Table 2.
Number (%) of subjects in each irregular bedtime frequency group with an average daily sleep time <7 h/day, 7–8 h/day, or >8 h/day
| ADST* | Irregular bedtime frequency+ | Total | ||
| Low | Intermediate | High | ||
| <7 h/day | 14 (8.8) | 26 (16.3) | 35 (21.9) | 75 (46.9) |
| 7–8 h/day | 17 (10.6) | 24 (15.0) | 10 (6.3) | 51 (31.9) |
| >8 h/day | 12 (7.5) | 12 (7.5) | 10 (6.3) | 34 (21.3) |
| Total | 43 (26.9) | 62 (38.8) | 55 (34.4) | 160 (100) |
ADST, average daily sleep time
+ An irregular bedtime event was defined as a shift from the usual bedtime of >1 h. This occurred <1 night/week for the low-frequency group, 1–3 nights/week for the intermediate-frequency group, and >3 nights/week for the high-frequency group.
*Chi-Square analysis indicated that average daily sleep time differed significantly across the irregular bedtime frequency groups (χ2 = 11.68, p = 0.022); as supported by a significant Spearman correlation (r = -0.22, p = 0.05).