The quantity of nursing care on wards working 8- and 12-hour shifts

Because they're worth it? A discussion paper on the value of 12-h shifts for hospital nursing

The organisation of the 24-h day for hospital nurses in two 12-h shifts has been introduced with value propositions of reduced staffing costs, better quality of care, more efficient work organisation, and increased nurse recruitment and retention. While existing reviews consider the impact of 12-h shifts on nurses' wellbeing and performance, this discussion paper aims to specifically shed light on whether the current evidence supports the value propositions around 12-h shifts. We found little evidence of the value propositions being realised. Staffing costs are not reduced with 12-h shifts, and outcomes related to productivity and efficiency, including sickness absence and missed nursing care are negatively affected. Nurses working 12-h shifts do not perform more safely than their counterparts working shorter shifts, with evidence pointing to a likely negative effect on safe care due to increased fatigue and sleepiness. In addition, nurses working 12-h shifts may have access to fewer educational opportunities than nurses working shorter shifts. Despite some nurses preferring 12-h shifts, the literature does not indicate that this shift pattern leads to increased recruitment, with studies reporting that nurses working long shifts are more likely to express intention to leave their job. In conclusion, there is little if any support for the value propositions that were advanced when 12-h shifts were introduced. While 12-h shifts might be here to stay, it is important that the limitations, including reduced productivity and efficiency, are recognised and accepted by those in charge of implementing schedules for hospital nurses.

Impact of fatigue on nursing care rationing in paediatric haematology and oncology departments - a cross-sectional study

Background

Rationing of nursing care is a relatively new concept. It refers to an error of omission and has a direct influence on the quality of nursing care and treatment outcomes. Nurses who experience chronic fatigue often fail to perform their duties properly, which may lead, for instance, to medical errors attributed to impaired judgment. Therefore, it is necessary to identify factors which give rise to fatigue, leading to rationing of nursing care, and develop strategies to eliminate them. The primary objective of the study was to assess the impact of fatigue on nursing care rationing in paediatric haematology and oncology departments. The secondary objective of this study was to identify the factors, which may influence the nursing care rationing.

Methods

The study was conducted among 95 nurses (aged between 23 and 58 years) workinginthe Department of Paediatric Oncology, Haematology and Bone Marrow Transplantation of the University Teaching Hospital in Wroclaw. Participation in the study was voluntary and anonymous. Our own sociodemographic questionnaire, the Basel Extent of Rationing of Nursing Carequestionnaire and the modified fatigue impact scale (MFIS) were used in the study.

Results

The level of fatigue among the nurses participating in the study, as measured by the MFIS, was high, namely 28.97 ± 16.78. It was found that the fatigue of the nurses influenced most often the psycho-social dimension of QoL (1.78 ± 1.05), and least often - cognitive (1.24 ± 0.78). A correlation analysis showed that all aspects of fatigue had a statistically significant positive impact on care rationing (p < 0.05), i.e. the greater the fatigue, the higher the level of care rationing. A regression analysis showed that a 12-h shift pattern was an independent predictor of the level of care rationing (r = 0.771, p < 0.05).

Conclusions

Nurses working in paediatric haematology departments report a high level of fatigue. Work pattern is an independent determinant of nursing carerationing. A high level of nursing care rationing was found for nurses working 12-h shifts.

Trial registration

The study was approved by the Bioethics Committee of the Wroclaw Medical University, Poland (February 8th 2019, No. 205/2019).

Nurses' 12-hour shifts and missed or delayed vital signs observations on hospital wards: retrospective observational study

OBJECTIVES

12-hour shifts worked by nurses on acute hospital wards have been associated with increased rates of missed care reported by nurses. This study aimed to measure the association between nurses working shifts of at least 12 hours and an objective measure of missed care: vital signs observations taken on time according to an acuity-based surveillance protocol.

DESIGN

A retrospective observational study using routinely collected data from March 2012 to March 2015.

SETTING

32 general inpatient wards at a large acute hospital in England.

PARTICIPANTS

658 628 nursing shifts nested in 24 069 ward days.

OUTCOME MEASURES

The rate of daily delayed and missed vital signs observations. We focused on situations where vital signs observations were required at least every 4 hours and measured the number of instances where observations were delayed or missed, per 24-hour period. For each ward and each day, shift patterns were characterised in terms of proportion of care hours per patient day deriving from 'long' shifts (≥12 hours) for both registered nurses and healthcare assistants.

