Nap Time Research Articles

Characteristics of napping in community-dwelling insomnia patients

ObjectiveWe aimed to determine napping characteristics of community-dwelling patients with insomnia disorder (ID) compared to characteristics of normal controls (NC), and to examine the effect of napping on nocturnal sleep. MethodsAdult volunteers who were more than 18 years old were recruited from three rural public health centers in Korea. Data from actigraphy recording and a sleep diary filled out for seven days were obtained. Finally, 115 ID patients and 80 NC subjects were included in this study. Parameters and timing of nocturnal sleep and nap were compared between the ID and NC groups. Two-way analysis of covariance (ANCOVA) was performed to determine the effect of ID diagnosis and napping on sleep parameters. ResultsSleep efficiency (SE) in the ID group was significantly lower (p = 0.010), and wake time after sleep onset (WASO) was significantly greater (p = 0.023), compared to the NC group. There was no significant difference in nocturnal sleep or nap timing between the two groups. Nap frequency in the ID group was significantly higher than that in the NC group (p = 0.025). Although ID diagnosis and napping had no independent effect on fragmentation index, their interaction had a significant effect on fragmentation index (p = 0.021). Nap frequency was positively correlated with PSQI score (r = 0.166, p = 0.033). ConclusionInsomnia patients showed no significant difference in nap timing or nap duration compared to NC subjects. However, insomnia patients showed higher nap frequency. Frequent napping was associated with poorer subjective sleep quality. Therefore, although napping might not have a negative impact on nocturnal sleep maintenance in NC subjects, it did have an effect on nocturnal sleep in insomnia patients.

Bath Time/Play Time/Nap Time by S. Hughes

Hughes, Susan. Bath Time. Annick Press, 2017.Hughes, Susan. Play Time. Annick Press, 2017.Hughes, Susan. Nap Time. Annick Press, 2017. This is a set of board books on the activities of daily living: sleeping, bathing, and leisure. The concepts are introduced using high resolution stock images of animals paired with words related to the pictures.The “Bath Time” book illustrates the differences and similarities between humans and animals interacting with water. Actions like soaking and splashing are shown, and activities unique to animals like fluttering and licking are depicted. The “Play Time” book shows animals interacting in different environments: trees, snow, water, ice and grass. It also shows animals playing alone and together. The play-words used in this book can be applied to human interaction. The “Nap Time” book’s images show animals sleeping and yawning much like humans would, and shows the natural ways animals sleep that are different from humans (upside down, or in a tree). This book introduces synonymous words for napping like dozing and snoozing, and associative words like snuggling and cuddling.Each book concludes with the question “How do you nap/play/bathe?” which opens up opportunities to talk about these activities, learn word association, and learn about differences between animals and humans. These books bring a new perspective to these activities through the use of animal photos and would be appropriate for prekindergarten children. I would recommend them for public libraries.Highly recommended: 4 out of 4 starsReviewer: Tabatha Plesuk Tabatha Plesuk, is a first year MLIS Student at the University of Alberta (who spends free time teaching dance to children ages three to fourteen) with an enthusiasm for children’s books.

Sleep duration in school-age children with epilepsy: A cross-sectional study

Background: Normal sleep is required for the optimal growth and development of the children. Ineffective or inadequate sleep is common in children with epilepsy. Objectives: The objectives of this study were to study the sleep duration and describe the factors affecting it in school-aged children with epilepsy attending the seizure clinic of a pediatric tertiary care hospital. Materials and Methods: 6–12-year-old children with epilepsy, attending the seizure clinic formed the study subjects. They were assessed for inclusion in the study using INCLEN diagnostic tool for epilepsy (INDT-Epi) to achieve a sample size of 139. Informed written consent was obtained from parents. Background sociodemographic information, seizure type and treatment details, and duration of sleep of the child were collected from the parents. The proportion of children with epilepsy who had sleep problems were expressed as percentage. Results: The mean age of study population was 9.07±2.09 years. The average sleep duration of the study population was 9.41±1.41 h. The mean nap time of the study population was 68.51±33.88 min. No significant association was seen among the factors that determine sleep duration. Conclusion: Children with epilepsy tend to sleep for lesser hours when compared to historic controls of normal school-age children reported in literature.

