Sleep latency and duration estimates among sleep disorder patients: variability as a function of sleep disorder diagnosis, sleep history, and psychological characteristics.

Insomnia patients often report greater sleep disturbance than found via polysomnography; yet the specific patient factors related to such sleep time misperceptions are poorly understood. We sought to characterize the extent to which a diverse group of patients complaining of insomnia (n=104) misperceive overnight total sleep time and sleep latency, and to identify patient factors associated with these variations.