The magnitude and mechanisms of the weekend effect in hospital admissions: A protocol for a mixed methods review incorporating a systematic review and framework synthesis

Neonatal mortality in NHS maternity units by timing and mode of birth: a retrospective linked cohort study

OBJECTIVES

To compare neonatal mortality in English hospitals by time of day and day of the week according to care pathway.

DESIGN

Retrospective cohort linking birth registration, birth notification and hospital episode data.

SETTING

National Health Service (NHS) hospitals in England.

PARTICIPANTS

6 054 536 liveborn singleton births from 2005 to 2014 in NHS maternity units in England.

MAIN OUTCOME MEASURES

Neonatal mortality.

RESULTS

After adjustment for confounders, there was no significant difference in the odds of neonatal mortality attributed to asphyxia, anoxia or trauma outside of working hours compared with working hours for spontaneous births or instrumental births. Stratification of emergency caesareans by onset of labour showed no difference in mortality by birth timing for emergency caesareans with spontaneous or induced onset of labour. Higher odds of neonatal mortality attributed to asphyxia, anoxia or trauma out of hours for emergency caesareans without labour translated to a small absolute difference in mortality risk.

CONCLUSIONS

The apparent 'weekend effect' may result from deaths among the relatively small numbers of babies who were coded as born by emergency caesarean section without labour outside normal working hours. Further research should investigate the potential contribution of care-seeking and community-based factors as well as the adequacy of staffing for managing these relatively unusual emergencies.

The effect of weekends and public holidays on the care of acute coronary syndrome in the Spanish National Health System

INTRODUCTION AND OBJECTIVES

To analyze whether admission on weekends or public holidays (WHA) influences the management (performance of angioplasty, percutaneous coronary intervention [PCI]) and outcomes (in-hospital mortality) of patients hospitalized for acute coronary syndrome in the Spanish National Health System compared with admission on weekdays.

METHODS

Retrospective observational study of patients admitted for ST-segment elevation myocardial infarction (STEMI) or for non-ST-segment elevation acute coronary syndrome (NSTEACS) in hospitals of the Spanish National Health system from 2003 to 2018.

RESULTS

A total of 438 987 episodes of STEMI and 486 565 of NSTEACS were selected, of which 28.8% and 26.1% were WHA, respectively. Risk-adjusted models showed that WHA was a risk factor for in-hospital mortality in STEMI (OR, 1.05; 95%CI,1.03-1.08; P < .001) and in NSTEACS (OR, 1.08; 95%CI, 1.05-1.12; P < .001). The rate of PCI performance in STEMI was more than 2 percentage points higher in patients admitted on weekdays from 2003 to 2011 and was similar or even lower from 2012 to 2018, with no significant changes in NSTEACS. WHA was a statistically significant risk factor for both STEMI and NSTEACS.

CONCLUSIONS

WHA can increase the risk of in-hospital death by 5% (STEMI) and 8% (NSTEACS). The persistence of the risk of higher in-hospital mortality, after adjustment for the performance of PCI and other explanatory variables, probably indicates deficiencies in management during the weekend compared with weekdays.

Increasing specialist intensity at weekends to improve outcomes for patients undergoing emergency hospital admission: the HiSLAC two-phase mixed-methods study

Background

NHS England’s 7-day services policy comprised 10 standards to improve access to quality health care across all days of the week. Six standards targeted hospital specialists on the assumption that their absence caused the higher mortality associated with weekend hospital admission: the ‘weekend effect’. The High-intensity Specialist-Led Acute Care (HiSLAC) collaboration investigated this using the implementation of 7-day services as a ‘natural experiment’.

Objectives

The objectives were to determine whether or not increasing specialist intensity at weekends improves outcomes for patients undergoing emergency hospital admission, and to explore mechanisms and cost-effectiveness.

Design

This was a two-phase mixed-methods observational study. Year 1 focused on developing the methodology. Years 2–5 included longitudinal research using quantitative and qualitative methods, and health economics.

Methods

A Bayesian systematic literature review from 2000 to 2017 quantified the weekend effect. Specialist intensity measured over 5 years used self-reported annual point prevalence surveys of all specialists in English acute hospital trusts, expressed as the weekend-to-weekday ratio of specialist hours per 10 emergency admissions. Hospital Episode Statistics from 2007 to 2018 provided trends in weekend-to-weekday mortality ratios. Mechanisms for the weekend effect were explored qualitatively through focus groups and on-site observations by qualitative researchers, and a two-epoch case record review across 20 trusts. Case-mix differences were examined in a single trust. Health economics modelling estimated costs and outcomes associated with increased specialist provision.

