***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: & NA ; Cross‐sectional research in clinical sample s , as well as experimental studies in healthy adults , suggests that the experiences of pain and sleep are bi‐directionally connected . However , whether sleep and pain experiences are prospect ively linked to one another on a day‐to‐day basis in the general population has not previously been reported . This study utilizes data from a naturalistic , micro‐longitudinal , telephone study using a representative national sample of 971 adults . Participants underwent daily assessment of hours slept and the reported frequency of pain symptoms over the course of one week . Sleep duration on most nights ( 78.0 % ) was between 6 and 9 h , and on average , daily pain was reported with mild frequency . Results suggested that hours of reported sleep on the previous night was a highly significant predictor of the current day ’s pain frequency ( Z = −7.9 , p < .0001 , in the structural equation model ) ; obtaining either less than 6 or more than 9 h of sleep was associated with greater next‐day pain . In addition , pain prospect ively predicted sleep duration , though the magnitude of the association in this direction was somewhat less strong ( Z = −3.1 , p = .002 , in the structural equation model ) . Collectively , these findings indicate that night‐to‐night changes in sleep affect pain report , illuminating the importance of considering sleep when assessing and treating pain STUDY OBJECTIVES Pain is a leading cause of sleep disturbances in medical illness . Providing effective analgesia is considered an important intervention to reduce these sleep disturbances . Opioids remain the treatment of choice to relieve postoperative pain in hospitalized patients . However , their effects on sleep in pain patients or normal subjects remain unclear , as previous studies have been conducted mainly with former opioid addicts . The purpose of this investigation was to evaluate and describe the effects of acute clinical doses of morphine on sleep in healthy pain-free subjects . DESIGN Subjects were r and omly assigned to untreated ( baseline ) , morphine ( intravenous injections of 0.1 [ DOSAGE ERROR CORRECTED ] mg/kg ) , and placebo ( intravenous injections of 0.9 % NaCI ) conditions . SETTING Sleep laboratory . PARTICIPANTS Seven healthy pain-free , nonaddicts ( 5 women , 2 men ; mean age = 25 + /- 1.6 years ) . MEASUREMENTS AND RESULTS St and ard polysomnographic sleep and respiratory variables were measured during 3 experimental conditions . The treatment effect was analyzed with a Latin square cross-over design followed , when appropriate , by Tukey contrasts . Morphine altered sleep architecture by reducing slow-wave sleep ( non-rapid eye movement stages 3 - 4 ) and rapid eye movement sleep , and by increasing non-rapid eye movement stage 2 sleep . Results did not reveal any statistical differences for other sleep and respiratory variables . CONCLUSIONS Similar to earlier findings in animals , nondependent opiate addicts , and postoperative patients , morphine was found to reduce duration of slow-wave sleep . Unlike previous reports , however , its acute administration produced a moderate reduction in rapid eye movement sleep and did not increase correlates of arousal ( ie , awakenings , electroencephalogram arousals , wake after sleep onset ) . Future studies should correlate these findings in patients with pain and evaluate whether optimal pain relief with opioid therapy can improve sleep disturbances in pain patients Most patients with asthma waken with nocturnal asthma from time to time . To assess morbidity in patients with nocturnal asthma nocturnal sleep quality , daytime sleepiness , and daytime cognitive performance were measured prospect ively in 12 patients with nocturnal asthma ( median age 43 years ) and 12 age and intellect matched normal subjects . The median ( range ) percentage overnight fall in peak expiratory flow rate ( PEF ) was 22 ( 15 to 50 ) in the patients with nocturnal asthma and 4 ( -4 to 7 ) in the normal subjects . The patients with asthma had poorer average scores for subjective sleep quality than the normal subjects ( median paired difference 1.1 ( 95 % confidence limits 0.1 , 2.3 ) ) . Objective overnight sleep quality was also worse in the asthmatic patients , who spent more time awake at night ( median difference 51 ( 95 % CL 8.1 , 74 ) minutes ) , had a longer sleep onset latency ( 12 ( 10 , 30 ) minutes ) , and tended to have less stage 4 ( deep ) sleep ( -33 ( -58 , 4 ) minutes ) . Daytime cognitive performance was worse in the patients with nocturnal asthma , who took a longer time to complete the trail making tests ( median difference 62 ( 22 , 75 ) seconds ) and achieved a lower score on the paced serial addition tests ( -10 ( -24 , -3 ) ) . Mean daytime sleep latency did not differ significantly between the two groups ( 2 ( -3 , 7 ) minutes ) . It is concluded that hospital out patients with stable nocturnal asthma have impaired sleep quality and daytime cognitive performance even when having their usual maintenance asthma treatment STUDY OBJECTIVES To study the nature of sleep disturbance in depressed and nondepressed patients with chronic low back pain ( CLBP ) . DESIGN A controlled , consecutive 4-night polysomnographic study . PATIENTS Participants were screened ( psychologic , psychiatric , and physical ) to determine their study group , and 21 participants ( CLBP : 4 depressed , 6 nondepressed and 11 controls ) were studied . MEASUREMENTS AND RESULTS On all nights ,  st and ard polysomnographic sleep measures  as well as  midline occipital and frontal electroencephalography and respiration  were recorded on a Grass Model 7 polygraph .  