Jason P. Sullivan

Sleep Disorders, Health, and Safety in Police Officers

CONTEXT Sleep disorders often remain undiagnosed. Untreated sleep disorders among police officers may adversely affect their health and safety and pose a risk to the public. OBJECTIVE To quantify associations between sleep disorder risk and self-reported health, safety, and performance outcomes in police officers. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional and prospective cohort study of North American police officers participating in either an online or an on-site screening (n=4957) and monthly follow-up surveys (n=3545 officers representing 15,735 person-months) between July 2005 and December 2007. A total of 3693 officers in the United States and Canada participated in the online screening survey, and 1264 officers from a municipal police department and a state police department participated in the on-site survey. MAIN OUTCOME MEASURES Comorbid health conditions (cross-sectional); performance and safety outcomes (prospective). RESULTS Of the 4957 participants, 40.4% screened positive for at least 1 sleep disorder, most of whom had not been diagnosed previously. Of the total cohort, 1666 (33.6%) screened positive for obstructive sleep apnea, 281 (6.5%) for moderate to severe insomnia, 269 (5.4%) for shift work disorder (14.5% of those who worked the night shift). Of the 4608 participants who completed the sleepiness scale, 1312 (28.5%) reported excessive sleepiness. Of the total cohort, 1294 (26.1%) reported falling asleep while driving at least 1 time 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. An analysis of up to 2 years of monthly follow-up surveys showed that those respondents who screened positive for a sleep disorder vs those who did not had a higher rate of reporting that they had made a serious administrative error (17.9% vs 12.7%; adjusted odds ratio [OR], 1.43 [95% CI, 1.23-1.67]); of falling asleep while driving (14.4% vs 9.2%; adjusted OR, 1.51 [95% CI, 1.20-1.90]); of making an error or safety violation attributed to fatigue (23.7% vs 15.5%; adjusted OR, 1.63 [95% CI, 1.43-1.85]); and of exhibiting other adverse work-related outcomes including uncontrolled anger toward suspects (34.1% vs 28.5%; adjusted OR, 1.25 [95% CI, 1.09-1.43]), absenteeism (26.0% vs 20.9%; adjusted OR, 1.23 [95% CI, 1.08-1.40]), and falling asleep during meetings (14.1% vs 7.0%; adjusted OR, 1.95 [95% CI, 1.52-2.52]). CONCLUSION Among a group of North American police officers, sleep disorders were common and were significantly associated with increased risk of self-reported adverse health, performance, and safety outcomes.

Common sleep disorders increase risk of motor vehicle crashes and adverse health outcomes in firefighters

STUDY OBJECTIVES Heart attacks and motor vehicle crashes are the leading causes of death in US firefighters. Given that sleep disorders are an independent risk factor for both of these, we examined the prevalence of common sleep disorders in a national sample of firefighters and their association with adverse health and safety outcomes. METHODS Firefighters (n = 6,933) from 66 US fire departments were assessed for common sleep disorders using validated screening tools, as available. Firefighters were also surveyed about health and safety, and documentation was collected for reported motor vehicle crashes. RESULTS A total of 37.2% of firefighters screened positive for any sleep disorder including obstructive sleep apnea (OSA), 28.4%; insomnia, 6.0%; shift work disorder, 9.1%; and restless legs syndrome, 3.4%. Compared with those who did not screen positive, firefighters who screened positive for a sleep disorder were more likely to report a motor vehicle crash (adjusted odds ratio 2.00, 95% CI 1.29-3.12, p = 0.0021) and were more likely to self-report falling asleep while driving (2.41, 2.06-2.82, p < 0.0001). Firefighters who screened positive for a sleep disorder were more likely to report having cardiovascular disease (2.37, 1.54-3.66, p < 0.0001), diabetes (1.91, 1.31-2.81, p = 0.0009), depression (3.10, 2.49-3.85, p < 0.0001), and anxiety (3.81, 2.87-5.05, p < 0.0001), and to report poorer health status (p < 0.0001) than those who did not screen positive. Adverse health and safety associations persisted when OSA and non-OSA sleep disorders were examined separately. CONCLUSIONS Sleep disorders are prevalent in firefighters and are associated with increased risk of adverse health and safety outcomes. Future research is needed to assess the efficacy of occupational sleep disorders prevention, screening, and treatment programs in fire departments to reduce these safety and health risks.