Effects of Napping During Shift Work on Sleepiness and Performance in Emergency Medical Services Personnel and Similar Shift Workers: A Systematic Review and Meta-Analysis

Background: Scheduled napping during work shifts may be an effective way to mitigate fatigue-related risk. This study aimed to critically review and synthesize existing literature on the impact of scheduled naps on fatigue-related outcomes for EMS personnel and similar shift worker groups. Methods: A systematic literature review was performed of the impact of a scheduled nap during shift work on EMS personnel or similar shift workers. The primary (critical) outcome of interest was EMS personnel safety. Secondary (important) outcomes were patient safety; personnel performance; acute states of fatigue, alertness, and sleepiness; indicators of sleep duration and/or quality; employee retention/turnover; indicators of long-term health; and cost to the system. Meta-analyses were performed to evaluate the impact of napping on a measure of personnel performance (the psychomotor vigilance test [PVT]) and measures of acute fatigue. Results: Of 4,660 unique records identified, 13 experimental studies were determined relevant and summarized. The effect of napping on reaction time measured at the end of shift was small and non-significant (SMD 0.12, 95% CI −0.13 to 0.36; p = 0.34). Napping during work did not change reaction time from the beginning to the end of the shift (SMD −0.01, 95% CI −25.0 to 0.24; p = 0.96). Naps had a moderate, significant effect on sleepiness measured at the end of shift (SMD 0.40, 95% CI 0.09 to 0.72; p = 0.01). The difference in sleepiness from the start to the end of shift was moderate and statistically significant (SMD 0.41, 95% CI 0.09 to 0.72; p = 0.01). Conclusions: Reviewed literature indicated that scheduled naps at work improved performance and decreased fatigue in shift workers. Further research is required to identify the optimal timing and duration of scheduled naps to maximize the beneficial outcomes.

Knowledge, attitude, and practice about infant oral hygiene care among Indian professional working mothers: A questionnaire study

Background: The knowledge of the parents toward the oral hygiene care might get affected by the family structure. Objective: Trend of capsular families in Urban India has led to change in infant oral health practices. Hence, the study was carried out to evaluate the knowledge, attitude, and practice about infant oral care among professional working mothers in Pune city, India. Methods: A 28-item semi-closed, closed-ended questionnaire was administered to 111 professional working mothers in Pune city, India. The data for demographic details, knowledge, attitude, and practice regarding infant oral care were collected with the help of this predesigned self-administered questionnaire from working professional mothers attending outpatient department of Pediatric Hospitals in Pune city. Results: An average, there was limited knowledge among mothers regarding oral health. However, only 13.5% mothers were aware about commercially available tooth wipes, 18% knew when the infant's first dental visit should be scheduled. About 22.5% had practice of bottlefeeding before nap time and 16.2% mothers added sugars/additives in milk while bottlefeeding. Conclusion: All the mothers had overall limited knowledge, positive attitude, and practices were inadequate about infant oral care.

Evertor muscle activity as a predictor for recurrence in idiopathic clubfoot.

Clubfoot is a complex three-dimensional deformity. Although brace compliance after initial correction was previously found to be significantly associated with recurrence in clubfoot, few previous studies have specifically examined evertor muscle function as a factor that contributes to recurrence in children with idiopathic and non-idiopathic clubfoot. The aim of this study was to investigate the relationship among brace compliance, evertor muscle grading, and recurrence rate in pediatric clubfoot patients. Children with idiopathic clubfoot who were treated and followed for a minimum of 2years were included. Patients who used their brace <20-23h a day for the first 3months and then <8-10h per day during sleep and nap times thereafter were classified as group I. Patients who complied fully by using the brace 23h a day for the first 3months and then 8-10h per day during sleep and nap times thereafter were classified as group II. Demographic and clinical data including age, gender, follow-up time, recurrence, evertor muscle grading, types of surgery, brace compliance, severity of initial deformity, age at onset, number of casts required for initial correction, and the need for Achilles tenotomy were collected and analyzed. Seventy-nine children with clubfoot were included. There were 47 males and 32 females, mean age was 3.2years (range 2.1-6.3), and the mean follow-up time was 31.4months. All patients had follow-up of at least 2years. Primary correction was obtained in all children. There was no significant difference in mean age, mean follow-up time, or recurrence rate between groups. There was, however, a statistically significant difference in mean brace time between groups (p=0.002). The recurrence rate was 26.2% in group I and 22.2% in group II. The recurrence rate in group a (Pirani score 0) was 3.9%, group b (Pirani score 0.5) 43.8%, and group c (Pirani score 1) 75% (p<0.001). No significant association was found between severity of the initial deformity, age at the onset of treatment, number of casts required for correction, or reported brace compliance and recurrence or rates of surgery. Only poor or absent evertor muscle activity was found to be statistically significantly associated with risk of recurrence. Good evertor muscle grading was found to be a significant protective factor against recurrence of idiopathic clubfoot. Thus, improvement in muscle balance around the ankle, especially the evertor muscle, should be emphasized to parents after the casting regimen is completed and correction is achieved.