Results

Of 141 acute trusts, 115 submitted data to the survey, and 20 contributed 4000 case records for review and participated in qualitative research (involving interviews, and observations using elements of an ethnographic approach). Emergency department attendances and admissions have increased every year, outstripping the increase in specialist numbers; numbers of beds and lengths of stay have decreased. The reduction in mortality has plateaued; the proportion of patients dying after discharge from hospital has increased. Specialist hours increased between 2012/13 and 2017/18. Weekend specialist intensity is half that of weekdays, but there is no relationship with admission mortality. Patients admitted on weekends are sicker (they have more comorbid disease and more of them require palliative care); adjustment for severity of acute illness annuls the weekend effect. In-hospital care processes are slightly more efficient at weekends; care quality (errors, adverse events, global quality) is as good at weekends as on weekdays and has improved with time. Qualitative researcher assessments of hospital weekend quality concurred with case record reviewers at trust level. General practitioner referrals at weekends are one-third of those during weekdays and have declined further with time.

Limitations

Observational research, variable survey response rates and subjective assessments of care quality were compensated for by using a difference-in-difference analysis over time.

Conclusions

Hospital care is improving. The weekend effect is associated with factors in the community that precede hospital admission. Post-discharge mortality is increasing. Policy-makers should focus their efforts on improving acute and emergency care on a ‘whole-system’ 7-day approach that integrates social, community and secondary health care.

Future work

Future work should evaluate the role of doctors in hospital and community emergency care and investigate pathways to emergency admission and quality of care following hospital discharge.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 13. See the NIHR Journals Library website for further project information.

Developing and evaluating a pediatric asthma severity computable phenotype derived from electronic health records

BACKGROUND

Extensive data available in electronic health records (EHRs) have the potential to improve asthma care and understanding of factors influencing asthma outcomes. However, this work can be accomplished only when the EHR data allow for accurate measures of severity, which at present are complex and inconsistent.

OBJECTIVE

Our aims were to create and evaluate a standardized pediatric asthma severity phenotype based in clinical asthma guidelines for use in EHR-based health initiatives and studies and also to examine the presence and absence of these data in relation to patient characteristics.

METHODS

We developed an asthma severity computable phenotype and compared the concordance of different severity components contributing to the phenotype to trends in the literature. We used multivariable logistic regression to assess the presence of EHR data relevant to asthma severity.

RESULTS

The asthma severity computable phenotype performs as expected in comparison with national statistics and the literature. Severity classification for a child is maximized when based on the long-term medication regimen component and minimized when based only on the symptom data component. Use of the severity phenotype results in better, clinically grounded classification. Children for whom severity could be ascertained from these EHR data were more likely to be seen for asthma in the outpatient setting and less likely to be older or Hispanic. Black children were less likely to have lung function testing data present.

CONCLUSION

We developed a pragmatic computable phenotype for pediatric asthma severity that is transportable to other EHRs.

Weekend readmissions associated with mortality following pancreatic resection for cancer

BACKGROUND

The weekend effect is associated with an increased risk of adverse events, with complex patient populations especially susceptible to its impact. The objective of this study was to determine if outcomes for patients readmitted following pancreas resection differed on the weekend compared to weekdays.

METHODS

The Healthcare Cost and Utilization State Inpatient Database for Florida was used to identify patients undergoing pancreas resection for cancer who were readmitted within 30 days of discharge following surgery. Measured outcomes (for readmission encounters) included inpatient morbidity and mortality.

RESULTS

Patients with weekend readmissions had an increased odds of inpatient mortality (aOR 2.7, 95% C.I.: 1.1-6.6) compared to those with weekday readmissions despite having similar index lengths of stay (15.9 vs. 15.5 days, P = .73), incidence of postoperative inpatient complications (22.4% vs. 22.3%, P = .98), reasons for readmission, and baseline comorbidity.

DISCUSSION

Weekend readmissions following pancreatic resection are associated with increased risk of mortality. This is not explained by measured patient factors or clinical characteristics of the index hospital stay. Developing strategies to overcome the weekend effect can result in improved care for patients readmitted on the weekend.