RESULTS

On 99 043 occasions (53%), observations were significantly delayed, and on 81 568 occasions (44%), observations were missed. Observations were more likely to be delayed when a higher proportion of the hours worked by healthcare assistants were part of long shifts (IRR=1.05; 95% CI 1.00 to 1.10). No significant association was found in relation to the proportion of hours registered nurses worked as long shifts.

CONCLUSION

On days when a higher proportion of hours worked by healthcare assistants are from long shifts, the risk of delaying vital signs observations is higher, suggesting lower job performance. While longer shifts are thought to require fewer staff resources to maintain nurse-to-patient ratios, any benefits may be lost if staff become less productive.

Association between 12-hr shifts and nursing resource use in an acute hospital: Longitudinal study

Aim

To evaluate whether ≥12‐hr shifts are associated with a decrease in resource use, in terms of care hours per patient day and staffing costs per patient day.

Background

Nurses working long shifts may become less productive and no research has investigated whether potential cost savings are realized.

Method

A retrospective longitudinal study using routinely collected data from 32 wards within an English hospital across 3 years (1 April 2012–31 March 2015). There were 24,005 ward‐days. Hierarchical linear mixed models measured the association between the proportion of ≥12‐hr shifts worked on a ward‐day, care hours per patient day and staffing costs per patient day.

Results

Compared with days with no ≥12‐hr shifts, days with between 50% and 75% ≥12‐hr shifts had more care hours per patient day and higher costs (estimate for care hours per patient day: 0.32; 95% CI: 0.28–0.36; estimate for staffing costs per patient day: £8.86; 95% CI: 7.59–10.12).

Conclusions

We did not find reductions in total care hours and costs associated with the use of ≥12‐hr shifts. The reason why mixed shift patterns are associated with increased cost needs further exploration.

Implications for Nursing Management

Increases in resource use could result in additional costs or loss of productivity for hospitals. Implementation of long shifts should be questioned.

A comparison of a 12-hour and eight-hour shift system in similar medical wards

Despite the increasing use of and discussion about 12-hour shifts, little work has been carried out in the United Kingdom to assess its impact. A study was carried out to compare two medical wards which had been operating a 12-hour shift for more than one year with two medical wards which had carried on with a conventional shift system over the same period of time. Staff questionnaires, interviews, patient interviews, documentation review, and analysis of a number of organizational issues were undertaken to evaluate the effect of the shift pattern worked. Viewing this shift pattern from a variety of perspectives indicates that there were no significant differences between the shift patterns with regard to staff perception, patient perception, documentation and organisational issues. However, some aspects of the 12-hour shift produced more favourable responses from the staff: less fatigue was reported by those working the 12-hour shift and documentation was more complete on these wards. However, the length of time available for the handover was identified as a problematic area. Staff surveyed had chosen to work these hours which may positively have influenced the impact of this shift pattern on both staff and patients. This work demonstrates the complexities in evaluating patterns of work in providing patient care over 24 hours.

Issues involved in introducing the 12-hour shift

The requirement to ensure that practice is evidence-based, means that all aspects of the structure, process and outcome of nursing care need to be subjected to critical review. This report attempts to do this in regard to the 12-hour shift pattern. Twelve-hour shifts are being introduced by an increasing number of managements, a practice which has raised concerns since there is some evidence indicating that 12-hour shifts affect the amount of care patients receive, and that there are possible links between length of shift worked, nurses' stress and fatigue levels and the impact these might have on the quality of care. This review discusses the main effects of the change in shifts on nurses and patients alike. The review focuses on studies since 1980 and on studies carried out in the United Kingdom. The search produced a considerable number of references; however, only those which met the inclusion criteria are included in this paper; a complete list is available on request. Much of the published work currently available lacks rigour. Yet, this is an important topic on which sound information is needed to inform decision-making.

Nurse Continuity and Hospital-Acquired Pressure Ulcers: A Comparative Analysis Using an Electronic Health Record "Big Data" Set

BACKGROUND

Little research demonstrating the association between nurse continuity and patient outcomes exists despite an intuitive belief that continuity makes a difference in care outcomes.

OBJECTIVE

The aim of this study was to examine the association of nurse continuity with the prevention of hospital-acquired pressure ulcers (HAPU).