STEENBEEK FOOT ABDUCTION BRACE FOR CLUBFOOT: COST EFFECTIVE BUT IS IT EFFECTIVE? A PROSPECTIVE STUDY

Introduction: Foot Abduction Brace is recommended to prevent recurrence after casting phase in Ponseti method. Various types of braces are described, most current braces with proven efficacy are costly(100-300$) and difficult to acquire especially for the common man in India. Steenbeek brace can be made with locally available materials and is very simple to make and is cost effective(10$). Its efficacy is largely untested.Aim: To evaluate effectiveness of Steenbeek foot abduction brace to maintain correction achieved and to study the reasons for failure and complications associated with the brace.Materials and Methods: In KMC Mangalore and allied hospitals between Jun’2014-Aug’2016 25patients (38feet) who were treated by Ponseti method of cast application were given the Steenbeek foot abduction brace and followed up for a minimum duration of 1 year. The Status of foot was assessed using Pirani score before brace application and at every follow-up. Compliance with the brace protocol was assessed and Compliance defined as brace application for 23 hours/day for the first three months, and nap time brace application for rest of the duration of study.Results: In 36 of 38 feet on the brace the correction was maintained(94.7% effective). In two patients(feet) there was worsening of the Pirani score after brace application and recurrence was seen. The reason for failure was found to be non compliance. The correlation between noncompliance and recurrence was significant(p &lt;0.001) using Fischer Exact Test. Pirani score improved significantly in compliant group with significant worsening noted in noncompliant group. There were no other brace related complications.Conclusions: The significant correlation between noncompliance and recurrence shows that Steenbeek FAB is effective in maintaining correction and can be a cost-effective alternative to the more costly braces, for use in developing countries.

0978 PREVENTION OF SUDDEN UNEXPECTED INFANT DEATH (SUID) DURING SLEEP AT NURSERY SCHOOLS

Sudden Unexpected Infant Death (SUID) is reported to occur in about one of every 6000–7000 live births in Japan. SUID occurs mainly during sleep in infancy and prevention of SUID at this age group is very important not only at home but also at nursery school. The aim of the study was to identify activities currently conducted at each nursery schools to prevent SIDS during the nap, and also the sleeping environment at nursery schools. A questionnaire asking about the activities related to SUID prevention and the sleeping environment was distributed to all the nursery schools in Ehime Prefecture, Japan. One hundred and eighty eight responses were included in the analysis. Percentage of activities currently conducted at each nursery school and sleep environment during the nap were analyzed. Percentage of activities including health checkup in the morning, monitoring by the childminder during the nap time, asking about the health condition of baby from the parents, taking care of baby sleeping position, measurement of body temperature, checking vital signs of sleeping baby, stimulate the baby while taking a nap, monitoring of sleeping baby with video recording, and putting a sensor on baby taking nap were conducted in 95.2%, 94.1%, 93.2%, 92.0%, 87.3%, 45.5%, 10.1%, 1.6% and 0.5% of nursery schools respectively. Sleep environment during nap time was controlled for temperature, light exposure and humidity in more than 80% of the nursery schools. Monitoring of the health condition of the baby and close watch on baby including the body position while napping was made in more than 80% of nursery schools to prevent SUID during nap. Sleep environment was sufficiently controlled in most nursery school.

