Table 1.
Participants' characteristics and OSA group CPAP treatment information.
| OSA before CPAP (A) (n = 37) |
OSA after CPAP (B) (n = 37) |
Controls (C) (n = 27) |
A versus B t (df) |
B versus C t (df) |
|
|---|---|---|---|---|---|
| Age (years) | 57.9 (9.5)a | 56.7 (10.5) | 0.48 (62) | ||
| Sex (F : M) | 15 : 22 | 19 : 8 | |||
| Education (years) | 15.1 (3.6) | 15.7 (3.2) | 0.61 (62) | ||
| Body mass index (BMI) | 33.5 (7.4) | 25.5 (5.0) | 4.83 (62)*** | ||
| Time since diagnosis of OSA (months) | 25.6 (21.1) | ||||
| Duration of CPAP treatment (months) | 17.8 (11.4) | ||||
| Usage of CPAP per week (hours) | 51.4 (6.7) | ||||
| CPAP complianceb | 96.1 (5.6) | ||||
| Respiratory disturbance index (RDI) | 42.2 (24.9) | 1.7 (1.5) | 4.0 (3.4) | 9.52 (32)*** | 3.25 (62)** |
| Minimum oxygen saturation (min SpO2) | 80.2 (9.8) | 90.3 (3.6) | 88.6 (3.3) | 5.61 (27)*** | 1.90 (60) |
| Mean oxygen saturation (mean SpO2) | 93.7 (3.5) | 95.7 (1.6) | 95.7 (0.9) | 3.17 (29)** | 0.10 (62) |
| Epworth Sleepiness Scale (ESS) | 14.4 (5.2) | 8.3 (4.5) | 6.6 (4.7) | 7.52 (36)*** | 1.48 (62) |
| Pittsburg Sleep Quality Index—global score | 8.5 (3.3) | 4.4 (2.4) | 4.6 (2.8) | 5.85 (27)*** | 0.20 (62) |
CPAP: continuous positive airway pressure.
aMean (SD).
bCPAP compliance is defined as percentage of days with usage >4 hours in the last 3 months. Compliance was determined objectively by downloading data from the built-in smart card of the CPAP machines for 73% of the participants. Self-report of usage was used for the rest of the participants whose machines were not equipped with a smart card.
**P < .01, ***P < .001.