Magnitude and modifiers of the weekend effect in hospital admissions: a systematic review and meta-analysis

OBJECTIVE

To examine the magnitude of the weekend effect, defined as differences in patient outcomes between weekend and weekday hospital admissions, and factors influencing it.

DESIGN

A systematic review incorporating Bayesian meta-analyses and meta-regression.

DATA SOURCES

We searched seven databases including MEDLINE and EMBASE from January 2000 to April 2015, and updated the MEDLINE search up to November 2017. Eligibility criteria: primary research studies published in peer-reviewed journals of unselected admissions (not focusing on specific conditions) investigating the weekend effect on mortality, adverse events, length of hospital stay (LoS) or patient satisfaction.

RESULTS

For the systematic review, we included 68 studies (70 articles) covering over 640 million admissions. Of these, two-thirds were conducted in the UK (n=24) or USA (n=22). The pooled odds ratio (OR) for weekend mortality effect across admission types was 1.16 (95% credible interval 1.10 to 1.23). The weekend effect appeared greater for elective (1.70, 1.08 to 2.52) than emergency (1.11, 1.06 to 1.16) or maternity (1.06, 0.89 to 1.29) admissions. Further examination of the literature shows that these estimates are influenced by methodological, clinical and service factors: at weekends, fewer patients are admitted to hospital, those who are admitted are more severely ill and there are differences in care pathways before and after admission. Evidence regarding the weekend effect on adverse events and LoS is weak and inconsistent, and that on patient satisfaction is sparse. The overall quality of evidence for inferring weekend/weekday difference in hospital care quality from the observed weekend effect was rated as 'very low' based on the Grading of Recommendations, Assessment, Development and Evaluations framework.

CONCLUSIONS

The weekend effect is unlikely to have a single cause, or to be a reliable indicator of care quality at weekends. Further work should focus on underlying mechanisms and examine care processes in both hospital and community.

PROSPERO REGISTRATION NUMBER

CRD42016036487.

Births and their outcomes by time, day and year: a retrospective birth cohort data linkage study

Background

Studies of daily variations in the numbers of births in England and Wales since the 1970s have found a pronounced weekly cycle, with numbers of daily births being highest from Tuesdays to Fridays and lowest at weekends and on public holidays. Mortality appeared to be higher at weekends. As time of birth was not included in national data systems until 2005, there have been no previous analyses by time of day.

Objectives

To link data from birth registration and birth notification to data about care during birth and any subsequent hospital admissions and to quality assure the linkage. To use the linked data to analyse births and their outcomes by time of day, day of the week and year of birth.

Design

A retrospective birth cohort analysis of linked routine data.

Setting

England and Wales.

Outcome measures

Mortality of babies and mothers, and morbidity recorded at birth and any subsequent hospital admission.

Population and data sources

Birth registration and notification records of 7,013,804 births in 2005–14, already linked to subsequent death registration records for babies, children and women who died within 1 year of giving birth, were provided by the Office for National Statistics. Stillbirths and neonatal deaths data from confidential enquiries for 2005–9 were linked to the registration records. Data for England were linked to Hospital Episode Statistics (HES) and data for Wales were linked to the Patient Episode Database for Wales and the National Community Child Health Database.

Results

Cross-sectional analysis of all births in England and Wales showed a regular weekly cycle. Numbers of births each day increased from Mondays to Fridays. Numbers were lowest at weekends and on public holidays. Overall, numbers of births peaked between 09.00 and 12.00, followed by a much smaller peak in the early afternoon and a decrease after 17.00. Numbers then increased from 20.00, peaking at around 03.00–05.00, before falling again after 06.00. Singleton births after spontaneous onset and birth, including births in freestanding midwifery units and at home, were most likely to occur between midnight and 06.00, peaking at 04.00–06.00. Elective caesarean births were concentrated in weekday mornings. Births after induced labours were more likely to occur at hours around midnight on Tuesdays to Saturdays, irrespective of the mode of birth.

Limitations

The project was delayed by data access and information technology infrastructure problems. Data from confidential enquiries were available only for 2005–9 and some HES variables were incomplete. There was insufficient time to analyse the mortality and morbidity outcomes.