Circadian misalignment affects sleep and medication use before and during spaceflight

Sleep deficiency and the use of sleep-promoting medication are prevalent during spaceflight. Operations frequently dictate work during the biological night and sleep during the biological day, which contribute to circadian misalignment. We investigated whether circadian misalignment was associated with adverse sleep outcomes before (preflight) and during spaceflight missions aboard the International Space Station (ISS). Actigraphy and photometry data for 21 astronauts were collected over 3,248 days of long-duration spaceflight on the ISS and 11 days prior to launch (n=231 days). Sleep logs, collected one out of every 3 weeks in flight and daily on Earth, were used to determine medication use and subjective ratings of sleep quality. Actigraphy and photometry data were processed using Circadian Performance Simulation Software to calculate the estimated endogenous circadian temperature minimum. Sleep episodes were classified as aligned or misaligned relative to the estimated endogenous circadian temperature minimum. Mixed-effects regression models accounting for repeated measures were computed by data collection interval (preflight, flight) and circadian alignment status. The estimated endogenous circadian temperature minimum occurred outside sleep episodes on 13% of sleep episodes during preflight and on 19% of sleep episodes during spaceflight. The mean sleep duration in low-Earth orbit on the ISS was 6.4±1.2 h during aligned and 5.4±1.4 h (P<0.01) during misaligned sleep episodes. During aligned sleep episodes, astronauts rated their sleep quality as significantly better than during misaligned sleep episodes (66.8±17.7 vs. 60.2±21.0, P<0.01). Sleep-promoting medication use was significantly higher during misaligned (24%) compared with aligned (11%) sleep episodes (P<0.01). Use of any medication was significantly higher on days when sleep episodes were misaligned (63%) compared with when sleep episodes were aligned (49%; P<0.01). Circadian misalignment is associated with sleep deficiency and increased medication use during spaceflight. These findings suggest that there is an immediate need to deploy and assess effective countermeasures to minimize circadian misalignment and consequent adverse sleep outcomes both before and during spaceflight.

Assessment of Drowsiness Based on Ocular Parameters Detected by Infrared Reflectance Oculography

STUDY OBJECTIVES Numerous ocular parameters have been proposed as reliable physiological markers of drowsiness. A device that measures many of these parameters and then combines them into a single metric (the Johns Drowsiness Scale [JDS]) is being used commercially to assess drowsiness in professional drivers. Here, we examine how these parameters reflect changes in drowsiness, and how they relate to objective and subjective indices of the drowsy state in a controlled laboratory setting. DESIGN A within subject prospective study. PARTICIPANTS 29 healthy adults (18 males; mean age 23.3 ± 4.6 years; range 18-34 years). INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Over the course of a 30-h extended wake vigil under constant routine (CR) conditions, participants were monitored using infrared reflectance oculography (Optalert) and completed bi-hourly neurobehavioral tests, including the Karolinska Sleepiness Scale (KSS) and Psychomotor Vigilance Task (PVT). Ocular-defined increases in drowsiness were evident with extended time awake and during the biological night for all ocular parameters; JDS being the most sensitive marker of drowsiness induced by sleep regulatory processes (p < 0.0001). In addition, the associations between JDS in the preceding 10-min period and subsequent PVT lapses and KSS were stronger (AUC 0.74/0.80, respectively) than any other ocular metric, such that PVT lapses, mean response time (RT), and KSS increased in a dose-response manner as a function of prior JDS score (p < 0.0001). CONCLUSIONS Ocular parameters captured by infrared reflectance oculography detected fluctuations in drowsiness due to time awake and during the biological night. The JDS outcome was the strongest predictor of drowsiness among those tested, and showed a clear association to objective and subjective measures of drowsiness. Our findings indicate this real-time objective drowsiness monitoring system is an effective tool for monitoring changes in alertness and performance along the alert-drowsy continuum in a controlled laboratory setting.

Implementing a Sleep Health Education and Sleep Disorders Screening Program in Fire Departments: A Comparison of Methodology

Objective: The objective of this study is to compare three methods of administering a sleep health program (SHP) in fire departments. Methods: An SHP, comprising sleep health education and screening for common sleep disorders, was implemented in eight fire departments using three approaches: expert-led, train-the-trainer, and online. Participation rates, knowledge assessments, surveys, and focus group interviews were analyzed to assess the reach and effectiveness of the methodologies. Results: The Expert-led SHP had the highest participation rate, greatest improvement in knowledge scores, and prompted more firefighters to seek clinical sleep disorder evaluations (41%) than the other approaches (20 to 25%). Forty-two percent of focus group participants reported changing their sleep behaviors. Conclusion: All approaches yielded reasonable participation rates, but expert-led programs had the greatest reach and effectiveness in educating and screening firefighters for sleep disorders.

