| Variable (mean (SD)) | Primary care (n = 224) | Secondary care (n = 84) | 95% CI for difference | p Value |
| Age (years) | 53.9 (11.5) | 52.3 (11.4) | −1.3 to 4.5 | 0.29 |
| % female | 16% | 18% | – | 0.68 |
| BMI (kg/m2) | 35.7 (7.4) | 34.6 (7.0) | −1.0 to 3.2 | 0.29 |
| Epworth score | 11.4 (6.4) | 13.0 (6.4) | −3.4 to 0.7 | 0.09 |
| Daytime systolic BP | 142 (22) | 137 (20) | −1.1 to 10.9 | 0.10 |
| Daytime diastolic BP | 83 (11) | 78 (11) | 1.1 to 7.4 | 0.01 |
| Respiratory disturbance index | 36.2 (273) | 37.0 (29.9) | −7.9 to 6.2 | 0.82 |
| % with SAHS* | 86% | 80% | – | 0.13 |
*Defined as excessive daytime sleepiness and overnight RDI of at least 10 events per hour.