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Table 2 Results of sleep parameters by the NSCAN and PSG

From: Validity of an under-mattress sensor for objective sleep measurement in critically ill patients: a prospective observational study

 MedianInterquartile range
PSG nighttime (21:00–05:59)
 TST (min)456.0353.0–517.5
 SE (%)84.465.4–95.8
 WK (%)15.64.2–34.6
 N1 (%)22.214.4–41.4
 N2 (%)20.519.3–53.5
 N3 (%)0.40.0–4.4
 REM (%)0.10.0–1.8
 Arousal index (arousals/h)14.18.0–20.3
 Frequency of sleep stage shift (/h)8.92.9–11.5
PSG daytime (06:00–20:59)
 TST (min)305.0186.2–542.5
 SE (%)33.921.9–60.3
 WK (%)66.139.7–78.1
 N1 (%)22.013.1–30.0
 N2 (%)8.24.1–19.6
 N3 (%)0.00.0–0.7
 REM (%)0.00.0–0.6
NSCAN total recorded epochs (WK+Sleep+Out-of-bed)30,212 
 NSCAN battery disconnection1468 
NSCAN nighttime
 TST (min)500.0444.5–525.5
 SE (%)96.382.3–98.6
NSCAN daytime
 TST (min)710.0517.0–750.5
 SE (%)78.965.8–84.3
RCSQ (average of 5 questions)68.026.3–83.5
 Sleep depth62.033.0–86.5
 Sleep latency65.036.5–81.5
 Frequency of awakenings60.017.0–81.5
 Sleep latency after awakenings80.021.0–90.0
 Sleep quality68.020.0–91.0
  1. The “frequencies of sleep stage shift” indicates the transition number per hour among WK, REM, and NREM
  2. Abbreviations: Arousal index arousal numbers per hour, N1 sleep stage N1, N2 sleep stage N2, N3, sleep stage N3, NREM non-rapid eye movement sleep (i.e., N1 + N2 + N3), NSCAN Nemuri SCAN, PSG polysomnography, RCSQ Richards–Campbell Sleep Questionnaire, REM rapid eye movement, TST total sleep time (N1 + N2 + N3 + REM), SE sleep efficiency (TST/540 for nighttime; TST/900 for daytime), WK wake