Age- and sex-specific prevalence rates of the apnoea/hypopnoea index (AHI) based on polysomnographic (PSG) results for a sample of 352 males and 250 females from Wisconsin, USA
| Age yrs | AHI | ||
| ≥5 | ≥10 | ≥15 | |
| Males | |||
| 30–39 | 17.0 (9.6–25) | 12.0 (5.4–19) | 6.2 (1.9–10) |
| 40–49 | 25.0 (18–32) | 18.0 (11–24) | 11.0 (6.7–16) |
| 50–60 | 31.0 (21–40) | 14.0 (7.5–20) | 9.1 (5.1–13) |
| Females | |||
| 30–39 | 6.5 (1.4–11) | 4.9 (0.6–9.8) | 4.4 (1.1–7.3) |
| 40–49 | 8.7 (4.2–13) | 4.9 (1.7–8.1) | 3.7 (1.0–6.5) |
| 50–60 | 16.0 (5.2–26) | 5.9 (0.0–12.0) | 4.0 (0.0–10) |
Data are presented as % (95% confidence interval). Data were collected as follows. Overnight in-lab PSG recording was carried out in sound-attenuated, light- and temperature-controlled rooms using standard set-up and a 16-channel polygraph (Model 78d; Grass Instrument, Quincy, MA, USA). Manual scoring using conventional criteria was employed. An abnormal breathing event was defined as complete cessation of airflow for ≥10 s (apnoea) or a discernible 50% reduction in respiratory airflow accompanied by a decrease of ≥4% in arterial oxygen saturation measured by pulse oximetry. Reproduced from 3, with permission from the publisher.