Conclusions

The timing of birth varies by place of birth, onset of labour and mode of birth. These patterns have implications for midwifery and medical staffing.

Future work

An application has now been submitted for funding to analyse the mortality outcomes and further funding will be sought to undertake the other outstanding analyses.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full inHealth Services and Delivery Research; Vol. 7, No. 18. See the NIHR Journals Library website for further project information.

Quality and safety of in-hospital care for acute medical patients at weekends: a qualitative study

BACKGROUND

The increased mortality risk associated with weekend admission to hospital (the 'weekend effect') has been reported across many health systems. More recently research has focused on causal mechanisms. Variations in the organisation and delivery of in-hospital care between weekends and weekdays have been identified, but this is not always to the detriment of weekend admissions, and the impact on mortality is uncertain. The insights of frontline staff and patients have been neglected. This article reports a qualitative study of patients and clinicians, to explore their views on quality and safety of care at weekends.

METHODS

We conducted focus groups and interviews with clinicians and patients with experience of acute medical care, recruited from three UK hospital Trusts. We analysed the data using a thematic analysis approach, aided by the use of NVivo, to explore quality and safety of care at weekends.

RESULTS

We held four focus groups and completed six in-depth interviews, with 19 clinicians and 12 patients. Four threats to quality and safety were identified as being more prominent at weekends, relating to i) the rescue and stabilisation of sick patients; ii) monitoring and responding to deterioration; iii) timely accurate management of the therapeutic pathway; iv) errors of omission and commission.

CONCLUSIONS

At weekends patients and staff are well aware of suboptimal staffing numbers, skill mix and access to resources at weekends, and identify that emergency admissions are prioritised over those already hospitalised. The consequences in terms of quality and safety and patient experience of care are undesirable. Our findings suggest the value of focusing on care processes and systems resilience over the weekends, and how these can be better supported, even in the limited resource environment that exists in many hospitals at weekends.

Biases in electronic health record data due to processes within the healthcare system: retrospective observational study

OBJECTIVE

To evaluate on a large scale, across 272 common types of laboratory tests, the impact of healthcare processes on the predictive value of electronic health record (EHR) data.

DESIGN

Retrospective observational study.

SETTING

Two large hospitals in Boston, Massachusetts, with inpatient, emergency, and ambulatory care.

PARTICIPANTS

All 669 452 patients treated at the two hospitals over one year between 2005 and 2006.

MAIN OUTCOME MEASURES

The relative predictive accuracy of each laboratory test for three year survival, using the time of the day, day of the week, and ordering frequency of the test, compared to the value of the test result.

RESULTS

The presence of a laboratory test order, regardless of any other information about the test result, has a significant association (P<0.001) with the odds of survival in 233 of 272 (86%) tests. Data about the timing of when laboratory tests were ordered were more accurate than the test results in predicting survival in 118 of 174 tests (68%).

CONCLUSIONS

Healthcare processes must be addressed and accounted for in analysis of observational health data. Without careful consideration to context, EHR data are unsuitable for many research questions. However, if explicitly modeled, the same processes that make EHR data complex can be leveraged to gain insight into patients' state of health.

"Weekend Effect" in Patients With Upper Gastrointestinal Hemorrhage: A Systematic Review and Meta-analysis

OBJECTIVES

"Weekend effect" refers to worse outcomes among patients presenting to the hospital on weekends or holidays. We performed a systematic review and meta-analysis of observational studies assessing the impact of the "weekend effect" in patients with upper gastrointestinal hemorrhage (UGIH).

METHODS

We searched key bibliographic databases using keywords and MeSH terms related to gastrointestinal hemorrhage and "weekend effect". Our primary analysis evaluated mortality in patients with UGIH who were hospitalized on the weekend or after-hours compared with a weekday. Secondary outcomes included need for definitive therapy and length of hospital stay. Relevant data were extracted and meta-analyses were performed using random effects model. Subgroup sensitivity analyses were also performed to assess the effects of key variables.

RESULTS

A total of 21 of 224 identified studies met inclusion criteria. Overall, there was no association between weekend admission and mortality among patients with UGIH (Odds Ratio (OR): 1.06; 95% confidence interval (CI): 0.99-1.14). However, meta-analysis using only the nine studies that did not report having a weekend rounder showed a significant increase in mortality (OR: 1.12; 95% CI: 1.07-1.17). There was no effect of weekend admission on any of our secondary outcomes.

