Sleep classification according to AASM and Rechtschaffen & Kales: effects on sleep scoring parameters.
OBJECTIVE
To investigate differences between visual sleep scoring according to the classification developed by Rechtschaffen and Kales (R&K, 1968) and scoring based on the new guidelines of the American Academy of Sleep Medicine (AASM, 2007).


METHODS
All-night polysomnographic recordings were scored visually according to the R&K and AASM rules by experienced sleep scorers. Descriptive data analysis was used to compare the resulting sleep parameters.


METHODS
Healthy subjects and patients (38 females and 34 males) aged between 21 and 86 years.


METHODS
N/A.


RESULTS
While sleep latency and REM latency, total sleep time, and sleep efficiency were not affected by the classification standard, the time (in minutes and in percent of total sleep time) spent in sleep stage 1 (S1/N1), stage 2 (S2/N2) and slow wave sleep (S3+S4/N3) differed significantly between the R&K and the AASM classification. While light and deep sleep increased (S1 vs. N1 [+10.6 min, (+2.8%)]: P<0.01; S3+S4 vs. N3 [+9.1 min (+2.4%)]: P<0.01), stage 2 sleep decreased significantly according to AASM rules (S2 vs. N2 [-20.5 min, (-4.9%)]: P<0.01). Moreover, wake after sleep onset was significantly prolonged by approximately 4 minutes (P<0.01) according to the AASM standard. Interestingly, the effects on stage REM were age-dependent (intercept at 20 years: -7.5 min; slope: 1.6 min for 10-year age increase). No effects of sex and diagnosis were observed.


CONCLUSIONS
The study shows significant and age-dependent differences between sleep parameters derived from conventional visual sleep scorings on the basis of R&K rules and those based on the new AASM rules. Thus, new normative data have to be established for the AASM standard.
Moser
Doris
D
Department of Neurology, Medical University of Vienna, Vienna, Austria.
Anderer
Peter
P
Gruber
Georg
G
Parapatics
Silvia
S
Loretz
Erna
E
Boeck
Marion
M
Kloesch
Gerhard
G
Heller
Esther
E
Schmidt
Andrea
A
Danker-Hopfe
Heidi
H
Saletu
Bernd
B
Zeitlhofer
Josef
J
Dorffner
Georg
G
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001008:Anxiety Disorders / Q000175:diagnosis / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis / Q000503:physiopathology; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology; D017286:Polysomnography / Q000145:classification* / Q000706:statistics & numerical data; D017410:Practice Guidelines as Topic; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D015203:Reproducibility of Results; D012894:Sleep Stages / Q000502:physiology; D055815:Young Adult