Table 2.
Sleep stage variables
| Sleep variable (min) | Children |
Teens |
||||
|---|---|---|---|---|---|---|
| Initial | Follow-up | P value | Initial | Follow-up | p value | |
| Stage 1 | 35 (15) | 35 (15) | N.S. | 33 (9) | 43 (14) | <0.001 |
| Stage 2 | 178 (62) | 229 (34) | <0.001 | 215 (41) | 254 (29) | <0.001 |
| SWS | 236 (64) | 180 (47) | <0.001 | 162 (42) | 112 (34) | <0.001 |
| REM | 103 (22) | 108 (22) | N.S. | 96 (20) | 101 (22) | N.S. |
| WASO | 31 (30) | 25 (30) | N.S. | 19 (18) | 17 (18) | N.S. |
| Sleep latency | 12 (10) | 14 (13) | N.S. | 8 (5) | 9 (6) | N.S. |
| Total sleep time | 552 (33) | 552 (30) | N.S. | 506 (4) | 511 (19) | N.S. |
| Total recording time | 600 (15) | 599 (4) | N.S | 543 (10) | 540 (7) | N.S. |
Values are given as means (SDs) in minutes for stage 1, stage 2, slow-wave sleep (SWS) and REM sleep. WASO, Minutes of waking after sleep onset, measured from first occurrence of 1.5 min of stage 1 or stage 2 to final awakening; Sleep latency, time in minutes to the first 1.5 consecutive minutes of stage 1 or first stage 2; REM sleep latency, time (in minutes) to the first REM sleep episode after sleep onset; Total sleep time, total time in minutes spent in NREM and REM sleep; Total recording time, time from lights off to lights on. Statistical significance was assessed using a paired t test (p < 0.05).