METHODS

A secondary use of data from the Hands on Automated Nursing Data System (HANDS) was performed for this comparative study. The HANDS is a nursing plan of care data set containing 42,403 episodes documented by 787 nurses, on nine units, in four hospitals and includes nurse staffing and patient characteristics. The HANDS data set resides in a "big data" relational database consisting of 89 tables and 747 columns of data. Via data mining, we created an analytic data set of 840 care episodes, 210 with and 630 without HAPUs, matched by nursing unit, patient age, and patient characteristics. Logistic regression analysis determined the association of nurse continuity and additional nurse-staffing variables on HAPU occurrence.

RESULTS

Poor nurse continuity (unit mean continuity index = .21-.42 [1.0 = optimal continuity]) was noted on all nine study units. Nutrition, mobility, perfusion, hydration, and skin problems on admission, as well as patient age, were associated with HAPUs (p < .001). Controlling for patient characteristics, nurse continuity, and the interactions between nurse continuity and other nurse-staffing variables were not significantly associated with HAPU development.

DISCUSSION

Patient characteristics including nutrition, mobility, and perfusion were associated with HAPUs, but nurse continuity was not. We demonstrated a high level of variation in the degree of continuity between patient episodes in the HANDS data, showing that it offers rich potential for future study of nurse continuity and its effect on patient outcomes.

Proposing a New Conceptual Model and an Exemplar Measure Using Health Information: Technology to Examine the Impact of Relational Nurse Continuity on Hospital-Acquired Pressure Ulcers

The influence of the staffing variable relational nurse continuity on patient outcomes has been rarely studied and with inconclusive results. Multiple definitions and an absence of systematic methods for measuring the influence of continuity have resulted in its exclusion from nurse-staffing studies and conceptual models. We present a new conceptual model and an innovative use of health information technology to measure relational nurse continuity and to demonstrate the potential for bringing the results of big data science back to the bedside. Understanding the power of big data to address critical clinical issues may foster a new direction for nursing administration theory development.

12-h or 8-h shifts? It depends

Since 12-h shifts were first implemented, the question has been asked - are 'twelves' better than 'eights'? People trying to answer this question invariably refer to the limited literature at their disposal, often piecemeal, small-scale studies comparing 8-h versus 12-h shifts in isolated groups of workers in which many other factors vary concurrently. The narrow perspective and sometimes 'vested interests' of the organizations, researchers, publishers and individual workers can influence both the choice of measures, the analysis of results and their interpretation. The current review suggests that it is not sufficient to evaluate a shift pattern on the basis of a single dimension of a working time arrangement, such as shift length. Numerous factors associated with the work practice influence the outcome of a shift pattern including start times, pattern of shifts and amount of overtime. Moreover, the type of work being done and the demographics or characteristics of the workforce are additional mediating factors. Finally, and perhaps most critically, the relative importance assigned to different outcome measures is an important consideration. There are situations where total sleep time might increase following a change to 12-h shifts, whereas domestic life for some workers may deteriorate. Additionally, safety measures may show improvements on 8-h shifts but physical or psychological health outcomes may be worse. The myriad combinations of work pattern, work task, worker and outcome measure under investigation mean that the best way to take account of these complexities may be to use an approach that manages 'system' risk. Given the non-linearities in the system, and the fact that current approaches either ignore, or privilege a subset of outcomes, it is perhaps more appropriate to conceptualize working time arrangements as an 'ecosystem' and to address the risks in the overall system as opposed to a single dimension such as shift length.

Critical care: the impact of organization and management on outcomes

PURPOSE OF REVIEW

The organization and management of ICUs are key components that can affect delivery and outcome of critical care.

RECENT FINDINGS

At the healthcare system level, the provision of critical care services and the presence of a regionalized system of critical care delivery may improve optimal matching of patient severity with level of care and is associated with improved patient outcomes. In hospitals, rapid response teams and step-down beds affect admission and discharge criteria to and from the ICU, although the influence on outcome is unclear. And within the ICU, the presence of intensivists, physically or via telemedicine, and multidisciplinary teams may promote better use of therapeutic and preventive measures with improved patient outcomes. Recent findings also emphasize that strategies that promote teamwork and communication, standardize processes of care, emphasize engagement in quality improvement, and provide a positive safety culture are associated with improved patient outcomes and staff morale.

SUMMARY

Evidence suggests the implementation of some ICU organizational and managerial patterns are associated with improved patient and staff outcomes. Broader adoption of some of these strategies could, therefore, improve overall critical care delivery.

