***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: This study surveyed Certified Registered Nurse Anesthetist ( CRNA ) members of the American Association of Nurse Anesthetists ( AANA ) on their frequency of call-shift fatigue , fatigue symptoms , medical errors associated with fatigue , and use of fatigue counter measures and avoidance strategies . A secondary aim was to identify predictors of call-shift fatigue . An invitation to complete an anonymous electronic survey was sent to 2,500 r and omly selected AANA members . Data were collected on CRNAs ' fatigue experience ,  call-shift length and frequency , errors in patient care , and use of fatigue counter measures and avoidance strategies . Analysis included descriptive and inferential statistics . Logistic regression was used to identify predictors of call-shift fatigue . Of 325 CRNAs who provided data , 82 % reported experiencing call-shift fatigue , 87 % used  fatigue counter measures , 77 % used fatigue-avoidance strategies , and 28 % reported committing a medical error because of fatigue . Predictors included hours to recovery from a call shift ( odds ratio [ OR ] = 1.08 , 95 % confidence interval [ CI ] = 1.04 - 1.12 ) , working 5 to 6 calls per month ( OR = 3.78 , CI = 1.17 - 12.23 ) , working 7 or more calls per month ( OR = 4.87 , CI = 1.93 - 12.33 ) , use of fatigue counter measures ( OR = 5.44 , CI = 2.15 - 13.77 ) , and fatigue symptoms ( OR = 2.19 , CI = 1.03 - 4.67 ) . Call-shift fatigue is a common problem among CRNAs and is associated with medical errors and negative health consequences Study Objectives While short and poor quality sleep among training physicians has long been recognized as problematic , the longitudinal relationships among sleep , work hours , mood , and work performance are not well understood . Here , we prospect ively characterize the risk of depression and medical errors based on preinternship sleep disturbance , internship-related sleep duration , and duty hours . Methods  Survey data from 1215 nondepressed interns were collected at preinternship baseline , then 3 and 6 months into internship . We examined how preinternship sleep quality and internship sleep and work hours affected risk of depression at 3 months , per the Patient Health Question naire 9 . We then examined the impact of sleep loss and work hours on depression persistence from 3 to 6 months . Finally , we compared self-reported errors among interns based on nightly sleep duration ( ≤6 hr vs. > 6 hr ) , weekly work hours ( < 70 hr vs. ≥70 hr ) , and depression ( non- vs. acutely vs. chronically depressed ) . Results Poorly sleeping trainees obtained less sleep and were at elevated risk of depression in the first months of internship . Short sleep ( ≤6 hr nightly ) during internship mediated the relationship between sleep disturbance and depression risk , and sleep loss led to a chronic course for depression . Depression rates were highest among interns with both sleep disturbance and short sleep . Elevated medical error rates were reported by physicians sleeping ≤6 hr per night , working ≥ 70 weekly hours , and who were acutely or chronically depressed . Conclusions Sleep disturbance and internship-enforced short sleep increase risk of depression development and chronicity and medical errors . Interventions targeting sleep problems prior to and during residency hold promise for curbing depression rates and improving patient care BACKGROUND Sleep deprivation has been associated with an increased incidence of medical errors and can jeopardise patients ' safety during medical crisis management . The aim of the study was to assess the effect of sleep deprivation on the management of simulated anaesthesia crisis by residents in anaesthesiology . METHODS A r and omised , comparative , monocentric crossover study involving 48 residents in anaesthesia was performed on a high fidelity patient simulator . Each resident was evaluated in a sleep-deprived state ( deprived group , after a night shift duty ) and control state ( control group , after a night of sleep ) . Performance was assessed through points obtained during crisis scenario 1 ( oesophageal intubation followed by anaphylactic shock ) and scenario 2 ( anaesthesia-related bronchospasm followed by ventricular tachycardia ) . Sleep periods were recorded by actigraphy . Two independent observers assessed the performances . The primary endpoint of the study was the score obtained for each scenario . RESULTS Resident 's crisis management performance is associated with sleep deprivation ( scenario 1 : control=39 [ 33 - 42 ] points vs. deprived=26 [ 19 - 40 ] points , P=0.02 ; scenario 2 : control=21 [ 17 - 24 ] vs. deprived=14 [ 12 - 19 ] , P=0.01 ) . The main errors observed were : error in