The current article is, to our knowledge, the first prospective study conducted in an NHS hospital in the United Kingdom on the effects of a 48 h/week EWTD-compliant rota on patient care, as assessed objectively from medical error rates. The study shows that 33% fewer medical errors occurred on an intervention rota with shifts up to 48 h, as compared to a traditional 56 h/week schedule. While differences in clinical specialty may explain some differences in error rates between rotas, the study suggests that implementation of a 48 h work week can be accomplished without an adverse effect on patient safety. Notably, the study was conducted during a difficult period for junior doctors when many of them were involved in applying for training posts under the Medical Training Application Service (MTAS) scheme which caused well-publicized dissatisfaction and had a negative effect on the morale of many of those participating.24
Nevertheless the results are striking.
There has been considerable controversy regarding the appropriateness of implementing the EWTD in the NHS. Concerns have been raised that the new directive would put doctors’ and patients’ lives at risk25
, would lead to reduced time available for training, will have negative impacts on clinical experience and quality of care.26–28
These strong assertions are, without exception, based on opinions, anecdotes or non-validated questionnaires and surveys.29–32
Our study is the first objective assessment of the impact of 2009 EWTD-compliant schedules on patient care, the primary concern of healthcare providers, and presents scientific evidence upon which to begin basing policy decisions.
In 2006 the Royal College of Physicians Multidisciplinary Working Group recommended (i) that rotas involving seven consecutive 13 h night shifts must be stopped due to their inherent high risk of fatigue and potential harm to patients and staff; (ii) that the number of night shifts in succession should not exceed four and the length of each night shift should be minimized; (iii) to encourage the use of three 9 h shifts to cover 24 h with the aim of improving patient health and safety, junior doctors’ safety, teaching, supervision and efficiency; (iv) to use evidence-based approaches in order to define optimal 48 h rotas by 2009; (v) that a ‘cell’ of 10 junior doctors is necessary for any post that provides 24 h cover.12
Inspired by the RCP recommendations, we proposed a study to test the feasibility of implementing a EWTD-compliant 48 h a week schedule and to assess objectively its impact on patient safety. The intervention rota was based on the schedule that the RCP proposed as the most promising in its review in minimizing the risk to patient safety and doctors’ health with particular regard to the length and frequency of night shifts.12
The intervention rota had several important components that were based on well-established principles of sleep medicine and circadian biology.14,33
First, it limited consecutive night shifts to three nights maximum and for the majority of weeks, only two, in order to reduce the build-up of chronic partial sleep deprivation due to the limited sleep between night shifts. Second, shift duration was limited to 12 h maximum in order to minimize acute sleep deprivation, which represented a distinct difference from the current 56 h a week rota which scheduled 25% of shifts >12 h. Third, the sequence of shifts was designed to abolish ‘slam shifts’ in which doctors change from a day to a night shift immediately, which ensures complete circadian desynchrony,34
and instead gradually stagger the shifts from morning to evening to night in the direction that the circadian system most easily adapts to.35
This sequence also facilitates sleep and reduces performance decrements on the first night shift36
by providing an opportunity for a long recovery sleep after the evening shift prior to starting the first night shift. Finally, the intervention rota dramatically reduced the proportion of long work weeks, with an upper limit of 60 h per week, again reducing chronic sleep deprivation, in stark contrast to the current 56 h rota, during which 25% of the shifts were >58 h/week and as long as 77 h/week.
Given that extended duration duty hours and long work weeks had previously been shown to be associated with increased risk to patient safety and resident health,4–5,9–10,37
we hypothesized that medical errors rates would be reduced following introduction of the 2009 EWTD-compliant 48 h a week rota as compared to the 56 h rota currently in use. Indeed, we found that significantly fewer errors occurred on the 48 h rota as compared to the 56 h rota. This proportional benefit is comparable to that found in our previous study in medical- and cardiac-intensive care units in the United States4
although it must be noted that the US study was carried out in units where the absolute rate of errors, given the intensity of work, was much higher than we found in medical wards. It also appears, on first impression, that much more substantive rota changes were introduced in the US study (continuous scheduled duty changed from 24–30 h to 16 h and scheduled work weeks changed from 80 h/week to 63 h/week).4
On closer inspection, however, the fact that the 56 h EWTD regulations allow averaging weekly work hours over 6 months permits work weeks in the UK that, during some weeks, are comparable to the US limit of 80 h a week averaged over 4 weeks.38
We have previously argued that such weekly limit terms are misleading14
given that, in both the United States and UK, weekly work hours can be much longer than the nominal ‘limits’ if they are balanced by shorter weeks elsewhere in the rota. We believe that in the current study, the reduction in error rates observed may have been due to the effect of the intervention on reducing the range of weekly work hours, rather than the average hours per week. The difference between 56 and 48 h/week on average may appear small, but the difference may be much greater in any given week, as doctors still work nearly 80 h a week for some weeks under the current regulations.
