Table 3.
Physiological Models of CPAP Adherence (Adjusted) among Subgroups of Participants with CAD Treated with CPAP during 24 Months of Follow-up
| Variable | Men without REM-Predominant OSA (n = 182)* |
Sleepy OSA (n = 138)* |
Long-term CPAP Users (n = 174) |
||||||
|---|---|---|---|---|---|---|---|---|---|
| β (SE) | β SD | P Value | β (SE) | β SD | P Value | β (SE) | β SD | P Value | |
| Time, mo | −0.013 (0.006) | −0.040 | 0.036 | −0.016 (0.007) | −0.050 | 0.024 | −0.004 (0.006) | −0.015 | 0.529 |
| ArTH, %Ve | 0.037 (0.011) | 0.439 | 0.001 | 0.027 (0.011) | 0.325 | 0.021 | −0.001 (0.009) | −0.024 | 0.875 |
| Loop gain | −1.617 (1.389) | −0.108 | 0.246 | −1.024 (1.473) | −0.072 | 0.489 | −0.355 (1.136) | −0.020 | 0.755 |
| Vpassive, %Ve | 0.033 (0.013) | 0.297 | 0.015 | 0.028 (0.016) | 0.258 | 0.072 | 0.009 (0.012) | 0.100 | 0.446 |
| Vcomp, %Ve | −0.006 (0.009) | −0.060 | 0.483 | −0.010 (0.011) | −0.084 | 0.268 | −0.005 (0.009) | −0.046 | 0.570 |
| Vcomp2 | −5.03 × 10−4 (1.69 × 10−4) | −0.271 | 0.003 | −4.87 × 10−4 (1.93 × 10−4) | −0.257 | 0.013 | — | — | — |
| Vcomp × Vpassive | — | — | — | — | — | — | 0.001 (5.59 × 10−4) | 0.226 | 0.061 |
| ArTH × loop gain | — | — | — | — | — | — | 0.065 (0.030) | 0.154 | 0.030 |
| Vcomp × loop gain | — | — | — | — | — | — | 0.107 (0.049) | 0.174 | 0.031 |
Definition of abbreviations: ArTH = arousal threshold; CAD = coronary artery disease; CPAP = continuous positive airway pressure; ESS = Epworth Sleepiness Scale; OSA = obstructive sleep apnea; Vcomp = pharyngeal muscle compensation (higher value represents higher compensation); Ve = eupneic ventilation; Vpassive = 1/pharyngeal collapsibility (higher value represents lower collapsibility).
The models contain four main trait effects and interaction and squared terms with a P value of <0.20. Trait values were subtracted from the mean before terms were generated and applied to the model (see Measurement of Physiological Traits in the online supplement). “β SD” describes the number of SDs of change in CPAP adherence per each SD increase in each term. This enables the comparison of effect size among physiological traits. Bold indicates P < 0.05.
Adjustments are the same as those noted in Table 2 with the following exceptions. In the subgroup of men without REM-predominant OSA, there was no adjustment for sex. In the subgroup of patients with sleepy OSA, there was no adjustment for the ESS score.