Physiological and behavioural response patterns at work among hospital nurses

AIM

The aim was to determine whether hospital nurses are experiencing physiological strain at work by examining their physiological and behavioural response patterns over 12-hour shifts.

BACKGROUND

Excessive workload for nurses may lead to poor quality of care and high nursing turnover rates. Energy expenditure (EE), heart rate (HR) and work pace (WP) can be used to examine the physiological impact from the workload.

METHODS

A total of 145 nurses wore monitors for one 12-hour day shift to record HR and WP, which were used to calculate EE. Individual and work-related factors were assessed through questionnaires and work logs.

RESULTS

Energy expenditure accumulated over the 12 hours reached the EE level of 8-hour shifts in which individuals work at a moderate physical intensity level. The HR data indicated a moderate cardiac stress level throughout the shifts, despite which WP decreased after 15.00 hours. Inadequate work break and sleep, family care-giving responsibility and aging may challenge work recovery.

CONCLUSIONS

Nursing workload of 12-hour shifts has a negative physiological impact on hospital nurses.

IMPLICATIONS FOR NURSING MANAGEMENT

Nurse managers need to be aware of the physiological strain experienced by staff nurses, and focus on ensuring sufficient breaks and proper work accommodations for older nurses.

A systematic review of the neurobehavioural and physiological effects of shiftwork systems

Shiftwork is a common experience for many workers. There are a wide range of shift systems in use, with a number of general approaches and myriad variations of each one. Many aspects of shift systems have been studied, but attempts to reach definitive conclusions about appropriate designs have been hampered by a number of methodological issues. The aim of this systematic review was to provide evidence-based recommendations on the effect of various shift systems on neurobehavioural and physiological functioning and to identify areas which are lacking in appropriate evidence. Two main aspects of shift design were able to be considered-the direction of shift rotation and extended shift length (mainly 12-h shifts). Other areas for which there was at least one relevant paper of adequate methodology were the use of naps during night shifts, the starting time of shifts, and several other specific shift issues. Overall, the review found there is insufficient evidence to support definitive conclusions regarding any of these factors. However, the analysis provides support for the use of forward rotating shift systems in preference to backward rotating shift systems, at last as far as 8-h shifts are concerned. There are many unanswered questions in shift design. For these questions to be answered, it is important that the methodological shortcomings present in most of the studies published to date be overcome.

Extended work periods

A literature review of 105 studies on the effects of extended daily working hours was conducted. Potential negative effects of extended working hours are discussed: More accidents on the job; more accidents off the job; reduced duration and quality of sleep due to moonlighting; sleepiness; reduced alertness; fatigue; adverse effects on performance; prolonged toxic exposure; adverse effects on health; increased absenteeism; problems communicating with managers; and problems while driving home. Potential positive effects of extended working hours are discussed: Less travel time and costs; more time for the family, social life, and domestic duties; increased satisfaction with working hours; fewer handovers; and less overtime. No firm conclusions can be drawn because of the partly contradictory results and the methodological problems of many studies. However, caution is advised when considering the introduction of extended work shifts, particularly where public safety is at stake. A checklist is provided (concerning work load, breaks, staffing level, systematic assessments of health and safety factors) to support decisions for or against the use of extended work shifts.

Critical care nurses - perceptions of 12-h shifts

BACKGROUND

Twelve-hour shifts have been illustrated in the literature as being a highly contentious shift pattern. However, it has also been highlighted that there is a distinct paucity of literature solely related to such a shift pattern in critical care areas, where there is high activity and a requirement for multiple and highly significant decision-making situations. It was therefore identified that such an area deserved further exploration.

AIM

This study aimed to elicit critical care nurses' perceptions of working 12-h shifts.

METHODS

Fifty-four nurses from three critical care areas within a large local NHS teaching hospital currently working 12-h shifts completed a self-administered questionnaire on their perceptions of 12-h shifts. Following on, a focus group interview was conducted to complement this questionnaire in an attempt to further explore these perceptions.

RESULTS

From the results of the questionnaire, patient care, job satisfaction, off duty and family life achieved the most positive responses, whereas communication, fatigue and education achieved the most negative. The focus group explored these issues with added comments on work-shy staff, suggestions on shift patterns, breaks and staffing levels.

CONCLUSIONS

Twelve-hour shifts in critical care areas are suitable shift patterns for nurses, patients and management, provided that they are fundamentally well-managed.

