@article {645, title = {Methods for obtaining and analyzing unattended polysomnography data for a multicenter study. Sleep Heart Health Research Group.}, journal = {Sleep}, volume = {21}, year = {1998}, month = {1998 Nov 01}, pages = {759-67}, abstract = {

This paper reviews the data collection, processing, and analysis approaches developed to obtain comprehensive unattended polysomnographic data for the Sleep Heart Health Study, a multicenter study of the cardiovascular consequences of sleep-disordered breathing. Protocols were developed and implemented to standardize in-home data collection procedures and to perform centralized sleep scoring. Of 7027 studies performed on 6697 participants, 5534 studies were determined to be technically acceptable (failure rate 5.3\%). Quality grades varied over time, reflecting the influences of variable technician experience, and equipment aging and modifications. Eighty-seven percent of studies were judged to be of "good" quality or better, and 75\% were judged to be of sufficient quality to provide reliable sleep staging and arousal data. Poor submental EMG (electromyogram) accounted for the largest proportion of poor signal grades (9\% of studies had <2 hours artifact free EMG signal). These data suggest that with rigorous training and clear protocols for data collection and processing, good-quality multichannel polysomnography data can be obtained for a majority of unattended studies performed in a research setting. Data most susceptible to poor signal quality are sleep staging and arousal data that require clear EEG (electroencephalograph) and EMG signals.

}, keywords = {Electroencephalography, Electromyography, Feasibility Studies, Humans, Licensure, Polysomnography, Research Design, Sleep Apnea Syndromes, Teaching}, issn = {0161-8105}, author = {Redline, S and Sanders, M H and Lind, B K and Quan, S F and Iber, C and Gottlieb, D J and Bonekat, W H and Rapoport, D M and Smith, P L and Kiley, J P} } @article {1523, title = {Relation of sleepiness to respiratory disturbance index: the Sleep Heart Health Study.}, journal = {Am J Respir Crit Care Med}, volume = {159}, year = {1999}, month = {1999 Feb}, pages = {502-7}, abstract = {

Obstructive sleep apnea syndrome is a well recognized cause of excessive sleepiness; however, the relation of sleepiness to mild sleep-disordered breathing (SDB), which affects as much as half the adult population, is uncertain. In order to explore this relation, we conducted a cross-sectional cohort study of community-dwelling adults participating in the Sleep Heart Health Study, a longitudinal study of the cardiovascular consequences of SDB. The study sample comprises 886 men and 938 women, with a mean age of 65 (SD 11) yr. Sleepiness was quantified using the Epworth Sleepiness Scale (ESS). Sleep-disordered breathing was quantified by the respiratory disturbance index (RDI), defined as the number of apneas plus hypopneas per hour of sleep, measured during in-home polysomnography. When RDI was categorized into four groups (< 5, 5 to < 15, 15 to < 30, >/= 30), a significantly progressive increase in mean ESS score was seen across all four levels of SDB, from 7.2 (4.3) in subjects with RDI < 5 to 9.3 (4.9) in subjects with RDI >/= 30 (p < 0.001). There was no significant modification of this effect by age, sex, body mass index, or evidence of chronic restriction of sleep time or periodic limb movement disorder. The percentage of subjects with excessive sleepiness, defined as an ESS score >/= 11, increased from 21\% in subjects with RDI < 5 to 35\% in those with RDI >/= 30 (p < 0. 001). We conclude that SDB is associated with excess sleepiness in community-dwelling, middle-aged and older adults, not limited to those with clinically apparent sleep apnea.

}, keywords = {Aged, Cardiovascular Diseases, Cross-Sectional Studies, Disorders of Excessive Somnolence, Female, Humans, Male, Middle Aged, Polysomnography, Respiration, Retrospective Studies, Severity of Illness Index, Sleep Apnea Syndromes, Surveys and Questionnaires}, issn = {1073-449X}, doi = {10.1164/ajrccm.159.2.9804051}, author = {Gottlieb, D J and Whitney, C W and Bonekat, W H and Iber, C and James, G D and Lebowitz, M and Nieto, F J and Rosenberg, C E} } @article {609, title = {Effects of varying approaches for identifying respiratory disturbances on sleep apnea assessment.}, journal = {Am J Respir Crit Care Med}, volume = {161}, year = {2000}, month = {2000 Feb}, pages = {369-74}, abstract = {

Varying approaches to measuring the respiratory disturbance index (RDI) may lead to discrepant estimates of the severity of sleep-disordered breathing (SDB). In this study, we assessed the impact of varying the use of corroborative data (presence and degree of desaturation and/or arousal) to identify hypopneas and apneas. The relationships among 10 RDIs defined by various definitions of apneas and hypopneas were assessed in 5,046 participants in the Sleep Heart Health Study (SHHS) who underwent overnight unattended 12-channel polysomnography (PSG). The magnitude of the median RDI varied 10-fold (i.e., 29.3 when the RDI was based on events identified on the basis of flow or volume amplitude criteria alone to 2.0 for an RDI that required an associated 5\% desaturation with events). The correlation between RDIs based on different definitions ranged from 0.99 to 0.68. The highest correlations were among RDIs that required apneas and hypopneas to be associated with some level of desaturation. Lower correlations were observed between RDIs that required desaturation as compared with RDIs defined on the basis of amplitude criteria alone or associated arousal. These data suggest that different approaches for measuring the RDI may contribute to substantial variability in identification and classification of the disorder.

}, keywords = {Adult, Aged, Aged, 80 and over, Arousal, Diagnosis, Differential, Female, Humans, Lung Volume Measurements, Male, Middle Aged, Observer Variation, Oxygen, Oxyhemoglobins, Polysomnography, Risk Factors, Sleep Apnea Syndromes}, issn = {1073-449X}, doi = {10.1164/ajrccm.161.2.9904031}, author = {Redline, S and Kapur, V K and Sanders, M H and Quan, S F and Gottlieb, D J and Rapoport, D M and Bonekat, W H and Smith, P L and Kiley, J P and Iber, C} }