drug administration and dose , delay in identification of hypotension , and missing communication with the surgical team about situation . CONCLUSIONS The present study showed that sleep deprivation is associated with impairment of performance to manage crisis situations by residents in anaesthesia CONTEXT Better hospital nurse staffing , more educated nurses , and improved nurse work environments have been shown to be associated with lower hospital mortality  . Little is known about whether and under what conditions each type of investment works better to improve outcomes . OBJECTIVE To determine the conditions under which the impact of  hospital nurse staffing , nurse education , and work environment are associated with patient outcomes . DESIGN , SETTING , AND PARTICIPANTS Outcomes of 665 hospitals in 4 large states were studied through linked data from hospital discharge abstract s for 1,262,120 general , orthopedic , and vascular surgery patients , a r and om sample of 39,038 hospital staff nurses , and American Hospital Association data . MAIN OUTCOME MEASURES A 30-day inpatient mortality and failure-to-rescue . RESULTS The effect of decreasing workloads by 1 patient/nurse on deaths and failure-to-rescue is virtually nil in hospitals with poor work environments , but decreases the odds on both deaths and failures in hospitals with average environments by 4 % , and in hospitals with the best environments by 9 % and 10 % , respectively . The effect of 10 % more Bachelors of Science in Nursing Degree nurses decreases the odds on both outcomes in all hospitals , regardless of their work environment , by roughly 4 % . CONCLUSIONS Although the positive effect of increasing percentages of Bachelors of Science in Nursing Degree nurses is consistent across all hospitals , lowering the patient-to-nurse ratios markedly improves patient outcomes in hospitals with good work environments , slightly improves them in hospitals with average environments , and has no effect in hospitals with poor environments Background : Shorter resident duty periods are increasingly m and ated to improve patient safety and physician well-being . However , increases in continuity-related errors may counteract the purported benefits of reducing fatigue . We evaluated the effects of  3 resident schedules in the intensive care unit ( ICU ) on patient safety , resident well-being and continuity of care . Methods : Residents in 2 university-affiliated ICUs were r and omly assigned ( in 2-month rotation-blocks from January to June 2009 ) to in-house overnight schedules of 24 , 16 or 12 hours . The primary patient outcome was adverse events . The primary resident outcome was sleepiness , measured by the 7-point Stanford Sleepiness Scale . Secondary outcomes were patient deaths , preventable adverse events , and residents ’ physical symptoms and burnout . Continuity of care and perceptions of ICU staff were also assessed . Results : We evaluated 47 ( 96 % ) of 49 residents , all 971 admissions , 5894 patient-days and 452 staff surveys . We found no effect of schedule ( 24- , 16- or 12-h shifts ) on adverse events ( 81.3 , 76.3 and 78.2 events per 1000 patient-days , respectively ; p = 0.7 ) or on residents ’ sleepiness in the daytime ( mean rating 2.33 , 2.61 and 2.30 , respectively ; p = 0.3 ) or at night ( mean rating 3.06 , 2.73 and 2.42 , respectively ; p = 0.2 ) . Seven of 8 preventable adverse events occurred with the 12-hour schedule ( p = 0.1 ) . Mortality rates were similar for the 3 schedules . Residents ’ somatic symptoms were more severe and more frequent with the 24-hour schedule ( p = 0.04 ) ; however , burnout was similar across the groups . ICU staff rated residents ’ knowledge and decision-making worst with the 16-hour schedule . Interpretation : Our findings do not support the purported advantages of shorter duty schedules . They also highlight the trade-offs between residents ’ symptoms and multiple secondary measures of patient safety . Further delineation of this emerging signal is required before widespread system change . Trial registration : Clinical Trials.gov , no. NCT00679809 BACKGROUND To minimize the occurrence of adverse events among patients , critical care nurses must be alert to subtle changes in patients ' conditions , perform accurate clinical assessment s , and respond expediently . However , little is known about the effects of the nurses ' work hours on vigilance and patients ' safety . OBJECTIVES To describe the work patterns of critical care nurses , determine if an association exists between the occurrence of errors and the hours worked by the nurses , and explore whether these work hours have adverse effects on the nurses ' vigilance . METHODS Data were obtained from a r and om sample of critical