Sleep Deprivation in Cardiology: A Multidisciplinary Survey

Abstract: Background. The burden and impact of sleep deprivation in cardiology has received limited study. Methods. A multidisciplinary, online survey on sleep health patterns and sleep deprivation involving 44 closed-ended questions was distributed via email list to cardiovascular workers. Results. The survey was circulated among 6683 individuals, of whom 481 (7.2%) completed the survey; 80% of the respondents were men and 70% were interventional cardiologists. Nearly all (91%) had call responsibilities, with 43% doing ≥7 call-nights per month. Sleep disorders were reported in 25%, with 25% using sleep-inducing medications (8.4% at least once per week). The main factors diminishing the quality and/or quantity of sleep were related to work (66%), family and/or personal activities (56%), and staying up late at night writing or studying (48%). Sleep deprivation was associated with difficulty concentrating (58%), lack of motivation (56%), and irritability (68%). Work performance was felt to be hindered by 46% of participants and 8.6% reported an adverse event such as a complication and/or negative patient outcome likely related to sleep deprivation. Many (56.5%) felt burnout and 85% opined that policies should exist allowing sleep-deprived individuals to go home early post call. Conclusions. Our survey provides insights into sleep health patterns among cardiovascular workers and potential factors contributing to sleep deprivation. Sleep deprivation may impact performance, with 8.6% of respondents describing sleep-deprivation related adverse events. Further study is required to both identify measures to attenuate the burden and better understand the impact of sleep deprivation on both health-care personnel and patient outcomes.

J INVASIVE CARDIOL 2019;31(6):195-198. Epub 2019 April 15.

Key words: cognitive function, fatigue, practice management

Sleep deprivation, defined as a reduction in usual total sleep time and categorized as either acute or chronic when affecting individuals for at least 3 months, is a frequent problem that has been reported to affect 35%-40% of adults in the United States.^1-4 It has been associated with adverse health outcomes, and reported to potentially impact regular activities, including work performance.^1-3 Health-care workers, such as physicians, nurses, and technicians, are at increased risk for sleep deprivation because of the nature of their work, often working long hours or around the clock to provide patient care.

The impact of sleep deprivation among health-care workers has been mostly examined among medical trainees, to determine optimal resident-physician work hours.^4-7 Less is known about the impact of sleep deprivation on cardiovascular practice, with most studies in the field of cardiology focused on patient outcomes following percutaneous coronary intervention (PCI) based on the presence or absence of sleep deprivation among interventional cardiologists performing such procedures.^8-10

To improve our understanding of the burden and impact of sleep deprivation on cardiology, we developed a multidisciplinary, online-based survey focused on sleep health patterns and sleep deprivation.

Methods

We designed a closed-ended survey and circulated a link to a 44-item questionnaire (Supplemental Table S1) from September through December 2017 to 6683 cardiovascular workers in the United States, including physicians (eg, invasive and non-invasive cardiologists, interventional cardiologists, cardiovascular surgeons), advanced practice providers (nurse practitioners and physician assistants), nurses, technicians, sonographers, and cardiovascular fellows. Following study completion, anonymized summary data and individual responses were examined using an online survey development cloud-based software (SurveyMonkey, Inc).

Results

The survey was circulated among 6683 individuals, of which 481 (7.2%) completed the survey. Respondents were mostly men (80%), and most (81%) were between 31 and 60 years old. Most were interventional cardiologists (70%), followed by 8.5% responding as “other,” and general or non-invasive cardiologists and registered nurses (each representing 7.7% of the cohort). Summary data for the entire completed survey are provided in Supplemental Table S1.

Over half of respondents (58%) had more than 10 years of experience in their respective practice, while 19% were in the early phases of their career (0 to 5 years in practice) and 7% were in training. The majority of respondents had night-call responsibilities (91%), with 438 (approximately 47%) having night-call responsibilities averaging ≥7 calls per month, and most (79%) doing home-call plus in-house call for emergencies (such as cardiac catheterization laboratory activation).