Nursing Activities and Use of Time in the Postanesthesia Care Unit

Specialty areas, such as the PACU, are currently characterized by a shortage of qualified nursing personnel along with the pressure for a most cost-conscious function of services. These, in combination with both the increasing acuity of patients and the advances of science and technology, have rendered necessary the investigation of how existing personnel can be better used. The work sampling approach has been widely used in different clinical settings to offer data about the amount of time nurses devote to specific activities. The aim of the current study was to categorize and quantify the activities of nurses employed in the PACU of the General University Hospital of Patras, Greece, and to identify differences with regard to shifts, varying nurse-patient ratios, and nurses' experiences. In the first phase, a classification form, which included all nursing activities, was constructed. This was based on literature review, researchers' experience, and semistructured personnel interviews. In the second phase, the researchers observed all PACU nurses, and activities were recorded on an hourly check sheet. A total of 4,320 observations were collected from 9/1/2004 to 9/30/2004. Nurses spent 35.2% of their time on direct clinical care, 11.6% on patient assessment, 7.0% on communication with patients, 7.2% on communication with other persons, 8.6% on clerical nursing duties, 9.3% on documentation, 2.3% on non-nursing duties, and 18.8% on personal activities. Variations in the use of time were found between shifts, different nurse-patient ratios, and PACU experience. Methods of decreasing time when the nurse-patient ratio is inappropriate and increasing time allocated to direct care activities are proposed.

The Effects of Work Breaks on Staff Nurse Performance

OBJECTIVE

To determine if skipping breaks and meal periods increases the risk of errors.

BACKGROUND

Anecdotal data suggest that staff nurses frequently skip their breaks and/or meal periods to provide patient care. Neither the prevalence nor the impact of this practice on patient safety is known.

METHODS

Three hundred ninety-three nurses completed logbooks for 28 days providing information about their work hours, errors, and episodes of drowsiness and actual sleep on duty. Participants were asked if they were able to take a break or sit down for a meal during their shift, to indicate the total duration of breaks taken during the shift, and if they were relieved of patient care responsibilities during their meals and/or break periods.

RESULTS

Nurses reported having a break or meal period free of patient care responsibilities less than half of the shifts they worked (2,429/5,211 shifts). There were no differences in the risk of errors reported by nurses who had a break free of patient care responsibilities compared with those who were unable to take a break.

CONCLUSIONS

Although skipping breaks and/or meal periods was not associated with a higher risk of making errors, there are other compelling reasons for nurses to take breaks.

The effects of extended workdays on fatigue, health, performance and satisfaction in nursing

BACKGROUND

Several authors have claimed that 12-hour shifts in nursing are better for both employees and patient care. However, although the research has found positive effects on satisfaction with working hours and free time, the effects on employee fatigue, health and performance have mostly been neutral or negative.

AIM

Work schedules should preferably be beneficial for satisfaction, fatigue, health and performance. This study therefore investigated whether shifts that are extended only slightly can combine the positive effects of the 12-hour shift with the positive effects of the 8-hour shift. The study investigated the effects of 9-hour shifts.

METHOD

A total of 134 nurses from three nursing homes in the Netherlands completed a questionnaire on fatigue, health, performance and satisfaction. One group worked 8-hour shifts, and the other worked 9-hour shifts.

RESULTS

Nurses who worked 9-hour shifts were on average more fatigued, had more health complaints, and were less satisfied with their working hours and free time than those who worked 8-hour shifts. Their performance was slightly poorer. About 70% to 80% of the 8- and 9-hour nurses preferred to work a maximum of 8 hours during morning/early and afternoon/late shifts.

CONCLUSIONS

The 9-hour shift seemed to combine the negative aspects of the 12-hour shift with the negative aspects of the 8-hour shift. It is suggested that the 9-hour shift had more negative effects than the 12-hour shift because: (1) nurses could not choose what shift length they worked; (2) many worked part-time; and (3) they already had many days off. It is also suggested that increases in workload since the 1980s make current extended shifts in nursing more fatiguing.

Twelve-hour shift on ITU: a nursing evaluation

This paper describes the introduction and subsequent evaluation of a 12-h shift system in a large ITU in the northeast of UK. To date, only a small number of studies has evaluated nurses working the 12-h shifts in critical care areas. To evaluate the level of staff satisfaction, data were collected by means of a questionnaire involving 41 nurses, at 3 months following the introduction of the 12-h shifts. The responses from the evaluation advocated the continuation of 12-h shifts with alternative shift patterns for nurses who felt dissatisfied with the current system. Twelve-hour shifts can be seen as a flexible system for nurses working in intensive care and may assist with staff satisfaction and improving nurse recruitment and retention.