Comprehensive assessments of long-term sleep habits in epidemiological study: Validity and reliability of sleep factors questionnaire (SFQ) among Chinese women

ObjectiveEpidemiological studies suggested that poor sleep is a potentially novel risk factor for several health outcomes currently; however, there are no validated questionnaires that can systematically measure sleep parameters within these studies. We evaluated the reliability and validity of 17-item sleep factors questionnaire (SFQ), which was developed to comprehensively assess long-term sleep habits for the Jiujiang Breast Cancer Study (JBCS), Jiujiang, China. MethodsThe participants included 100 women aged 18–74years, who were randomly selected from the JBCS project, and completed a SFQ at baseline and again 1year later, and 4 quarterly 30 consecutive days (a total of 120days) sleep diaries over this same year. Reliability was tested by comparing the 2 SFQs; validity by comparing the average measures between the SFQ and the 4 sleep diaries. ResultsValidity analysis showed moderate correlation (γ=0.41) for sleep duration with the adjusted concordance correlation coefficient (CCCadj) of 0.54; the weighted κ statistics indicated an excellent agreement for night/shift work and sleep medication use; fair-to-moderate for sleep quality, light at night (LAN), nighttime sleeping with light on, sleep noise and nap time; slight-to-fair for sleep quality and nighttime wakings frequency. Reliability analysis showed excellent correlation for night/shift work and sleep medication use; fair-to-moderate for LAN, nighttime wakings frequency, insomnia frequency, sleep noise and nap time; but slight-to-fair for insomnia frequency and nighttime sleeping with light on; the CCCadj for sleep duration was 0.61. ConclusionsThe SFQ showed reasonable reliability and validity for sleep assessments in most domains.

Health Management for Medical-surgical Female Nurses Having Night Shift Working

Background: Female nurses are highly susceptive to night shift work. Age, nap times during night shift, physical activity level, and lifestyles strongly associated with fatigue at night shift; however, a comprehensive analysis of these factors including psychological research could not be conducted. Purpose: The purpose of this study is to prove the risk factors for fatigue of medical-surgical female nurses having night shift working based on the data of demographics, lifestyles, subjective symptoms, and performance status from pre night shift to post-holiday. Methods: This cross-sectional study was conducted on 97 Japanese female night shift nurses. The data of age, body mass index, clinical experience years, lifestyles, and nap time during night shift were collected. Total steps, energy expenditure, and subjective symptoms; drowsiness, instability, uneasiness, dullness, and eye strain had been continuously measured and evaluated from pre night shift to post-holiday. Nurses who recovered from fatigue were assigned to a recovery group; other nurses were assigned to a non-recovery group based on improvements in total five subjective symptoms between pre night shift and post-holiday. Results: Age, body mass index, nap time length during night shift, clinical experience years, performance status, and lifestyles were not different between recovery group and non-recovery group. Logistic regression analysis showed that drowsiness and eyestrain are significant risk factor for fatigue at night shift. Adjusted odds ratio (95% confidence interval) for fatigue in medical-surgical female nurse having night shift were 2.04 (1.36-3.01) in drowsiness and 2.03 (1.30-3.18) in eyestrain (P

J-curve relation between daytime nap duration and type 2 diabetes or metabolic syndrome: A dose-response meta-analysis.

Adequate sleep is important for good health, but it is not always easy to achieve because of social factors. Daytime napping is widely prevalent around the world. We performed a meta-analysis to investigate the association between napping (or excessive daytime sleepiness: EDS) and the risk of type 2 diabetes or metabolic syndrome, and to quantify the potential dose-response relation using cubic spline models. Electronic databases were searched for articles published up to 2016, with 288,883 Asian and Western subjects. Pooled analysis revealed that a long nap (≥60 min/day) and EDS were each significantly associated with an increased risk of type 2 diabetes versus no nap or no EDS (odds ratio 1.46 (95% CI 1.23–1.74, p < 0.01) for a long nap and 2.00 (1.58–2.53) for EDS). In contrast, a short nap (<60 min/day) was not associated with diabetes (p = 0.75). Dose-response meta-analysis showed a J-curve relation between nap time and the risk of diabetes or metabolic syndrome, with no effect of napping up to about 40 minutes/day, followed by a sharp increase in risk at longer nap times. In summary, longer napping is associated with an increased risk of metabolic disease. Further studies are needed to confirm the benefit of a short nap.