CONCLUSIONS

Current evidence suggests that weekend admission is associated with significant increase in mortality in patients with non-variceal UGIH but no difference in mortality was noted in patients with variceal UGIH. Our findings are relevant to policymakers, practitioners and providers who should ensure the creation of consistent quality and access to care throughout the week.

Two-epoch cross-sectional case record review protocol comparing quality of care of hospital emergency admissions at weekends versus weekdays

INTRODUCTION

The mortality associated with weekend admission to hospital (the 'weekend effect') has for many years been attributed to deficiencies in quality of hospital care, often assumed to be due to suboptimal senior medical staffing at weekends. This protocol describes a case note review to determine whether there are differences in care quality for emergency admissions (EAs) to hospital at weekends compared with weekdays, and whether the difference has reduced over time as health policies have changed to promote 7-day services.

METHODS AND ANALYSIS

Cross-sectional two-epoch case record review of 20 acute hospital Trusts in England. Anonymised case records of 4000 EAs to hospital, 2000 at weekends and 2000 on weekdays, covering two epochs (financial years 2012-2013 and 2016-2017). Admissions will be randomly selected across the whole of each epoch from Trust electronic patient records. Following training, structured implicit case reviews will be conducted by consultants or senior registrars (senior residents) in acute medical specialities (60 case records per reviewer), and limited to the first 7 days following hospital admission. The co-primary outcomes are the weekend:weekday admission ratio of errors per case record, and a global assessment of care quality on a Likert scale. Error rates will be analysed using mixed effects logistic regression models, and care quality using ordinal regression methods. Secondary outcomes include error typology, error-related adverse events and any correlation between error rates and staffing. The data will also be used to inform a parallel health economics analysis.

ETHICS AND DISSEMINATION

The project has received ethics approval from the South West Wales Research Ethics Committee (REC): reference 13/WA/0372. Informed consent is not required for accessing anonymised patient case records from which patient identifiers had been removed. The findings will be disseminated through peer-reviewed publications in high-quality journals and through local High-intensity Specialist-Led Acute Care (HiSLAC) leads at the 121 hospitals that make up the HiSLAC Collaborative.

Multi- and univariate analyses of the weekend effect for elective lower-limb joint replacements

Introduction The weekend effect is a perceived difference in outcome between medical care provided at the weekend when compared to that of a weekday. Clearly multifactorial, this effect remains incompletely understood and variable in different clinical contexts. In this study we analyse factors relevant to the weekend effect in elective lower-limb joint replacement at a large NHS multispecialty academic healthcare centre. Materials and Methods We reviewed the electronic medical records of 352 consecutive patients who received an elective primary hip or knee arthroplasty. Patient, clinical and time-related variables were extracted from the records. The data were anonymised, then processed using a combination of uni- and multivariate statistics. Results There is a significant association between the selected weekend effect outcome measure (postoperative length of stay) and patient age, American Society of Anesthesiologists classification, time to first postoperative physiotherapy and time to postoperative radiography but not day of the week of operation. Discussion We were not able to demonstrate a weekend effect in elective lower-limb joint replacement at our institution nor identify a factor that would require additional weekend clinical medical staffing. Rather, resource priorities would seem to include measures to optimise at-risk patients preoperatively and measures to reduce time to physiotherapy and radiography postoperatively. Conclusions Our findings imply that postoperative length of stay could be minimised by strategies relating to patient selection and access to postoperative services. We have also identified a powerful statistical methodology that could be applied to other service evaluations in different clinical contexts.

A meta-analysis of weekend admission and surgery for aortic rupture and dissection

We performed a meta-analysis to determine whether weekend admission and surgery for ruptured abdominal/thoracic aortic aneurysm (RAAA/RTAA) and acute aortic dissection (AAD) is associated with increased mortality. MEDLINE and EMBASE were searched from January 1946 to December 2016 using PubMed and OVID. Eligible studies were prospective or retrospective, comparative or cohort studies enrolling patients admitting or undergoing surgery for RAAA/RTAA/AAD and reporting mortality after weekend (including holiday) versus weekday admission/surgery. Our search identified 11 studies including a total of 166,195 patients. A pooled analysis of 13 adjusted odds ratios (ORs), one adjusted hazard ratio, and one unadjusted OR from all 11 studies demonstrated a statistically significant 32% increase in mortality with weekend admission/surgery (OR, 1.32; 95% confidence interval (CI), 1.20 to 1.45; p < 0.00001). Despite possible publication bias disadvantageous to weekend admission/surgery based on funnel plot asymmetry, adjustment for the asymmetry using the trim-and-fill method did not alter the significant association of weekend admission/surgery with increased mortality (OR, 1.21; 95% CI, 1.09 to 1.34; p = 0.0006). In conclusion, weekend admission/surgery for ruptured abdominal/thoracic aortic aneurysm and acute aortic dissection (AAD) may be associated with increased mortality.