Behaviorally-determined sleep phenotypes are robustly associated with adaptive functioning in individuals with low functioning autism

Despite sleep disturbance being a common complaint in individuals with autism, specific sleep phenotypes and their relationship to adaptive functioning have yet to be identified. This study used cluster analysis to find distinct sleep patterns and relate them to independent measures of adaptive functioning in individuals with autism. Approximately 50,000 nights of care-giver sleep/wake logs were collected on school-days for 106 individuals with low functioning autism (87 boys, 14.77 ± 3.11 years) for 0.5–6 years (2.2 ± 1.5 years) from two residential schools. Using hierarchical cluster analysis, performed on summary statistics of each individual across their recording duration, two clusters of individuals with clearly distinguishable sleep phenotypes were found. The groups were summarized as ‘unstable’ sleepers (cluster 1, n = 41) and ‘stable’ sleepers (cluster 2, n = 65), with the former exhibiting reduced sleep duration, earlier sleep offset, and less stability in sleep timing. The sleep clusters displayed significant differences in properties that were not used for clustering, such as intellectual functioning, communication, and socialization, demonstrating that sleep phenotypes are associated with symptom severity in individuals with autism. This study provides foundational evidence for profiling and targeting sleep as a standard part of therapeutic intervention in individuals with autism.

Sleep patterns predictive of daytime challenging behavior in individuals with low-functioning autism

Increased severity of problematic daytime behavior has been associated with poorer sleep quality in individuals with autism spectrum disorder. In this work, we investigate whether this relationship holds in a real‐time setting, such that an individuals prior sleep can be used to predict their subsequent daytime behavior. We analyzed an extensive real‐world dataset containing over 20,000 nightly sleep observations matched to subsequent challenging daytime behaviors (aggression, self‐injury, tantrums, property destruction and a challenging behavior index) across 67 individuals with low‐functioning autism living in two U.S. residential facilities. Using support vector machine classifiers, a statistically significant predictive relationship was found in 81% of individuals studied (P < 0.05). For all five behaviors examined, prediction accuracy increased up to approximately eight nights of prior sleep used to make the prediction, indicating that the behavioral effects of sleep may manifest on extended timescales. Accurate prediction was most strongly driven by sleep variability measures, highlighting the importance of regular sleep patterns. Our findings constitute an initial step towards the development of a real‐time monitoring tool to pre‐empt behavioral episodes and guide prophylactic treatment for individuals with autism. Autism Res 2018, 11: 391–403.

Cross-sectional analysis of sleep-promoting and wake-promoting drug use on health, fatigue-related error, and near-crashes in police officers

Objectives To examine sleep-promoting and wake-promoting drug use in police officers and associations between their use and health (excessive sleepiness, stress and burnout), performance (fatigue-related errors) and safety (near-crashes) outcomes, both alone and in combination with night-shift work. Design Cross-sectional survey. Setting Police officers from North America completed the survey either online or via paper/pencil at a police station. Participants 4957 police participated, 3693 online (91.9%, participation rate) and 1264 onsite (cooperation rate 63.1%). Main outcome measures Sleep-promoting and wake-promoting drug use, excessive sleepiness, near-crash motor vehicle crashes, dozing while driving, fatigue errors, stress and burnout. Results Over the past month, 20% of police officers reported using sleep-promoting drugs and drugs causing sleepiness, while wake-promoting agents were used by 28% of police (5% used wake-promoting drugs, 23% used high levels of caffeine and 4% smoked to stay awake). Use of sleep-promoting drugs was associated with increased near-crashes (OR=1.61; 95% CI 1.21 to 2.13), fatigue-related errors (OR=1.75; 95% CI 1.32 to 2.79), higher stress (OR=1.41; 95% CI 1.10 to 1.82), and higher burnout (OR=1.83; 95% CI 1.40 to 2.38). Wake-promoting drug use, high caffeine and smoking to stay awake were associated with increased odds of a fatigue-related error, stress and burnout (ORs ranging from 1.68 to 2.56). Caffeine consumption was common, and while smoking was not, of those participants who did smoke, one-in-three did so to remain awake. Night-shift work was associated with independent increases in excessive sleepiness, near-crashes and fatigue-related errors. Interactions between night-shift work and wake-promoting drug use were also found for excessive sleepiness. Conclusions Police who use sleep-promoting and wake-promoting drugs, especially when working night shifts, are most vulnerable to adverse health, performance and safety outcomes. Future research should examine temporal relationships between shift work, drug use and adverse outcomes, in order to develop optimal alertness management strategies.