Treatment of Clubfoot Using the Ponseti Method.

The Ponseti method consists of a specific technique of manipulation of the clubfoot deformity, followed by the application of a plaster cast with the foot in the corrected position. A percutaneous tenotomy of the Achilles tendon is done prior to the final cast to gain complete correction in most patients. Bracing with a foot abduction orthosis is necessary to minimize relapse of the deformity. The method begins with the Ponseti manipulation and consists of the following steps: (1) Identify the head of the talus by palpation. (2) Supinate the forefoot to eliminate the cavus deformity and create a normal-appearing arch. (3) Abduct the forefoot with the vector of force parallel to the sole of the foot while using the lateral head of the talus as the fulcrum and maintaining the reduction of the cavus deformity. (4) This manipulation is followed by the application of an above-the-knee cast with the foot in the corrected position. (5) The manipulation and casting steps are repeated every 5 to 7 days until the foot is abducted approximately 50° from the frontal plane of the tibia. (6) In most patients (60% to >90%), a percutaneous tenotomy of the Achilles tendon is necessary to correct the residual ankle equinus after gaining full abduction of the foot with the manipulations. (7) The final cast is applied and worn for three weeks. (8) After removal of the final cast, the patient is managed with bracing with a foot abduction orthosis for 23 hours per day for 3 months. Bracing at night and during nap time is recommended until the child is 4 to 5 years old. The cavus deformity is eliminated after the application of 2 or 3 casts by the simple positioning maneuver. Abduction of the forefoot in the plane of the sole of the foot while using the head of the talus as the fulcrum results in the correction of the midfoot adduction deformity simultaneously with the hindfoot varus and the subtalar component of the equinus deformity. After full abduction is obtained, the cavus, adduction, and subtalar varus and equinus deformities are all completely corrected. The only residual deformity is the ankle equinus. Most feet require a percutaneous tenotomy to fully correct the ankle component of the equinus. The tenotomy can be performed as an outpatient procedure under local anesthetic without the need for sedation. If the foot can be dorsiflexed to >15° (without midfoot breach), a tenotomy is unnecessary. This manipulation allows complete correction of almost all idiopathic clubfeet in 4 to 7 sessions. Long-term follow-up (mean, 34 years; range, 25 to 42 years) has shown that clubfeet treated with the Ponseti method function as well as normal feet with respect to pain and level of activity.

Medical Decisions of Pediatric Residents Turn Riskier after a 24-Hour Call with No Sleep.

Despite a gradual reduction in the workload during residency, 24-hour calls are still an integral part of most training programs. While sleep deprivation increases the risk propensity, the impact on medical risk taking has not been studied. This study aimed to assess the clinical decision making and psychomotor performance of pediatric residents following a limited nap time during a 24-hour call. A neurocognitive battery (IntegNeuro) and a medical decision questionnaire were completed by 44 pediatric residents at 2 time points: after a 24-hour call and following 3 nights with no calls (sleep ≥5 hours). To monitor sleep, residents wore actigraphs and completed sleep logs. Nap time during the shift was <1 hour in 14 cases (32%), 1 to 2 hours in 16 cases (35%), and 2 to 3 hours in 14 cases (32%). Residents who napped less than 1 hour chose the riskier medical option in 50% of cases compared with 36% when answering the same questionnaire after 3 nights with no calls (P = 0.002). This effect was not found in residents who napped 1 to 2 hours (no change in risk taking) or 2 to 3 hours (4% decreased risk taking) (difference between groups, P = 0.001). Risk-taking tendency inversely correlated with sustained attention scores (Pearson = -0.433, P = 0.003). Sustained attention was the neurocognitive domain most affected by sleep deprivation (effect size = 0.29, P = 0.025). This study suggests that residents napping less than an hour during a night shift are prone to riskier clinical decisions. Hence, enabling residents to nap at least 1 hour during shifts is recommended.