The 'weekend effect' in acute medicine: a protocol for a team-based ethnography of weekend care for medical patients in acute hospital settings

INTRODUCTION

It is now well-recognised that patients admitted to hospital on weekends are at higher risk of death than those admitted during weekdays. However, the causes of this 'weekend effect' are poorly understood. Some contend that there is a deficit of medical staff on weekends resulting in poorer quality care, whereas others find that patients admitted to hospital on weekends are sicker and therefore at higher risk of adverse outcomes. Clarifying the causal pathway is clearly important in order to identify effective solutions. In this article we describe an ethnographic approach to evaluating the organisation and delivery of medical care on weekends compared with weekdays, with a specific focus on the role of medical staff as part of National Health Service England's plan to implement 7-day services.

METHODS AND ANALYSIS

We will conduct an ethnographic study of 20 acute hospitals in England between April 2016 and March 2018 as part of the High-intensity Specialist-Led Acute Care project (www.hislac.org). Data will be collected through observations and shadowing, and interviews with staff, in 10 hospitals with higher intensity specialist (consultant) staffing on weekends and 10 with lower intensity specialist staffing. Interviews will be conducted with up to 20 patients sampled from two high-intensity and two low-intensity sites. We will coordinate, compare and contrast observations across our team of ethnographers. Analysis will be both in-depth and cross-cutting, exploring specific features within individual sites and making comparisons between them. We outline how data collection and analysis will be facilitated and organised.

ETHICS AND DISSEMINATION

The project has received ethics approval from the South West Wales Research Ethics Committee: Reference 13/WA/0372. Informed consent will be obtained for all interview participants. The findings will be disseminated through peer-reviewed publications in high-quality journals and at national and international conferences.

Management of polytrauma patients in the UK: Is there a 'weekend effect'?

BACKGROUND/PURPOSE

It has been suggested that hospital admission during weekends poses a risk for adverse outcomes and increased patient mortality, the so-called 'weekend effect'. We undertook an evaluation of the impact of weekend admissions to the management of polytraumatised patients, in a Level I Major Trauma Centre (MTC) in the UK.

MATERIALS AND METHODS

A retrospective review of prospectively documented data of polytrauma patients (injury severity score (ISS)>15), admitted between April 2013 and August 2015 was performed. Exclusion criteria included patients initially assessed in other institutions. All patients were initially managed at the emergency department (ED) according to ATLS^® principles and underwent a trauma computed tomography (CT) scan, unless requiring immediate surgical intervention.

RESULTS

During the study period 1735 patients (pts) were admitted under the care of the MTC. Four hundred and five pts were excluded as they were transferred from other institutions and 300 pts were excluded as their ISS was less than 16. Overall 1030 patients met the inclusion criteria, out of which 731 were males. Comparing the two groups (Group A: weekday admissions (670), Group B: weekend admissions (360)), there was no difference in pts gender, mechanism of injury, GCS at presentation, need for intubation and time to CT. Patients admitted over the weekend were younger (p<0.01) and presented with haemodynamic instability more frequently (p=0.02). Time to operating room was also lower during the weekend, but this did not reach statistical significance (p=0.08). Mortality was lower in Group B: 39/360 pts (10.8%) compared to Group A: 100/670 pts (14.9%) (p=0.07). The relative risk (RR) of weekend mortality was calculated as 0.726 (95% CI: 0.513-1.027).

DISCUSSION/CONCLUSION

Weekend polytrauma patients appear to be younger, more severely injured and present with a higher incidence of haemodynamic instability (shock). Overall, we failed to identify a "weekend effect" in relation to mortality, time to CT and time to operating room. On the contrary, a lower risk of mortality was noted for patents admitted during the weekend.