Social Jet Lag Estimated From CPAP Adherence Data in Two Obstructive Sleep Apnea Cohorts
BackgroundSocial jet lag (SJL), the discrepancy timing between work nights and free nights, reflects schedule-related circadian misalignment. Time-stamped CPAP adherence records may provide objective, longitudinal estimates of sleep timing and could augment conventional CPAP reports by adding information on sleep regularity and weekday-weekend misalignment. ObjectivesTo quantify CPAP-derived SJL in two independent clinical cohorts, characterize its behavioral correlates and age-related patterns, and assess cross-site reproducibility. MethodsWe analyzed CPAP-derived sleep timing in patients from Rutgers-RWJ Health (RWJ, N = 1,437) and Hackensack Meridian Health (HMH, N = 1,510) with at least 31 valid nights and at least one valid work night and free night. Mid-sleep on work nights (MSW) and free nights (MSF) was estimated using circular statistics. SJL was defined as the absolute circular difference between MSF and MSW and categorized as none (<1 h), moderate (1-2 h), or severe ([≥]2 h). Sleep duration, free-night rebound, age-stratified prevalence, and cross-site differences were evaluated using nonparametric and categorical tests. ResultsSJL was right-skewed at both sites, with median values below 0.5 h at RWJ and HMH. SJL >1 h was present in 21.2% and 16.4% of patients, respectively; severe SJL occurred in 4.0% and 2.8%. Moderate and severe SJL were associated with shorter work-night sleep and greater free-night rebound, consistent with weekday restriction and weekend compensation. SJL prevalence and variability were highest in younger and middle-aged adults, particularly those aged 26-50 years, and declined markedly after age 65. Core timing phenotypes, including MSW, MSF, and free-night rebound, were highly reproducible across sites despite modest differences in absolute sleep duration and overall SJL prevalence. ConclusionsIn CPAP-treated cohorts, SJL is common but usually modest, is associated with weekday sleep restriction and free-night rebound, and declines substantially with age. These findings support the use of routinely collected CPAP data as a scalable, low-burden source of device-anchored circadian screening phenotypes. CPAP-derived SJL may augment standard adherence reports by helping identify patients who warrant further behavioral, circadian, or activity-based assessment.