Daytime nap controls toddlers' nighttime sleep.

Previous studies have demonstrated that afternoon naps can have a negative effect on subsequent nighttime sleep in children. These studies have mainly been based on sleep questionnaires completed by parents. To investigate the effect of napping on such aspects of sleep quality, we performed a study in which child activity and sleep levels were recorded using actigraphy. The parents were asked to attach actigraphy units to their child’s waist by an adjustable elastic belt and complete a sleep diary for 7 consecutive days. 50 healthy young toddlers of approximately 1.5 years of age were recruited. There was a significant negative correlation between nap duration and both nighttime sleep duration and sleep onset time, suggesting that long nap sleep induces short nighttime sleep duration and late sleep onset time. We also found a significant negative correlation between nap timing and nighttime sleep duration and also a significant positive correlation between nap timing and sleep onset time, suggesting that naps in the late afternoon also lead to short nighttime sleep duration and late sleep onset. Our findings suggest that duration-controlled naps starting early in the afternoon can induce a longer nighttime sleep in full-term infants of approximately 1.5 years of age.

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Development of the Sedentary Behavior Questionnaire for the Elderly

This study aimed to develop a reliable and valid questionnaire for measuring the time spent in different types of sedentary behaviors among elderly in their later life. Eighty community-dwelling older adults aged 65 years or above were completed the questionnaire twice over a one-week period, and wore a tri-axial accelerometer during this period. The test-retest reliability over a one-week period was evaluated by paired-sample t-tests and Spearmen’s correlation. Concurrent validity was first examined using Spearman’s correlation by self-reported total sedentary time and accelerometer-assessed sedentary time. Then, the Bland-Altman Plot was utilized to compare the agreement between the self-reported measure and the objective measure. Based on nine types of sedentary behaviors, the mean self-reported total sedentary time was 7.29 ± 3.60 hours/day without napping time (0.64 hours/day). Regarding test-retest reliability, except reading, there were no significant differences in the self-reported total sedentary time and each type of sedentary time between pre- and post-test. Spearmen’s correlation analyses showed that test-retest reliability was satisfactory for taking a nap, computer/internet use, working or volunteering and reading; marginally acceptable for watching TV, eating and hobbies; and poor for chatting, driving/sitting in a car, and others. Total sedentary time (including napping time) on an average day (sum of ten activities) had adequate test-retest reliability. Self-reported total sedentary time was significantly correlated with accelerometer-derived sedentary time, revealing that the concurrent validity was adequate. The Bland-Altman Plot indicated self-reported total sedentary time on average underestimated accelerometer-derived sedentary time by -0.59 hours/day. However, the mean self-reported total sedentary time was not significantly different from mean objective sedentary time. Overall, this study demonstrated the preliminary evidence for the reliability and validity of questionnaire for assessing the sedentary behaviors among Taiwanese older adults.

Mandatory Nap Times and Group Napping Patterns in Child Care: An Observational Study

Policy provision for naps is typical in child care settings, but there is variability in the practices employed. One practice that might modify children’s early sleep patterns is the allocation of a mandatory nap time in which all children are required to lie on their beds without alternate activity permitted. There is currently limited evidence of the effects of such practices on children’s napping patterns. This study examined the association between duration of mandatory nap times and group-level napping patterns in child care settings. Observations were undertaken in a community sample of 113 preschool rooms with a scheduled nap time (N = 2,114 children). Results showed that 83.5% of child care settings implemented a mandatory nap time (range = 15–145 min) while 14.2% provided alternate activities for children throughout the nap time period. Overall, 31% of children napped during nap times. Compared to rooms with ≤ 30 min of mandatory nap time, rooms with 31–60 min and > 60 min of mandatory nap time had a two-and-a-half and fourfold increase, respectively, in the proportion of children napping. Nap onset latency did not significantly differ across groups. Among preschool children, exposure to longer mandatory nap times in child care may increase incidence of napping.

Daytime Napping and the Risk of Cardiovascular Disease and All-Cause Mortality: A Prospective Study and Dose-Response Meta-Analysis.

