Sleep Medicine 12 (2011) 808–810

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Sleep Medicine

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Brief Communication

Excessive daytime sleepiness among attending physicians: A pilot survey studyat an academic institution

Rajinder Singh b, Nidhi S. Undevia c, Catherine Schuman d, Hrayr Attarian a,⇑a Department of Neurology, Northwestern University, Chicago, IL, United Statesb Department of Neurology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL, United Statesc Department of Medicine, Loyola University Chicago, Stritch School of Medicine, Maywood, IL, United Statesd Department of Psychiatry, Harvard Medical School, Boston, MD, United States

a r t i c l e i n f o

Article history:Received 29 October 2010Received in revised form 13 April 2011Accepted 25 April 2011Available online 12 June 2011

Keywords:Attending physicianSleepinessEpworthWork hoursHours of sleep per nightEmail surveyResident physicians

1389-9457/$ - see front matter � 2011 Elsevier B.V. Adoi:10.1016/j.sleep.2011.04.003

⇑ Corresponding author. Address: 710 N Lake Shor60611, United States. Tel.: +1 312 9081024; fax: +1 3

E-mail address: hattaria@nmff.org (H. Attarian).

a b s t r a c t

The purpose of this study is to assess excessive daytime sleepiness (EDS) among attending physicians.Emails with an embedded link to an IRB approved questionnaire were sent to attending physicians oftwo closely affiliated academic institutions. An online hospital directory was used to compile a list ofactive attending physicians who practiced clinical medicine. Two additional reminder emails, about2 weeks apart, were also sent. Data were collected anonymously and participation was voluntary. Threehundred fifteen responses out of 506 emails were returned (responder rate of 62.2%). The average agewas 47 years and the majority was married with children. The mean Epworth Sleepiness Scale scorewas six and only 50 (15.9%) physicians were sleepy with a score of >10. Only working longer hours(p = 0.014), habitual napping (p = 0.01) and the feeling of not getting enough sleep (p = 0.01) significantlycorrelated with daytime sleepiness. Hours at work, however, did not correlate with hours of sleep, andthe latter surprisingly did not correlate with sleepiness. Physicians in our sample were slightly moresleep deprived than the general population but not as sleep deprived as resident physicians.

� 2011 Elsevier B.V. All rights reserved.

1. Introduction

Excessive daytime sleepiness (EDS) among resident physiciansand its impact on patient care, the resident’s own health and qual-ity of life is well documented [1–3]. There are also a handful ofstudies on nurses [4–6] and shift working physicians [7,8]. Onlytwo larger scale studies exist looking at prevalence of sleep habitsand daytime sleepiness among physicians but both had low re-sponder rates: 39.6% (341/861) [9] and 45% (180/401) [10].

The purpose of this current study was to assess the prevalenceof excessive daytime sleepiness (EDS) among attending physiciansat a Chicagoland area tertiary academic medical center, to look forvariables that impact the center, and to get a higher response rateand therefore more valid correlations.

2. Methods

An Internal Review Board approved questionnaire (see Fig. 1) onSurvey Monkey was emailed to attending physicians of two affili-ated academic institutions. Also included in the survey was an Ep-

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e Drive 5th Floor, Chicago, IL12 9085073.

worth Sleepiness Scale (ESS). An online hospital directory was usedto compile a list of active attending physicians who practiced clin-ical medicine. Those entirely in research and in basic sciencedepartments were excluded. Two additional reminder emailsabout 2 weeks apart were sent to maximize yield. Data were col-lected anonymously and participation was voluntary. We did notinclude gender in our questionnaire as the two previous surveyshave shown that sex has no impact on sleep habits and prevalenceof excessive daytime sleepiness among attending physicians [9,10].

3. Results

3.1. Demographics

There were 506 total surveys sent (339 male and 167 female)and 315 responses were returned with a 62.2% response rate (39of the recipients worked shift work either in the ED or as hospital-ists). See Table 1 for demographics and substance use results.

3.2. Sleep and work habits

Two (0.6%) were working <20 h/week, 33 (10.5%) 20–40 h/week,173 (54.9%) 40–60 h/week, and 107 (34%) were working >60 h/week. Seventy-five (23.8%) slept <6 h/night, 148 (47%) 6–7 h/night,

Fig. 1. The IRB questionnaire emailed to the subjects.

Table 1Demographic and substance use results.

Age Marital status Children Substance use Caffeine

Average age 47 262 (83.2%) Married or partnered 127 (40.3%) No children 30 (9.5%) Regular sleep aid use 75 (23.8%) <1 Caffeinated drinkRange 33–71 38 (12.1%) Single 53 (16.8%) One child 25 (7.9%) Stimulant use 151 (47.9%) 1–2 Drinks

10 (3.1%) Divorced 93 (29.6%) Two children 1 (0.3%) Recreational drugs 50 (15.9%) 3–4 Drinks5 (1.6%) Did not indicate 42 (13.3%) >2 Children 39 (12.4%) >4 A day

R. Singh et al. / Sleep Medicine 12 (2011) 808–810 809

84 (26.7%) 7–8 h/night and 8 (2.5%) >8 h/night. One hundred andeighty-six (59%) took night call. Six (1.9%) reported having a sleepdisorder, 130 (41.3%) felt they got enough sleep and 40 (12.7%) re-ported napping daily. All worked with residents as it is a teachingmedical center.

3.3. Epworth Sleepiness Scale (ESS)

There were 307 complete and valid responses with an averagescore of 6/24 (normal is <10/24); 50 (15.9%) had an ESS >10, 3(0.95%) of whom had ESS >18.

