Table 4.
Baseline values and changes in polysomnographic parameters
| Baseline, mean (SD)/median (IQR) | Intra-group differences, mean (95% CI) | p Value of inter-group differences | ||||
|---|---|---|---|---|---|---|
| NIV | Control | NIV | Control | Unadjusted | Adjusted | |
| TST, hours | 5.3 (1.7) | 5.4 (1.5) | −0.15 (−1 to 0.6) | 0.1 (−0.5 to 0.7) | NS | – |
| Sleep efficiency | 77 (29) | 79 (24) | −5.4 (−15 to 4.6) | 3.5 (−5.1 to 12) | NS | – |
| % Non-REM light sleep | 67 (27) | 63 (24) | −6.2 (−15 to 2.3) | −4 (−12 to 3.7) | NS | – |
| % Non-REM deep sleep | 18 (17) | 23 (18) | 4.6 (−3.2 to 12) | 1.6 (−6.4 to 9.6) | NS | – |
| % REM sleep | 8.7 (8.9) | 13 (15) | 5.6 (−0.9 to 12) | 3.3 (−3 to 9.6) | NS | – |
| Arousal index | 25 (20) | 22 (18) | −10 (−14 to −6.2)‡ | −0.3 (−2.9 to 2.3) | 0.000 | 0.000 |
| AHI | 14 (8.9) | 15 (7.8) | −11 (−15 to −7.1)‡ | 0.1 (−2.7 to 2.8) | 0.000 | 0.000 |
| DI | 18 (27) | 19 (16) | −19 (−25 to −12)‡ | −0.4 (−4.6:3.8) | 0.000 | 0.000 |
| Mean SaO2 | 88 (8) | 87 (5) | 6 (4.3 to 7.7)‡ | 0.4 (−0.5 to 1.4) | 0.000 | 0.000 |
| %TST <90 | 82 (58) | 69 (79) | −36 (−46 to −25)‡ | −5.7 (−15 to 2) | 0.000 | 0.002 |
Median (IQR) values are shown in italic.
Bold type indicates statistical significance.
p Values of intra-group differences (2 months − baseline): ‡p<0.001.
p Values of inter-group differences unadjusted or adjusted by basic adjustment (baseline values of the variable analysed and age, gender, BMI and AHI).
AHI, apnoea–hypopnoea index; BMI, body mass index; DI, desaturation index; %TST <90, percentage of TST below 90% of oxygen saturation; NIV, non-invasive ventilation; REM, rapid eye movement; SaO2, arterial oxygen saturation; TST, total sleep time.