Literature-based values of control subjects in sleep medicine

Summary Question of the Study To establish literature-based values of control subjects in sleep medicine. These data should give a range for the interpretation of polysomnographic results. Patients and methods We systematically collected and pooled data of control subjects in different sleep studies. We calculated the weighted arithmetical mean of these data, i. e. the mean of the means of multiple studies, with consideration being given to the number of the individual values concerned. Since the data in the literature were not presented uniformly, we were not able to establish standard deviations. Reported sleep stages were accepted only when the Rechtschaffen and Kales classification was applied. Arousals were accepted only if established in accordance with the criteria of the American Academy of Sleep Medicine. Whenever possible we calculated data broken down for age groups. Results Usable data were obtained from studies of between 10 and 1023 control subjects. The age range extended from infancy to 85 years. Data on sleep stages, sleep latencies, arousals, oxygen saturation, partial pressure of carbon dioxide, apneas and hypopneas were processed. Sleep latency and proportion of sleep stages are influenced by the first-night effect. Conclusions The data reflect the current status. When more control data are published the tables will have to be updated.