Hyperbaric oxygen, Chronic insomnia, High altitude, Arctic medicine. Tropical medicine, RC955-962, Infectious and parasitic diseases, RC109-216

Background: Hyperbaric oxygen (HBO) has been proposed to be effective for treating chronic insomnia at high altitudes. Methods: Patients suffering from chronic insomnia at high altitude were randomly assigned at a 1:1 ratio to either the hyperbaric oxygen (HBO) treatment group or the control group for a 10-day procedure. The primary outcome was insomnia status, which was assessed via the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI). The secondary outcomes included stratified comparisons of changes in the PSQI score and ISI score, Fatigue Severity Scale (FSS) score and Hospital Anxiety and Depression Scale (HADS) score. Analyses were performed for multiple comparisons for the primary outcomes at 2-sided 0.05 significance levels with Bonferroni corrections. Results: A total of 80 patients were randomized in this study, and the median age was 25.0 years (IQR, 21.25–29.75). For the primary outcome of sleep quality, the PSQI score after treatment was significantly lower in the HBO group than in the control group (4.6 ± 3.15 vs. 9.1 ± 4.02; adjusted mean difference [aMD] −3.96 [-5.26 to −2.66], p