Evaluation of 12-hour shifts on a cardiology nursing development unit

The first part of this two-part article discussed the implementation of 12-hours shifts using a locally devised nursing development unit (NDU) framework (Vol 9(19): 2095-9). This article, the second part, discusses the results of a survey to evaluate the 12-hour shifts, the problems encountered during the implementation of 12-hours shifts, the solutions and the NDU framework as described in the first part of the article. A qualitative design to the postal survey was chosen with the resulting data being subjected to a content analysis. Data triangulation compared survey results with incident reports and sickness records. The limitations of the survey included having the change agent analysing the data, the sampling method and being unable to pilot the questionnaire. The results indicated an improvement in the quality of patient care, although this is difficult to measure, a pacing of workload throughout the day, and tiredness during, after and at the end of a stretch of shifts. Other results centred on staff morale, social life, student nurses' experience and night shifts. The solutions to identified problems included the employment of two twilight nurses to help the night staff during the busy early evening period. As a requirement of the NDU framework, standards were produced from the survey results, as this would allow subsequent audit of the 12-hour shift system. The recommendations from this survey included the dissemination of results both locally and nationally to expand the body of nursing knowledge and to promote practice based on the best available evidence.

Implementing 12-hour shifts on a cardiology nursing development unit

This article, the first of two parts, discusses the implementation of 12-hour shifts using a locally devised nursing development unit (NDU) framework. A literature review and force-field analysis were undertaken to plan, implement and evaluate the introduction of the 12-hour system. The literature review identified five broad categories: effect on care delivery; nurse education; cost-effectiveness; impact on staff; and implementation strategies. It also ascertained that the most successful methods of implementation were those that gained the cooperation of staff. The force-field analysis identified the restraining forces (e.g. tiredness, the European Working Time Directive and staff views) and therefore allowed the change agent to concentrate his limited time on combating these restraining forces. The second part of this series will examine the evaluation and audit of the 12-hour shift system.

Work shift duration: a review comparing eight hour and 12 hour shift systems

OBJECTIVES

Shiftwork is now a major feature of working life across a broad range of industries. The features of the shift systems operated can impact on the wellbeing, performance, and sleep of shiftworkers. This paper reviews the current state of knowledge on one major characteristic of shift rotas-namely, shift duration. Evidence comparing the relative effects of eight hour and 12 hour shifts on fatigue and job performance, safety, sleep, and physical and psychological health are considered. At the organisational level, factors such as the mode of system implementation, attitudes towards shift rotas, sickness absence and turnover, overtime, and moonlighting are discussed.

METHODS

Manual and electronic searches of the shiftwork research literature were conducted to obtain information on comparisons between eight hour and 12 hour shifts.

RESULTS

The research findings are largely equivocal. The bulk of the evidence suggests few differences between eight and 12 hour shifts in the way they affect people. There may even be advantages to 12 hour shifts in terms of lower stress levels, better physical and psychological wellbeing, improved durations and quality of off duty sleep as well as improvements in family relations. On the negative side, the main concerns are fatigue and safety. It is noted that a 12 hour shift does not equate with being active for only 12 hours.

CONCLUSIONS

There can be considerable extension of the person's time awake either side of the shift. However, the effects of longer term exposure to extended work days have been relatively uncharted in any systematic way. Longitudinal comparative research into the chronic impact of the compressed working week is needed.

Extended workshifts and excessive fatigue

Studies of overtime have pointed to fatigue as a potential factor producing, for example, a three-fold increase in accident rate after 16 h of work, increases in back injuries, hospital outbreaks of bacterial infection, or nuclear-power plant safety compromises. Fatigue has been measured more directly in studies of scheduled long workshifts, where performance decrements in both work-related tasks and laboratory-type behavioural tests have been observed, and significant loss of sleep and increases in subjective sleepiness have been reported. Analyses of accidents or injuries during scheduled extended workshifts, however, have produced equivocal results. Factors which could compound the fatiguing effects of extended workshifts, such as workload, noise, chemical exposure, or duties and responsibilities outside of the workplace, rarely have been studied systematically. It is concluded that extended workshift schedules should be instituted cautiously and evaluated carefully, with appropriate attention given to staffing levels, workload, job rotation, environmental exposures, emergency contingencies, rest breaks, commuting time, and social or domestic responsibilities.