Table 1.
Demographic information and sleep characteristics.
| Total sample (N = 10,299) |
Fragmented sleepers (N = 2867) |
Delayed onset sleepers (N = 3220) |
Perceived poor sleepers (N = 1257) |
Good sleepers (N = 2,946) |
H / X2 | p | Post-hoc analyses* | |
|---|---|---|---|---|---|---|---|---|
| Sex (% women) | 68.9% | 80.5% | 66.2% | 67.2% | 61.3% | 271 | < 0.001 | a,b,c,e,f |
| Age (years) median (IQR) | 32 (24) | 34 (28) | 28 (21) | 28 (19) | 36 (24) | 302 | < 0.001 | a,b,e,f |
| Years of education median (IQR) | 15 (1) | 14 (3) | 15 (1) | 15 (2) | 15 (2) | 245 | < 0.001 | a,b,c,d,e |
| Daytime function (PSQI) median (IQR) | 1 (1) | 1 (1) | 1 (0) | 1 (1) | 1 (1) | 894 | < 0.001 | a,b,c,d,e,f |
| Sleep | ||||||||
| Total PSQI score median (IQR) | 5 (4) | 8 (5) | 7 (3) | 4 (1) | 3 (2) | 6430 | < 0.001 | a,b,c,d,e,f |
| Duration (hours) median (IQR) | 7 (2) | 6.75 (1.5) | 6.5 (1) | 7.5 (1) | 7.5 (1) | 1755 | < 0.001 | b,c,d,e,f |
| Efficiency (PSQI) median (IQR) | 0 (1) | 1 (2) | 1 (1) | 0 (0) | 0 (0) | 2290 | < 0.001 | a,b,c,d,e,f |
| Disturbances (PSQI) median (IQR) | 1 (1) | 2 (0) | 1 (0) | 1 (0) | 1 (0) | 9404 | < 0.001 | a,b,c,d,e,f |
| Onset latency (minutes) median (IQR) | 20 (20) | 30 (45) | 30 (40) | 15 (20) | 10 (10) | 3301 | < 0.001 | a,b,c,d,e,f |
| Subjective quality (PSQI) median (IQR) | 1 (1) | 1 (1) | 1 (1) | 1 (0) | 0 (1) | 3707 | < 0.001 | a,b,c,d,e,f |
| Bed time (24 h clock) median (IQR) | 23 (1) | 23 (1) | 23 (1) | 23 (1) | 23 (1) | 47.7 | < 0.001 | a,c,d,e,f |
| Get-up time (24 h clock) median (IQR) | 7 (1) | 7 (1) | 7 (1) | 7 (1) | 7 (1) | 22.2 | < 0.001 | a,c,f |
| Sleep medication (PSQI) median (IQR) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 508 | <0 .001 | a,b,c,d,e,f |
IQR: inter-quartile range; PSQI: score (0–3) from Pittsburg Sleep Quality Inventory; H = Kruskal–Wallis test statistic; X2 = Pearson’s chi-square test statistic; *a: fragmented sleepers differ from delayed onset sleepers; b: fragmented sleepers differ from perceived poor sleepers; c: fragmented sleepers differ from good sleepers; d: delayed onset sleepers differ from perceived poor sleepers; e: delayed onset sleepers differ from good sleepers; f: perceived poor sleepers differ from good sleepers.