Models for moderate-to-severe sleep apnoea (AHI ≥15), CAI ≥5 and central sleep apnoea using different predictors
| Predictors | Unit of analysis | OR (95% CI) | P value | OR (95% CI) | P value |
| Moderate-to-severe sleep apnoea (AHI ≥15) with 6 predictors | Sleep apnoea (AHI ≥5) with 6 predictors | ||||
| STOP-Bang score | 1 | 1.70 (1.34 to 2.16) | <0.0001 | 1.48 (1.19 to 1.84) | 0.0004 |
| Daytime SpO2 | 1% decrease | 1.33 (1.12 to 1.58) | 0.002 | 1.30 (1.08 to 1.56) | 0.006 |
| MME | 10 mg | 1.01 (0.99 to 1.02) | 0.352 | 1.02 (0.999 to 1.034) | 0.067 |
| Epworth Sleepiness Scale* | 11–24 vs 0–10 | 1.19 (0.56 to 2.51) | 0.650 | 0.93 (0.46 to 1.89) | 0.841 |
| Mallampati score* | ≥3 vs <3 | 1.23 (0.59 to 2.57) | 0.580 | 1.16 (0.59 to 2.27) | 0.666 |
| Thyromental distance | 1 cm | 1.08 (0.89 to 1.30) | 0.449 | 1.05 (0.88 to 1.25) | 0.609 |
| Model for CAI ≥5 with 3 predictors (n=33 participants) | Model for central sleep apnoea (n=24 participants) | ||||
| Daytime SpO2 | 1% decrease | 1.45 (1.19 to 1.78) | 0.0003 | 1.47 (1.17 to 1.84) | 0.001 |
| MME | 10 mg | 1.03 (1.02 to 1.05) | <0.0001 | 1.04 (1.02 to 1.06) | <0.0001 |
| STOP-Bang score | 1 | 1.10 (0.85 to 1.42) | 0.4563 | ||
An outlier value (74%) for SpO2 was removed from the analysis.
*Mallampati score and Epworth Sleepiness Scale expressed as dichotomous variables. Participants were stratified to have central sleep apnoea if greater than or equal to 50% of events were central in nature.15
AHI, Apnoea-Hypopnoea Index; CAI, Central Apnoea Index;MME, morphine milligram equivalents; SpO2, oxyhaemoglobin saturation; STOP-Bang, a screening tool for sleep apnoea (Snoring, Tiredness, Observed apnoea, high blood Pressure, Body mass index, age, neck circumference and male gender).