Mean value for each night (SD), mean within-patient difference, SD of with-patient differences and 95% limits of agreement across three pairs of nights for each of the three values tested
| N | Means (SD) | Mean difference | SD of differences | Bland–Altman 95% limits of agreement | |
|---|---|---|---|---|---|
| Basal oxygen SpO2 (%) | |||||
| Night 1–night 2 | 179 | Night 1= 96.1 (2.79) Night 2=96.2 (2.47) | 0.076 | 2.41 | −4.6 to 4.8 |
| Night 1–night 3 | 147 | Night 1=96.4 (2.3) Night 3=96.7 (2.02) | 0.28 | 1.78 | −3.2 to 3.7 |
| Night 2–night 3 | 150 | Night 2=96.4 (2.28) Night 3=96.6 (2.01) | 0.15 | 1.45 | −2.7 to 3.0 |
| Adjusted index | |||||
| Night 1–night 2 | 178* | Night 1=5.44 (7.30) Night 2=6.21 (8.76) | −0.76 | 4.91 | −8.8 to 10.4 |
| Night 1–night 3 | 147 | Night 1=5.21 (7.58) Night 3=5.04 (8.00) | 0.17 | 4.80 | −9.6 to 9.3 |
| Night 2–night 3* | 149* | Night 2=5.92 (8.79) Night 3=5.29 (8.00) | 0.63 | 4.45 | −9.4 to 8.1 |
| Time with SpO2<90% (as % of time recorded) | |||||
| Night 1–night 2 | 179 | Night 1= 4.92 (11.9) Night 2=4.75 (10.9) | 0.17 | 10.6 | −20.8 to 20.6 |
| Night 1–night 3 | 147 | Night 1=4.11 (10.7) Night 3=3.04 (8.77) | 1.07 | 9.59 | −19.8 to 17.7 |
| Night 2–night 3 | 150 | Night 2=3.66 (8.86) Night 3=3.12 (8.76) | 0.53 | 6.56 | −13.4 to 12.3 |
*One patient had no data of desaturations per hour recorded on night 2.