Pain , sleep quality , and depression were also measured . Participants with CLBP reported significant levels of pain and sleep disturbance as compared to controls , but all groups had equivalent amounts of sleep and comparable sleep architecture . The electroencephalographic power spectral analyses revealed significant differences , with controls having more sigma across sites , more low beta activity occipitally and frontally than nondepressed patients with CLBP , and more occipital sigma and less high beta activity than depressed participants . Between pain subgroups , the depressed participants showed more occipital delta , more occipital and central alpha , and more high beta activity across all sites than did the nondepressed participants . CONCLUSIONS Lower sigma power in participants with CLBP suggests less-effective sensorimotor gating that may contribute to poor sleep quality . Pain subgroup differences underscore the need to consider the influence of depression in the evaluation of sleep in clinical population s. This study controlled for many factors other than pain that may contribute to the sleep complaints in this population . Consequently , the absence of signs of major sleep disturbance must not be interpreted as evidence of a lack of a true sleep problem in CLBP but more likely reflects control of these factors as well as the difficulty in measuring sleep quality Abstract . When measuring treatment effect in chronic low back pain with multi-item outcome instruments , it is necessary , both for clinical decision-making and research purpose s , to underst and the clinical importance of the outcome scores . The aims of the present study were three-fold . Firstly , it aim ed to estimate the minimal clinical ly important difference of three multi-item outcome instruments ( the Oswestry Disability Index , the General Function Score and the Zung Depression Scale )  and of the  visual analogue scale ( VAS ) of back pain .  Secondly , it aim ed to estimate the error of measurement of these instruments ; and its third aim was to describe the clinical meaning of score change . The study population consisted of 289 patients treated surgically or non-surgically in a r and omised controlled trial . The minimal clinical ly important difference was estimated with patient global assessment as the external criterion . It was compared with the st and ard error of measurement of the instruments . The individual items of the instruments were compared for score changes related to improvement and deterioration . The st and ard error of measurement of the Oswestry Disability Index , the General Function Score and the Zung Depression Scale was 4 , 6 and 3 units , respectively . The 95 % tolerance interval was 10 , 16 and 8 units , respectively . The minimal clinical ly important difference was 10 , 12 and 8–9 units , respectively , thus not significantly exceeding the tolerance interval . The minimal clinical ly important difference of VAS back pain was 18–19 units , well exceeding the 95 % tolerance interval , which was 15 units . Improvement after treatment for chronic low back pain tends to occur to a greater extent in sleep disturbance , ability to do usual things and psychological irritability , but to a lesser extent in the ability to sit , st and and lift . We conclude that the VAS of back pain is responsive enough to detect the minimal clinical ly important difference , whereas the smallest acceptable score changes of the Oswestry Disability Index , the General Function Score and the Zung Depression Scale may require an increase to exceed the 95 % tolerance interval when used for clinical decision making and for power calculation . Despite improvement after treatment , the ability to sit , st and and lift , remain notable problems The aim of this study was to compare the effects of total sleep deprivation ( TSD ) , rapid eye movement ( REM ) sleep and slow wave sleep ( SWS ) interruption and sleep recovery on mechanical and thermal pain sensitivity in healthy adults . Nine healthy male volunteers ( age 26 - -43 years ) were r and omly assigned in this double blind and crossover study to undergo either REM sleep or SWS interruption . Periods of 6 consecutive laboratory nights separated by at least 2 weeks were design ed as follows : N1 Adaptation night ; N2 Baseline night ; N3 Total sleep deprivation ( 40 h ) ; N4 and N5 SWS or REM sleep interruption ; N6 Recovery . Sleep was recorded