In the study, only nine doctors worked on the intervention team while the traditional rota maintained its roster of 10 doctors. This imbalance was not ideal and the successes of the intervention study in improving work and sleep patterns, as well as the low rate of medical errors were, in part, offset by a number of unfavorable impressions of the intervention rota. The intervention rota resulted initially in too few doctors being available for duty during the day. The problems with reduced cover were precipitated by sick leave, annual leave and study leave. For a full implementation of our rota in future iterations of the schedule, these changes should be synchronized with normal hospital practices10
and should include more doctors, recently argued to be between 12 and 13 per cell28
, but at minimum 10. Nevertheless our study in NHS-based medical wards was able to detect significant differences in work hours with important implications for patients’ safety, despite doctors’ perceptions that the new rota would worsen care and represent harm to patients.
As in a previous study,4
the reduction in medical errors was achieved despite a modest increase in the number of handovers, which may be a source of error in its own right.39
Regardless of shift length, the process of handing over care between shifts is error-prone, and should be a focus of future improvement efforts. Introduction of computerized handover tools40–41
or standardized, consistent verbal handover procedures could further improve patient safety on these rotas.
The study has several limitations. The two study groups were working in different wards so the case mix was different between the groups. Respiratory and Endocrine groups were similar in terms of doctors’ duties, though the medications and interventions employed differed somewhat, which may have affected detected rates of medical errors. The CDU differed substantially from both of these units, in that the patients were all emergency admissions; the Care of the Elderly also differed substantially, with longer length of stay and a higher proportion of patients who were terminally ill and in need of palliative care. The marked nature of the differences between the CDU and Care of the Elderly Wards precluded any reasonable comparison. As the Endocrine and Respiratory wards were more similar, we felt it reasonable to comparatively evaluate error rates between these two, but we do so with some caution; larger, closely controlled studies will be needed to confirm our findings.
Direct observation identifies higher error rates than other techniques but its cost and organizational implications limit its use.42
Retrospective case reviews is the most widely used clinical surveillance methodology for detecting medical errors and adverse events; rates of adverse events ranging from 2.9 to 16.6% have been reported from centres in North America and Australasia.43
A study in two acute hospital wards in the UK found an incidence rate of 11.7%.44
Retrospective case note review, as used in this study, is less expensive and labour intensive than observation but nevertheless time-consuming and may not provide such a clear cut view of events especially since it is entirely dependent on the ‘accuracy, completeness and legibility’ of medical records.45
These limitations applied to both study groups, however, and the physician review of errors was conducted blind to condition.
Our study was too short and not designed to assess the impact of the new 48 h rota on educational opportunities. Educational issues are intertwined with both patient safety issues and doctors well-being in the context of a training post. While the reduction of educational opportunities was raised as a concern, there are as yet no data testing the impact of shorter work hours on validated educational outcomes. Indeed, we could hypothesize that reducing work hours may enhance educational outcomes given the emerging importance of sleep in learning and memory consolidation46
and the difficulty with learning while ‘half asleep’ on duty.6
Additional controlled trials are needed to test these hypotheses.
While our intervention reduced the length of continuous duty and work week duration with the aim of reducing sleepiness and improving performance, most doctors did not consider that sleepiness was a major problem. These comments are not surprising given that self-ratings of sleepiness when sleep deprived do not reflect objective measurements of poor performance. Similar to the misperception of one's own performance induced by alcohol, sleep deprived subjects rate their alertness as better than their performance demonstrates.47,48
This example illustrates a larger point, however, namely that policy decisions should not be made based on subjective opinions. Such unsubstantiated preconceptions are not valid when designing safe schedules. Decisions regarding work hour reform should be based on data derived from controlled clinical trials data, just as objective data form the basis of evidence-based medical decision.12
Our current data represent the first step in this process and should be followed by additional hypothesis-driven studies.