Table 2. Baseline Characteristics of the Study Groupsa.
| No. (%) | ||
|---|---|---|
| CPAP (n = 2097) | No CPAP (n = 2089) | |
| Age, mean (SD), y | 61.1 (8.62) | 61.4 (8.77) |
| Sex | ||
| Male | 1720 (82.0) | 1717 (82.2) |
| Female | 377 (18.0) | 372 (17.8) |
| BMI, median (IQR) | 28.4 (25.9-31.2) | 28.4 (26.0-31.1) |
| Lifestyle factors | ||
| Smoking status | ||
| Never | 781 (37.3) | 811 (38.9) |
| Former | 774 (37.0) | 773 (37.1) |
| Current | 539 (25.7) | 502 (24.1) |
| Current alcohol consumption | 513 (26.1) | 497 (25.6) |
| Obstructive sleep apnea measures | ||
| Apnea-hypopnea index, median (IQR)b | 27.0 (18.0-41.0) | 27.0 (18.0-42.0) |
| Oxygen desaturation index, median (IQR)c | 24.0 (16.0-37.0) | 24.0 (16.0-38.0) |
| Mean Sao2, mean (SD) | 92.9 (5.45) | 92.9 (4.81) |
| Minimum Sao2, mean (SD) | 78.8 (6.84) | 78.6 (8.01) |
| Proportion of time with Sao2 <90%, median (IQR), % | 7.39 (2.19-19.3) | 6.76 (2.20-19.2) |
| Epworth Sleepiness Scale score, median (IQR)d | 6.00 (4.00-9.00) | 6.00 (4.00-9.00) |
| Medical historye | ||
| Hypertension | 1491 (71.2) | 1475 (70.7) |
| Any transient ischemic attack | 617 (29.5) | 626 (30.0) |
| Diabetes mellitus | 611 (29.2) | 575 (27.6) |
| Medicationf | ||
| Antihypertensive drugs | 1484 (70.9) | 1501 (71.9) |
| Antiplatelet and antithrombotic drugs | 1297 (62.0) | 1287 (61.7) |
| Lipid-lowering drug | 1118 (53.4) | 1141 (54.7) |
| Antidiabetics oral medication | 443 (21.1) | 431 (20.6) |
| Insulin | 130 (6.20) | 132 (6.32) |
Abbreviations: CPAP, continuous positive airway pressure; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); Sao2, arterial oxygen saturation.
See eTable 2 in Supplement for additional trial characteristics and to eFigure 2 in Supplement for the risk of bias assessment.
Apnea-hypopnea index (apnea was defined as an absence of airflow lasting ≥10 seconds). Hypopnea was defined as a reduction in airflow lasting ≥10 seconds, associated with oxygen desaturation. The apnea-hypopnea index was defined as the number of episodes of apnea and hypopnea per hour of recording.
Oxygen desaturation index: mean number of desaturation episodes occurring per hour, where desaturation episodes are defined as a decrease in the mean oxygen saturation of ≥4% (over the last 120 seconds) that lasts for at least 10 seconds.
Epworth Sleepiness Scale: questionnaire routinely used to assess daytime sleepiness. Total score can range from 0 to 24. A score higher than 10 is associated with sleepiness.
Medical history data were obtained from the patients by evaluating the information in patient report, performing diagnostic tests, and specific forms and self-administered questionaries.
The categories of medications were established by the clinicians participating in the study.