Sleep diaries for shift workers

Introduction Sleep diaries have long been the preferred method for collecting data on self-reported sleep over time in insomnia research. Only a few studies were dedicated to daily self-reports of sleep difficulties associated with shift work. The aim of this study is to qualitatively document the use of sleep diaries in the context of shift work and to present a diary template that reflects the reality of shift work. Materials and methods The sample included 46 shift workers (86.9% women; mean age = 35.4 years old) taking part in a study on bio-psychosocial factors involved in the evolution of shift work sleep disorder. Among them the first 10 were given a sleep diary used in previous insomnia studies. This sleep diary consisted of 7-day report presented on a single page with a column for each day of the week. This format is similar to the one proposed recently as a consensus sleep diary by a committee of experts. The other 36 participants received a diary with a 24-h scale on each page. Both sleep diaries included 6 questions on sleep and wake time, and a question on medication, alcohol and caffeine use. Both formats used a sleepiness rating scale (Likert scale from “1” to “7”) to be completed after each sleeping period. Results 55.5% of the total sample (26 out of 46 participants) reported at least 3 sleep periods per day when working at night, 41.3% reported 2 sleep periods per day and only 1 participant reported 1 sleep period per day. The first 10 participants were unable to comply with the 7 columns for each day of the week diary. All of them reported that this version did not reflect the reality of their sleep schedules. A few added an extra column in order to report transitions before and after night shift. Most of them did not report napping periods as they consider that they had more than one sleep period per day rather than a nap. Most of them wanted to comment on their sleep difficulties occurring at different time point. The 36 participants using the second sleep diary format did not report any of these difficulties. Conclusion Qualitative reports suggest that within the context of shift work, sleep diaries need to be adjusted in order to capture the sleep patterns over 24 h. Moreover, this tool will help clinicians to better investigate difficulties with sleep in the shift work population and to develop a treatment plan that better suits the reality of shift work sleep disorder. Acknowledgement Supported by the Canadian Institutes of Health Research (#197171).