care nurses in the United States . Nurses eligible for the study were mailed two 14-day logbooks  to fill out . Information collected included the hours worked , the time of day worked , overtime hours , days off , and sleep-wake patterns . On days worked , the respondents completed all work-related questions and questions about difficulties in remaining awake while on duty . Space was provided for descriptions of any errors or near errors that might have occurred . On days off , the nurses completed only those questions about sleep-wake patterns , mood , and caffeine intake . RESULTS The 502 respondents consistently worked longer than scheduled and for extended periods . Longer work duration increased the risk of errors and near errors and decreased nurses ' vigilance . CONCLUSIONS The findings support the Institute of Medicine recommendations to minimize the use of 12-hour shifts and to limit nurses ' work hours to no more than 12 consecutive hours during a 24-hour period RATIONALE Around-the-clock intensivist presence in intensive care units ( ICUs ) has been promoted as necessary to optimize outcomes . Little data have addressed how it affects the multiple stakeholders in such care . OBJECTIVES To assess effects of around-the-clock intensivist presence on intensivists , patients , families , housestaff , and nurses . METHODS This 32-week , crossover pilot trial of two intensivist staffing models , performed in two Canadian ICUs , alternated 8-week blocks of two staffing models : the st and ard model , where one intensivist worked for 7 days , taking night call from home ; and the shift work model , where one intensivist worked 7 day shifts , while other intensivists remained in the ICU at night . MEASUREMENTS AND MAIN RESULTS Surveys scaled from 0 - 100 points assessed outcomes for 24 intensivists ( primary outcome : burnout ) ; 119 families ( satisfaction ) ; 74 nurses  ( satisfaction with collaboration and communications , role conflict ) ; and 34 housestaff ( autonomy , supervision , and learning opportunities ) . Outcomes for 501 patients included mortality , length of stay , and re source use . Intensivists doing shift work experienced less burnout ( -6.9 points ; P = 0.04 ) . Adjusted hospital mortality ( odds ratio , 1.22 ; P = 0.44 ) , ICU length of stay ( -6 h ; P = 0.46 ) , and family satisfaction ( 0.9 points ; P = 0.79 ) did not differ between staffing models . Under shift work staffing , nurses reported more role conflict ( 9 points ; P < 0.001 ) , whereas nighttime housestaff reported less autonomy , more supervision , but no difference in learning opportunities . CONCLUSIONS Shiftwork staffing was better for intensivists and most were receptive once they had experienced it . Although there were no evident negative outcomes for patients or families , further evaluation is needed to clarify how around-the-clock intensivist staffing influences the various stakeholders in ICU care , given power considerations in this study . Clinical trial registered with www . clinical trials.gov ( NCT 01146691 ) Purpose . To secure data from residents regarding residency work hours and correlates . Method . A national , r and om sample of postgraduate year 1 ( PGY1 ) and year 2 ( PGY2 ) residents in the 1998 - 1999 training year was identified using the American Medical Association ’s Graduate Medical Education data base . Residents completed a five-page survey with 44 questions and 144 separate data elements relating to their residency experience . Results . Completed surveys were received from 3,604 of 5,616 ( 64.2 % ) residents contacted . PGY1 residents reported working an average of 83 hours a week versus 76.2 hours for PGY2 residents ( p < .0001 ) . Total work hours were significantly correlated with reported stress and hours of sleep per week . Residents averaging more than 80 work hours per week were more likely to be involved in a personal accident or injury , a serious conflict with other staff members , and making a significant medical error . Cluster analysis revealed four different types of residency experience : 
    Output:
    
Studies that find that working time is detrimental to employee health , generally also find detrimental results for patient safety .
This is particularly shown through increases in errors by health personnel .
When controlling for employee health , the relationship between  working time arrangements and patient safety is reduced , but still significant .
Conclusions Results suggest that employee health partially ( but not completely ) mediates the relationship between working time arrangements and patient safety .
However , there is a lack of studies directly investigating employee health as a mediator between working time arrangements and patient safety .