Baseline characteristics from patients
| 2019 | 2020 | |
| Total | 620 | 567 |
| Age (years) | 53.4±13.6 | 53.4±13.3 |
| Gender | ||
| Female | 206 (33.2%) | 185 (32.6%) |
| Male | 414 (66.8%) | 380 (67.0%) |
| Ethnicity | ||
| White | 476 (76.8%) | 383 (67.5%) |
| Asian | 18 (2.9%) | 12 (2.1%) |
| Black | 10 (1.6%) | 10 (1.8%) |
| Other | 7 (1.2%) | 5 (0.9%) |
| Unknown | 109 (17.6%) | 157 (27.7%) |
| BMI (kg/m2) | 34.9 (30.6, 41.0) | 34.8 (29.5, 40.4) |
| ESS | 11.2±5.5 | 11.8±5.2 |
| ODI (/hour) | 23.0 (14.1, 43.0) | 21.5 (13.0, 41.8) |
| AHI (/hour) | 25.5 (15.0, 40.4) | 25.7 (14.5, 46.8) |
Data are expressed as mean±SD, median (first quartile, third quartile) or number (percentage), as appropriate.
AHI, Apnoea–Hypopnoea Index; BMI, body mass index; ESS, Epworth Sleepiness score; ODI, Oxygen Desaturation Index ≥4%.