| Characteristic | Females# | Males¶ | Total | ||
| AHI <15 | AHI ≥15 or CPAP | AHI <15 | AHI ≥15 or CPAP | ||
| Sleep studies n | 1472 | 211 | 1617 | 395 | 3695 |
| Age yrs | |||||
| Minimum | 32 | 35 | 33 | 34 | 32 |
| 1st quartile | 48 | 52 | 49 | 53 | 49 |
| Median | 54 | 57 | 55 | 60 | 55 |
| 3rd quartile | 61 | 62 | 62 | 65 | 62 |
| Maximum | 81 | 77 | 80 | 78 | 81 |
| Body mass index kg·m−2 | 31±7 | 41±10 | 29±5 | 35±7 | 31±7 |
| Epworth Sleepiness Score | 8±4 | 9±4 | 9±4 | 10±4 | 9±4 |
| Epworth Sleepiness Score ≥10 | 525 (36) | 93 (44) | 683 (42) | 211 (53) | 1512 (41) |
| MSLT min+ | 11±5 | 10±6 | 9±5 | 9±5 | 10±5 |
| MSLT ≤5 min+ | 109 (15) | 19 (24) | 181 (22) | 53 (27) | 362 (20) |
| Habitual sleep time h | 7±1 | 7±1 | 7±1 | 7±1 | 7±1 |
| Naps per week h | 1±2 | 2±2 | 2±2 | 2±3 | 2±2 |
| Depression§ | 450 (31) | 102 (48) | 273 (17) | 85 (22) | 910 (25) |
| Trait Anxiety Scale | 34±8 | 35±9 | 32±8 | 32±8 | 33±9 |
| Comorbid conditions | 74 (5) | 15 (8) | 162 (10) | 84 (21) | 335 (9) |
| Stroke | 25 (2) | 5 (2) | 14 (1) | 12 (3) | 56 (2) |
| Heart failure | 10 (1) | 2 (1) | 8 (0.5) | 8 (2) | 28 (1) |
| Cardiovascular diseaseƒ | 44 (3) | 10 (5) | 150 (9) | 74 (19) | 278 (8) |
| Arthritis## | 380 (35) | 104 (57) | 230 (20) | 101 (32) | 815 (30) |
| Chronic joint/back pain## | 253 (23) | 61 (33) | 166 (14) | 61 (19) | 541 (20) |
| Current smoker | 175 (12) | 21 (10) | 190 (12) | 42 (11) | 428 (12) |
| Physical activity per week h | 2±3 | 2±2 | 3±3 | 2±2 | 2±3 |
| Hypnotic medication use | 125 (8) | 18 (8) | 62 (4) | 24 (6) | 229 (6) |
| Alcoholic drinks per week | 1 (0–36) | 0 (0–17) | 3 (0–42) | 2 (0–32) | 2 (0–42) |
| Caffeinated drinks per day | 2±2 | 2±2 | 3±2 | 3±3 | 3±2 |
| CPAP use | NA | 87 (41) | NA | 144 (36) | 231 (6) |
Data are presented as mean±sd, n (%) or median (range), unless otherwise stated. Data are reported on the number of sleep studies, with most subjects contributing to multiple studies. AHI: apnoea/hypopnoea index; CPAP: continuous positive airway pressure; MSLT: multiple sleep latency test; NA: not available. #: n=1,683; ¶: n=2,012; +: sample size n=1,846; §: using antidepressant medication and/or Zung depression scale ≥50; ƒ: heart attack, coronary artery disease or cardiovascular surgical procedure; ##: these questions were added after the study began and are available in a subset.