Sleep Disorders

Shift Work Disorder

Clinical Characteristics
Shift work is a term that applies to a broad spectrum of non-standard work schedules ranging from occasional on-call overnight duty, to rotating schedules, to steady, permanent night work. It can also apply to schedules demanding an early awakening from nocturnal sleep. The heterogeneity of work schedules makes it very difficult to generalize about shift work. 21

Shift work disorder (SWD) is one of the circadian rhythm sleep disorders. SWD causes impairment during scheduled shift work due to insomnia or excessive sleepiness. The LEO with SWD may be first recognized by peers or supervisors who observe somnolence, sudden incapacitation, or erratic job performance (see Appendix C).

SWD is caused by enforcing an artificial pattern of sleep and wakefulness that is misaligned with the body’s internal circadian rhythm.22 It should be noted that the underlying cause of SWD in LEOs is not medical; it is due to administrative policies and demands of the law enforcement profession.

Some individuals cannot adequately adapt to the challenges to the physiologic stresses of shift work and cannot competently perform all essential job tasks. This is the operational basis for the diagnosis of SWD.

Reduced alertness may occur during the work shift and also during off-duty awake hours. This reduced alertness may impair situational awareness, executive functioning and vigilance. Also, major portions of the individual’s free time may have to be used for recovery of sleep, which in many cases will have negative social consequences.23 Persons with SWD have been found to have higher rates of sleepiness-related accidents, ulcer disease, and depression than workers on the same schedule who do not have SWD.24

Diagnostic Tests
SWD in the LEO may be first recognized by family members, peers, or supervisors who observe somnolence or erratic job performance. SWD is a clinical diagnosis that generally does not require formal sleep lab studies such as a polysomnogram or a multiple sleep latency test. Sleep-wake diaries (sleep logs) are recommended as a method for evaluating sleep schedules in LEOs suspected as having SWD.

SWD should be suspected in LEO shift workers, particularly those who work between 9:00 pm and 6:00 am, who report excessive sleepiness and impairment during night work hours or insomnia during day sleep periods. Symptoms improve during periods of day work or time off from work.20

Treatment of SWD
A comprehensive review of treatment strategies involving changes in sleep hygiene practices or bright light therapy is beyond the scope of this document. However, several non-prescription approaches have been shown to be useful, including judicious use of caffeine (a highly effective alerting agent), prophylactic napping prior to work shift, use of melatonin for improved sleep during the day, and bright light exposure at the beginning of the work shift (see Appendix F – Sleep Hygiene and Shift Work: Suggested Checklist).

As for pharmacologic therapy, the military has treated SWD with medications such as caffeine and dexamphetamine. Modafinil (Provigil) is approved by the U.S. Air Force for use by pilots during flights of long duration.18,25 It is used when other strategies to allow rest periods (e.g., supplemental air crews) are not feasible. When given prophylactically in repeated doses, modafinil has been shown to improve alertness and performance in a simulator test of sleep-deprived army helicopter pilots.26 Armodafinil (Nuvigil), which has a longer half-life than modafinil, has been evaluated to treat sleep SWD. One randomized controlled study concluded that armodafinil “significantly improved wakefulness during scheduled night work… (and) significantly improved measures of overall clinical condition, long-term memory, and attention.”27 However, it is unclear whether these performance measures are generalizable to LEO essential job functions, particularly time-critical decision making (e.g., use of deadly force).

Selected LEO-Specific Clinical Studies and Reports
Garbarino S, De Carli F, Nobili L, et al. Sleepiness and sleep disorders in shift workers: a study on a group of Italian police officers. Sleep. 2002;25(6):648-53.28

In this study, 1280 police officers – 611 shift workers (SW), 669 non-shift workers (NSW) – completed questionnaires that collected demographics, biometrics, working conditions, sleep problems, and accidents. Sleepiness was characterized by responses to the Epworth; sleep problems were characterized by a sleep disorders score (SDS). While the study did not find the ESS score to be higher in SW than in NSW, the SDS was significantly influenced by shift-work conditions and seniority in shift work. Sleep-ascribed accidents were significantly increased in the SW group and related to the presences of sleep disorders. The authors found evidence of sleep disorders in 35.7% of SW and 26.3% of NSW.

Rajaratnam SM, Barger LK, Lockley SW, et al. Sleep disorders, health and safety in police officers. JAMA. 2011;306(23):2567-78.2

This cohort study of 4,957 participating North American LEOs using a self-administered survey, identified approximately 14.5% of those who worked night shift as screening positive for SWD. This study found that 40.4% of LEOs, who had not been diagnosed previously, screened positive for at least 1 sleep disorder. Of the total cohort, 1,666 (33.6%) screened positive for OSA; 281 (6.5%) for moderate to severe insomnia; and 269 (5.4%) for shift work disorder (14.5% of those who worked the night shift). In addition, of the 4,608 LEOs who completed the sleepiness scale, 1,312 (28.5%) reported excessive sleepiness. Of the total cohort, 1,294 (26.1%) reported falling asleep while driving at least once a month. Respondents who screened positive for obstructive sleep apnea or any sleep disorder had an increased prevalence of reported physical and mental health conditions, including diabetes, depression, and cardiovascular disease. Two years of monthly follow-up surveys showed that LEOs who screened positive for a sleep disorder (versus those who did not) reported a higher rate of: making a serious administrative error (17.9% versus 12.7%); falling asleep while driving (14.4% versus 9.2%); making an error or safety violation attributed to fatigue (23.7% versus 15.5%); and exhibiting other adverse work-related outcomes including uncontrolled anger toward suspects (34.1% versus 28.5%), absenteeism (26.0% versus 20.9%;), and falling asleep during meetings (14.1% versus 7.0%).

Fitness-for-Duty Criteria
The “boundary between a ‘normal response’ to the rigors of night work, and a diagnosable disorder (such as SWD) is not sharp.”17 Ideally, the diagnosis of SWD and ongoing evaluation of response to treatment should be confirmed in a structured, multidisciplinary evaluation by a clinician formally credentialed in sleep medicine, the police physician, and supervisors. For the LEO with SWD, the police physician should advise the agency that performance issues are unlikely to improve if they continue to work between 9pm and 6am. The LEO with confirmed SWD who does not adequately respond to medical management should be subject to appropriate work restrictions.