To summarize evidence about the association between daytime napping and the risk of cardiovascular disease and all-cause mortality, and to quantify the potential dose-response relation. Meta-analysis of prospective cohort studies. Electronic databases were searched for articles published up to December 2014 using the terms nap, cardiovascular disease, and all-cause mortality. We selected well-adjusted prospective cohort studies reporting risk estimates for cardiovascular disease and all-cause mortality related to napping. Eleven prospective cohort studies were identified with 151,588 participants (1,625,012 person-years) and a mean follow-up period of 11 years (60% women, 5,276 cardiovascular events, and 18,966 all-cause deaths). Pooled analysis showed that a long daytime nap (≥ 60 min/day) was associated with a higher risk of cardiovascular disease (rate ratio [RR]: 1.82 [1.22-2.71], P = 0.003, I(2) = 37%) compared with not napping. All-cause mortality was associated with napping for ≥ 60 min/day (RR: 1.27 [1.11-1.45], P < 0.001, I(2) = 0%) compared with not napping. In contrast, napping for < 60 min/day was not associated with cardiovascular disease (P = 0.98) or all-cause mortality (P = 0.08). Meta-analysis demonstrated a significant J-curve dose-response relation between nap time and cardiovascular disease (P for nonlinearity = 0.01). The RR initially decreased from 0 to 30 min/day. Then it increased slightly until about 45 min/day, followed by a sharp increase at longer nap times. There was also a positive linear relation between nap time and all-cause mortality (P for non-linearity = 0.97). Nap time and cardiovascular disease may be associated via a J-curve relation. Further studies are needed to confirm the efficacy of a short nap.

Do night naps impact driving performance and daytime recovery sleep?

Short, nighttime naps are used as a fatigue countermeasure in night shift work, and may offer protective benefits on the morning commute. However, there is a concern that nighttime napping may impact upon the quality of daytime sleep. The aim of the current project was to investigate the influence of short nighttime naps (<30min) on simulated driving performance and subsequent daytime recovery sleep. Thirty-one healthy subjects (aged 21–35 y; 18 females) participated in a 3-day laboratory study. After a 9-h baseline sleep opportunity (22:00h–07:00h), subjects were kept awake the following night with random assignment to: a 10-min nap ending at 04:00h plus a 10-min nap at 07:00h; a 30-min nap ending at 04:00h; or a no-nap control. A 40-min driving simulator task was administered at 07:00h and 18:30h post-recovery sleep. All conditions had a 6-h daytime recovery sleep opportunity (10:00h–16:00h) the next day. All sleep periods were recorded polysomnographically. Compared to control, the napping conditions did not significantly impact upon simulated driving lane variability, percentage of time in a safe zone, or time to first crash on morning or evening drives (p>0.05). Short nighttime naps did not significantly affect daytime recovery total sleep time (p>0.05). Slow wave sleep (SWS) obtained during the 30-min nighttime nap resulted in a significant reduction in SWS during subsequent daytime recovery sleep (p<0.05), such that the total amount of SWS in 24-h was preserved. Therefore, short naps did not protect against performance decrements during a simulated morning commute, but they also did not adversely affect daytime recovery sleep following a night shift. Further investigation is needed to examine the optimal timing, length or combination of naps for reducing performance decrements on the morning commute, whilst still preserving daytime sleep quality.

Job demands and resting and napping opportunities for nurses during night shifts: impact on sleepiness and self-evaluated quality of healthcare.

The aim of this field study is to describe night shift resting and napping strategies and to examine their beneficial effects on sleepiness and quality of work. The study was carried out with 16 nurses working in an intensive care unit. Data collected during 20 night shifts were related to job demands (systematic observations), to the duration and timing of rests and naps taken by nurses (systematic observations, sleep diaries), to sleepiness (Karolinska Sleepiness Scale), and to quality of work scores (visual analog scale). The results showed that the number of rests and naps depended on the job demands. Resting and napping lowered the levels of sleepiness at the end of the shift. There was no direct relationship between sleepiness and the quality of work score. Discussions about the choice of indicators for the quality of work are necessary. Suggestions for implementing regulations for prescribed napping during night shifts are presented.