 |
a
From crude (univariate) Cox regressions for the primary composite end point of SAVE, with the use of individual measures as univariate continuous covariates. Regression analyses were stratified according to CPAP treatment allocation, with no other adjustments. Spo2 = oxygen saturation.