Table 2. Responses to selected questions from the Sleep & Health Questionnaire.
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| n = 819 (Male = 207) | Mild | Moderate | Severe |
|---|---|---|---|
| Impaired performance ability | 41.5% | 8.5% | 8.7% |
| Sleepiness interfered with daily tasks | 10.2% | 3.4% | 3.8% |
| Impaired energy level | 39.2% | 8.0% | 9.4% |
| Daytime sleepiness | 41.1% | 8.5% | 22.8% |
| Snoring intensity (past month) | 33.0% | 8.2% | 5.1% |
| Snoring frequency (past month) | 24.6% | 6.7% | 19.3% |
| Frequent awakenings | 38.3% | 8.6% | 20.7% |
| Difficulty falling asleep | 48.4% | 7.8% | 9.9% |
| Observed awakenings | 6.6% | 0.7% | 0.8% |
| Observed choking | 2.8% | 1.1% | 0.7% |
| Observed apnea | 1.7% | 0.4% | 0.6% |
The responses to the questionnaire utilized either a 5-point frequency scale ("never", "rarely", "sometimes", "frequently" and "almost always"); or by the use of a 6—point Likert scale which graded the severity of the symptoms. The responses were categorized into mild, moderate and severe as follows for the purpose of data analysis18,29,30:
6-point Likert scale: 1–2 points (not affected); 3–4 points (mild); 5 points (moderate); 6 points (severe)
5-point frequency scale: never (not affected); rarely or < once/week(mild); sometimes or 1–2/week (mild); frequently or 3–4/week(moderate); almost always or 5–7/week (severe)
Responses to snoring intensity:
0 (not affected); 1–2 points (mild); 3 points (moderate); 4 points (severe)