If there was limited opportunity for sleep during call due to work-related activities, only 16% reported being able to go home early the following day, with most (69%) not being able to go home and 15% with unique situations. Among the 15% with unique situations, responses included the ability to go home early post call depending on the day’s schedule (number of cases scheduled) and whether a partner was available to offer coverage. Some reported being able to leave at noon, and others reported the ability to go home when scheduled work was completed (eg, cases, procedures, rounding), among others.

Regarding sleep health patterns, 118/481 respondents (25%) reported suffering from a sleep disorder (eg, sleep apnea, insomnia) and 25% reported taking sleep-inducing medication (17% rare use, 5% 1-2 times per week, and 3.4% >2 times per week). During weekdays, most (94%) wake up before 7 am, including 55% before 6 am, whereas 69% reported going to bed after 10 pm, including 13% past midnight. Compared with 33% sleeping ≤6 hours during non-call days, 84.5% reporting sleeping ≤6 hours during call days (including 24% sleeping ≤4 hours). Notably, most respondents (74.4%) reported that ≥6 hours are required to function well the next day.

The three most common factors contributing to sleep deprivation were: work-related activities (eg, chart completion) (66%), family and/or personal activities, such as time with children, partners, and/or friends (56%), and staying up late because of other activities, such as writing or studying (48%). Among respondents, 17% attributed caffeine intake as a possible factor diminishing the quantity or quality of sleep. Most respondents (81%) had at least one cup of caffeinated coffee per day, with approximately one-third of individuals drinking ≥3 cups per days. Other factors such as alcohol intake were examined, with 24% consuming alcohol “sometimes” and 6% “often” before going to bed. Digital devices (eg, phone) were frequently used before falling asleep, with 25% using them sometimes and 42% using them often.

Following a night with very limited sleep, respondents reported that the most frequent symptoms were: irritability (68%), difficulty concentrating (58%), lack of motivation (56%), absent-mindedness or forgetfulness (47%), mood swings (44%), increased likelihood of falling slightly asleep (40%), and headaches (36%). In addition, 56% of respondents reported feeling burnout.

Work performance was felt to be hindered by 46% of participants, while only 11% felt that insufficient sleep never affected their work performance. Furthermore, 8.6% of participants reported an adverse event such as a complication and/or negative patient outcome that might have been related to sleep deprivation (Table 1). Among the 41 participants offering further insights into adverse events, responses included procedure-related events such as pacer perforation, failed interventions, coronary dissection, medication dosage errors, and death. Respondents also reported that sleep deprivation was associated with impaired medical decision-making, difficulty with documentation or orders, inclination to stage procedures, and other issues such as motor vehicle accidents (Figure 1). Most respondents (65%) felt that disclosure of any sleep deprivation is not required. Similarly, even though there was limited sleep (awake for more than 22 of the prior 24 hours), 52.2% feel that it is not necessary to disclose such information during consent, while 47.8% feel it should be disclosed.

Discussion

Our multidisciplinary survey offers novel and important insights regarding sleep health patterns and sleep deprivation in cardiovascular workers, in particular interventional cardiologists, who represented over two-thirds of respondents. Our survey indicates that nearly all personnel (91%) involved in cardiovascular care take night call and are, therefore, at risk of sleep deprivation. Most respondents (74.4%) reported that ≥6 hours of sleep are required to function well the next day. The ability to leave early post call, however, is rare (16%), despite 84.5% reporting sleeping ≤6 hours during call day and almost 25% of respondents sleeping ≤4 hours.

What is the potential impact of sleep deprivation? Our survey indicates that several symptoms occur following a night with very limited sleep, such as irritability, difficulty concentrating, and lack of motivation. While the occurrence of these symptoms may not necessarily jeopardize patient care,^8-10 it clearly has the potential to do so, for example, by reducing attention to detail and impacting interpersonal interactions (eg, among coworkers and with patients or family). Importantly, nearly half of respondents (46%) felt that work performance was hindered by sleep deprivation, with 8.6% reporting an adverse event such as a complication and/or negative patient outcome that might have been related to sleep deprivation, including potential events affecting the respondent, such as motor vehicle accidents (Figure 1). 

