Excessive Sleepiness and Self-Reported Shift Work Disorder: An Internet Survey of Shift Workers

Objectives: To compare excessive sleepiness and quality of life (QoL) scores in shift workers who report having a diagnosis of shift work disorder (SWD) with those who report having no such diagnosis. Methods: An Internet-based survey was conducted between March and April 2009 that included shift workers with or without a self-reported diagnosis of SWD. Participation required working >= 21 hours/week for 2 weeks prior, a diagnosis of SWD or a score of >= 10 on the Epworth Sleepiness Scale, and a score of >= 5 on any subscale of the Sheehan Disability Scale. Results: Surveys included 260 shift workers (103 with an SWD diagnosis and 157 without an SWD diagnosis). Diagnosed and undiagnosed respondents demonstrated similar Epworth Sleepiness Scale (13.7 vs 13.6, respectively) and Karolinska Sleepiness Scale (6.0 vs 5.5, respectively) scores. Sheehan Disability Scale social life and family life scores were similar between the 2 groups, although diagnosed respondents had a greater mean Sheehan Disability Scale work disability score compared with undiagnosed respondents (6.7 vs 5.5; P < 0.0001). Quality of life was more impaired in diagnosed patients in terms of ability to drive safely, propensity for accidents, work performance, and anxiety (P <= 0.039 vs undiagnosed). Work-related accidents (16% vs 5%; P = 0.0076) and injuries at work (17% vs 7%; P = 0.0233) were also reported by more diagnosed respondents than by undiagnosed respondents. Many respondents used caffeine and 57% of diagnosed respondents received prescription medication to treat symptoms of SWD. Conclusion: Individuals with diagnosed SWD demonstrated impairment in QoL and reported more work-related accidents and injuries, although many measures of QoL and prescription drug use were similar between groups. Shift work disorder is underrecognized by clinicians and patients, resulting in undertreatment, despite the availability of several behavioral and therapeutic treatment options.