3.4. Statistical Analysis

Using Minitab 15 software we ran a one-way ANOVA to deter-mine the correlation between ESS and different variables. EDSamong physicians correlated significantly only with habitual nap-ping (p = 0.01), with a subjective sense of not getting enough sleep(p = 0.01), and with actual hours of work per week (p = 0.014) butsurprisingly not with number of hours slept per night (p = 0.27).This, in turn, did not correlate with weekly hours of work(p = 0.97). Neither EDS nor hours slept per night correlated withnumber of children, marital status or age.

4. Discussion

This is, to our knowledge, the only survey with a response ratehigher than 60% (62.2%). In our sample 15.9% were sleepy duringthe day (ESS >10) and mean ESS was six. This prevalence is slightlyhigher than the general population (9.2–12%) [11–13]. In our pre-vious survey the mean ESS was six as well, and the prevalence ofEDS was 12.5% which was not significantly higher than the generalpopulation [9]. The responder rate, however, was lower [14]. Chenet al. [10] reported a mean ESS of 7.8 and a prevalence of EDS of23% (slightly higher than our population) but theirs included bothacademic and private practice physicians in addition to a lower re-sponder rate of 45%. In all these surveys the prevalence of EDSamong attending physicians was significantly lower than that re-ported among resident physicians at 84% [15].

EDS among physicians correlated significantly with habitualnapping, with a subjective sense of not getting enough sleep andwith actual hours of work per week but surprisingly not with num-ber of hours slept per night. This is different than what the previ-ous two studies found. Both found that EDS correlated with hoursslept at night and habitual napping but not with hours of work perweek [9,10]. This may also suggest that in our population, the sub-jective feeling of not getting enough sleep and habitual nappingmay be as good an indicator of EDS as ESS.

Habitual napping may explain why there was a lack of correla-tion between subjective sleepiness and hours of sleep per night.Subjects in our sample who slept less hours per night may have

810 R. Singh et al. / Sleep Medicine 12 (2011) 808–810

been napping during the day to make up for their sleep depriva-tion; therefore, although the number of hours at night was less,this did not correlate with EDS. It could also be that physicians inour sample were more tolerant to sleep deprivation and thereforedid not feel the impact of it in the form of EDS. Although inter-indi-vidual differences exist, there is no evidence that only by the virtueof their profession physicians are more resistant to sleep depriva-tion [16]. On the other hand, working longer hours has made ourphysicians feel subjectively sleepy and this may be attributableto a sense of fatigue which often is difficult to differentiate fromsleepiness [17].

We failed to find any significant relationship between hoursslept at night and number of hours worked. It may be that amountof sleep is not only the function of hours worked but that there areother reasons that may affect total sleep time. Our questionnairedid not address how much awake time physicians spend doingthings that are not work related. We did not further break downwork hours to >60 but <80 and >80 h or even >100 h. In addition,we did not collect data on frequency of calls. Taking night callsper se did not correlate with EDS or average hours of sleep. Theseissues may explain the difference between our findings and thoseon the previous two surveys. Number of children in the generalpopulation is correlated with degree of EDS [18]. We did not findthis in our study but we did not inquire the average age of the chil-dren or the availability of help at home. The average age of partic-ipants was 47 years; therefore the majority of the children weremost likely old enough to sleep through the night and not disrupttheir parents’ sleep.

Furthermore, the amount of caffeine consumption did not haveany significant correlation with EDS or amount of sleep per night.According to Sanchez-Ortuno et al. not only did caffeine consump-tion not correlate with degree or prevalence of EDS but it did notcorrelate with reduced TST in middle age French working popula-tion. This could be due to tolerance to the effects of caffeine. An-other factor is the timing of the caffeine intake during the daythat neither our study nor the other study addressed [12].

The strengths of our study include highest responder rate of thefew published studies targeting physicians. We used the ESS, a wellvalidated scale, and we designed a questionnaire that was simpleand without much room for free text. Our population was moreuniform, working at the same center and geographic location, withthe help of residents and only a small percentage of them doingshift work. This helps eliminate geographic and type-of-practicevariables.

The weaknesses of this study are small sample size, use of his-toric controls, using ESS as a measure rather than a comparison tothe level of resident sleepiness [19], restricted population and lackof gender differentiation. General population studies, however,have significant gender differences when assessing EDS [18]. Wealso did not ask about the timing of caffeine, the average age ofchildren, the availability of help with child care, or the specialtiesof the physicians taking the survey in order to keep the question-naire simple. Since this is a pilot survey we did not include any pri-vate practitioners. We did not specifically look at the 39 recipientswho worked shift work and compare their ESS values with the lar-ger group. Lastly, we did not question physicians about the type ofsleep aids and about the different sleep disorder related symptomsthey may have. Overall, we found that attending physicians at thistertiary academic center were slightly sleepier than the generalpopulation but significantly less so than resident physicians. With-out having looked at the impact of sleepiness on the physician’sperformance and error rate we cannot comment whether the15.8% EDS is acceptable or even the norm for physicians. It is well

known that at high levels of EDS performance is impaired but low-er education levels, motivation and other factors play a bigger role[20]. We also found a positive relationship between working longerhours, habitual napping and being sleepy during the day. No rela-tionship was found between hours worked during the day andhours slept at night. We hope that this will increase awarenessof sleep deprivation among physicians and will lead to larger sur-veys that will include private practice and academic physicians andwill have active controls among residents and the generalpopulation.

Conflict of Interest

The ICMJE Uniform Disclosure Form for Potential Conflicts ofInterest associated with this article can be viewed by clicking onthe following link: doi:10.1016/j.sleep.2011.04.003.

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