Cardiovascular studies examining the impact of sleep deprivation have been mostly limited to studies addressing patient outcomes following PCI, suggesting that patient care is not jeopardized by sleep deprivation.^3,8-10 Other studies, however, suggest that sleep deprivation impacts care delivery. For example, Landrigan et al⁴ showed that medical interns working extended work shifts every third night were more likely to make serious medical errors, such as medication or diagnostic errors, than those not working extended work shifts. Similarly, Arnedt et al⁶ showed that after 4 weeks of heavy call, resident attention, vigilance, and simulated driving performance were equivalent or worse than the impairment observed at 0.04-0.05 g% blood alcohol concentration. While PCI studies to date show that measures such as procedural success, mortality, or bleeding are not affected,^8-10 it is not known whether other factors such as medication or diagnostic errors (among others) are affected. Our survey suggests that adverse events potentially related to sleep deprivation may be under-estimated, although we queried for any adverse event during any timeframe and cannot estimate the magnitude or frequency of such events over more specific timeframes.

Our survey illustrates that other factors beyond night call may also influence sleep patterns, with caffeine intake during the day and use of digital devices prior to bedtime frequently reported in our survey. Such factors may potentially affect sleep quantity and/or quality. These issues may affect the entire population, not only cardiovascular workers, but the frequent night-call duties among the latter may amplify the impact of those factors on sleep deprivation.

Recognizing the need to provide patient care around the clock and the risk of sleep deprivation, we asked whether it was necessary for patients to be aware of sleep deprivation among clinicians doing their procedures. The majority of respondents did not feel this was necessary. However, in cases of very limited time for sleep (awake for more than 22 of the prior 24 hours), 52% did feel that disclosure should be considered. In contrast, based on prior PCI outcome investigations showing that sleep deprivation does not affect mortality, procedural success, or complication rates,¹⁰ disclosure may not always be necessary.

Study limitations. Our survey has some limitations. First, the survey completion rate was <10%. Second, it is possible that cardiovascular workers who are more impacted by sleep deprivation could have a greater interest in completing the survey, thus over-estimating the burden and impact of sleep deprivation. Third, 70% of respondents were interventional cardiologists and therefore not reflective of the entire distribution of cardiologist-type practices. Fourth, while our survey offers important insights into the potential impact of sleep deprivation, our analysis cannot address whether any effect is related solely to night call or other potential confounders, including other responsibilities and competing interests such as time with family, other commitments (research, writing, studying, etc) and factors such as caffeine intake and digital device use. Lastly, our adverse event rate included not only patient events but also events directly affecting the respondent, such as motor vehicle accidents.

Conclusion

Cardiovascular workers are prone to sleep deprivation, partly because of frequent call-coverage responsibilities. Our survey elucidates several potential contributing factors, such as underlying sleep disorders, use of digital devices, and caffeinated products. Work-related and/or academic responsibilities are felt to diminish the quality and/or quantity of sleep. Sleep deprivation may impact performance, with 8.6% of those completing the survey reporting deprivation to be associated with adverse events. More study is required to identify measures to attenuate the burden and understand the impact of sleep deprivation on both health-care personnel and patient outcomes.

References

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From the ¹Department of Medical Education, Abbott Northwestern Hospital, Minneapolis, Minnesota; ²Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; ³Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota; and ⁴Cedars Sinai Medical Center, Los Angeles, California.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Brilakis reports consulting/speaker honoraria from Abbott Vascular, Boston Scientific, CSI, Elsevier, GE Healthcare, Medicure, InfraRedX, and Medtronic; research support from Regeneron and Siemens; board of directors for Cardiovascular Innovations Foundation; board of trustees for Society of Cardiovascular Angiography and Interventions. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript submitted January 1, 2019, accepted January 14, 2019.

Address for correspondence: Emmanouil S. Brilakis, MD, PhD, Minneapolis Heart Institute Foundation, 920 East 28th St, Suite 620, Minneapolis, MN 55407. Email: esbrilakis@gmail.com