Nightly variability of sleep-disordered breathing measured over 3 nights.
OBJECTIVE
To examine the nightly variability of sleep-disordered breathing (SDB) as measured by the apnea-hypopnea index (AHI).


METHODS
Retrospective comparison of 3 sequential nights of testing performed in the home in 1091 patients who were referred for diagnostic testing of SDB.


RESULTS
The Pearson and Intraclass correlation coefficients ranged between 0.88 and 0.90 for each pair of nights. Based on night 1, approximately 90% of patients were classified consistently with "AHI-high" (the highest AHI measured across the 3 nights) using an AHI threshold of 5. However, 10% were misclassified on night 1 relative to the highest AHI level.


CONCLUSIONS
These findings suggest that (1) 1 night of diagnostic testing for SDB is not sufficient to diagnosis SDB in approximately 1 of every 10 cases, and (2) there is little, if any, significant nightly change in SDB in the home environment.


METHODS
D.
Stepnowsky
Carl J
CJ
Health Services Research & Development Service, Veterans Affairs San Diego Healthcare System, California 92161, USA. cstepnowsky@ucsd.edu
Orr
William C
WC
Davidson
Terence M
TM
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D017286:Polysomnography; D012189:Retrospective Studies; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000503:physiopathology*; D013997:Time Factors