Disruption of sleep by one night of in-home polysomnographic recording: a longitudinal actigraphy study of patients with chronic musculoskeletal pain and pain-free controls

Patients with chronic pain frequently have comorbid sleep disturbances. Since improvement of sleep may alleviate both sleep problems and to some extent pain, sleep studies in this group becomes relevant. Polysomnography (PSG) is considered the gold standard for characterizing sleep; however, it is resource-demanding and may itself disrupt sleep due to the use of inconvenient equipment in unfamiliar sleep environments. To circumvent disruptive first night effect that may occur, sleep protocols may prescribe several nights of PSG to facilitate adaptation despite the equipment may still influence sleep on all nights. Moreover, the disruptive effects of polysomnography may vary between patient groups and healthy persons, yet have not previously been studied in patients with chronic pain. The present study aimed to assess whether sleep disruption during one night of in-home PSG was more severe in patients with chronic musculoskeletal pain compared to pain-free controls. Sleep was assessed by self-reported sleep quality and actigraphy measured sleep onset latency, sleep duration, wake after sleep onset and sleep efficiency during one night of in-home PSG and the following six nights in 56 patients and 53 pain-free participants. Additionally, sleep schedule was assessed by sleep onset time, wake up time and time in bed. The repeated sleep measures were analysed with mixed model regressions, comparing mean score changes between and within groups. A disruptive effect of PSG was evident for self-reported sleep quality and actigraphy measured sleep onset latency in both groups. These effects were however not significantly different between the groups, indicating comparable sensitivity to a single night of PSG between pain patients and pain-free controls. These findings suggest that a singlenight in-home PSG protocol may be considered for case–control studies of patients with chronic pain.