The Effect of Noise-masking Earbuds (SleepBudsTM) on Reported Sleep Quality and Tension in Health Care Shift Workers: a Prospective, Single-Subject Design Study (Preprint)

BACKGROUND Shift work is associated with sleep disorders which impair alertness and increase risk of chronic physical and mental health disease. In health care workers, shift work and its associated sleep loss decreases provider wellness and can compromise patient care. Pharmacological sleep aids or substances such as alcohol are often used to improve sleep with variable effects on health and wellbeing. OBJECTIVE We tested whether use of noise-masking earbuds can improve reported sleep quality, sleepiness, and stress level in health care shift workers, and increase alertness and reaction time post-night shift. METHODS Emergency medicine resident physicians were recruited for a prospective, single-subject design study. Entrance surveys on current sleep habits were completed. For 14 days, participants completed daily surveys reporting sleep aid use, and self-rated perceived sleepiness, tension level, and last nights’ sleep quality using an 8-point Likert scale. After overnight shifts, 3-minute psychomotor vigilance tests (PVT) measuring reaction time were completed. At the end of 14 days participants were provided noise-masking earbuds and used them in addition to their baseline sleep regimens as needed for sleep for the remainder of the study period. Daily sleep surveys, post-overnight shift PVT, and earbud use data was collected for an additional 14 days. A linear mixed effects regression model was used to assess changes in the pre- and post-intervention outcomes with participants serving as their own controls. RESULTS 36 residents were recruited, of these, 26 participants who completed daily sleep surveys and used earbuds at least once during the study period were included in final analysis. The median number of days of earbud use was 5 days (IQR [2, 9]) of the available 14 days. On days when residents reported earbud use, previous nights’ sleep quality increased by 0.5 points (P<.0001, 95% CI 0.23-0.80), daily sleepiness decreased by 0.6 points (P<.0001, 95% CI -0.90 to -0.34), and total daily tension decreased by 0.6 points (P<.0001, 95% CI -0.81 to -0.32). These effects were more pronounced in participants who reported worse than average pre-intervention sleep scores. CONCLUSIONS Non-pharmacological noise-masking interventions such as earbuds may improve daily sleepiness, tension, and perceived sleep quality in health care shift workers. Larger studies are needed to determine this interventions’ effect on other populations of shift workers, post-night shift alertness, users long-term physical and mental health, and on patient outcomes.