and scored using st and ard methods . Tolerance thresholds to mechanical and thermal pain were assessed using an electronic pressure dolorimeter and a thermode operating on a Peltier principle . Relative to baseline levels , TSD decreased significantly mechanical pain thresholds ( -8 % ) . Both REM sleep and SWS interruption tended to decrease mechanical pain thresholds . Recovery sleep , after SWS interruption produced a significant increase in mechanical pain thresholds ( + 15 % ) . Recovery sleep after REM sleep interruption did not significantly increase mechanical pain thresholds . No significant differences in thermal pain thresholds were detected between and within periods . In conclusion this experimental study in healthy adult volunteers has demonstrated an hyperalgesic effect related to 40 h TSD and an analgesic effect related to SWS recovery . The analgesic effect of SWS recovery is apparently greater than the analgesia induced by level I ( World Health Organization ) analgesic compounds in mechanical pain experiments in healthy volunteers Marin R , Cyhan T , Miklos W : Sleep disturbance in patients with chronic low back pain . Am J Phys Med Rehabil 2006;85:430–435 . Objective : To document the relationship between sleep disturbance and chronic low back pain in patients referred to a physical medicine and rehabilitation clinic . Design : This is a prospect i ve cross-sectional survey of 268 patients 18 yrs or older being evaluated for low back pain of greater than 6 months at a tertiary medical center . The survey consisted of a 43-item composite form that contained the Short-Form McGill Pain Question naire ( SF-MPQ ) ; the  Pittsburgh Sleep Quality Index ( PSQI ) ; a pain visual analog scale ( VAS ) ; and questions regarding bed type , sleep position , and patients ' sleep description .  Results : There was a significant relationship between pain and sleep ( P < 0.0005 ) with a 55 % increase in the proportion of subjects reporting restless/light sleep after pain onset . There was no corresponding increase in sleep medication use . There was a significant direct correlation between SF-MPQ and PSQI ( r = 0.44 , P < 0.0005 ) ; between PSQI and VAS ( r = 0.41 , P < 0.0005 ) ; and between overall quality of sleep and VAS ( r = 0.31 , P < 0.0005 ) . Finally , PSQI scores were the worst in subjects sleeping on an orthopedic mattress ( P = 0.001 ) . Conclusions : Chronic low back pain significantly affects quality of sleep . Sleep problems should be addressed as an integral part of the pain management plan & NA ; Sleep disturbances are frequently reported in victims following burn injuries . This prospect i ve study was design ed to assess sleep quality and to examine its daily relationship to pain intensity within the first week of hospitalization . Twenty‐eight non‐ventilated patients were interviewed during 5 consecutive mornings ( number of observations=140 ) to collect information about perceived quality of sleep ( visual analogue scale , number of hours , number of awakenings , presence of nightmares ) . Pain intensity was assessed at rest ( nighttime , morning , during the day ) and following therapeutic procedures using a 0–10 numeric scale . Seventy‐five percent of patients  reported sleep disturbances at some point during the study although , in most patients , sleep quality was not consistently poor . Pooled cross‐section regression analyses showed significant temporal relationships between quality of sleep and pain intensity such that a night of poor sleep was followed by a significantly more painful day . Pain during the day was not found to be a significant predictor of poor sleep on the following night . These results support previous findings that perceived quality of sleep following burn injury is poor . Moreover , they show a daily relationship between quality of sleep and acute burn pain in which poor sleep is linked to higher pain intensity during the day Men from the general population and male professional lorry and bus drivers were surveyed with regard to sleep habits and motor vehicle and other types of accidents . A r and om sample of 4000 men in the general population of Dalarna County in mid-Sweden were mailed a question naire and served as referents . A total of 1389 male professional lorry and bus drivers from this county responded to the same question naire . A total of 161 of the drivers also underwent a sleep study in their homes . The proportion of total accidents was higher among the professional drivers as compared with the males in the population , P=0.03 . Reports on traffic accidents were the same in both groups , but the professional drivers reported more acc 
    Output:
    
Consistent evidence found that CLBP was associated with greater sleep disturbance ; reduced sleep duration and sleep quality ; increased time taken to fall asleep ; poor day-time function ; and greater sleep dissatisfaction and distress .
Inconsistent evidence was found that sleep efficiency and activity were adversely associated with CLBP .
DISCUSSION many dimensions of sleep are adversely associated with CLBP .