Variation in timely surgery for severe open tibial fractures by time and place of presentation in England from 2012 to 2019

Introduction

Several studies, using sophisticated methodologies to examine the ‘weekend effect’ or the ‘out-of-hours effect’, have found these effects to be over-simplified.¹ More nuanced analyses of temporal variations are required, such as including more detail on each day and time period of the week, and consideration of when events happened, such as the date and time of injury, as well as the date and time of hospital admission, before changing policies, such as increasing the number of health professionals working outside of ‘normal’ hours.^2-5

Radical reorganization of trauma services has recently been completed in England. Regional trauma networks (RTNs) were established in England in 2012, and they have been associated with significant improvements for trauma patients.^6,7 However, there remains wide variation in standards of care between RTNs⁸ and considerable interest in the appropriate service provision required to deliver good care.

Severe open fracture of the tibia, defined as the complex injury where the soft-tissue envelope of the lower leg is breached by a broken bone, is a unique tracer condition for trauma services organization. They can be diagnosed at the point of injury and have clear within-network bypass pathways. Current clinical guidelines require patients to be immediately transferred from the point of injury to the care of specialist orthoplastic multidisciplinary teams, usually located at a major trauma centre (MTC);^9,10 compliance with these standards is routinely recorded in the existing national audit - the Trauma Audit & Research Network (TARN).

The achievement of national standards for clinical care for severe open tibial fractures has improved for some measures particularly within MTCs.^11,12 However, these improvements have been limited to only seven of the 13 standards;¹² more than 60% of all trauma patients, especially older patients, are still treated outside of orthoplastic centres.¹³

The aim of this study was to evaluate any variability in whether patients admitted with severe open fractures of the tibia received prompt surgery, specifically debridement within 12 hours and soft-tissue coverage within 72 hours, by time and place of presentation.

Methods

Participants

All patients who were admitted to hospital with a severe open tibial fracture in England from 2012 to 2019 for whom information had been processed and de-identified by TARN up to 27 February 2020 were included in the study. We chose to use data from 2012 onwards because this is when the NHS reorganized services into regional trauma networks and MTCs, and reporting of severe open tibial fractures from MTCs to TARN was mandated. Patients with severe open fracture of the tibia were defined as those with Gustillo and Anderson grade 3B, 3C, or unknown fractures that were eligible for reporting against the Open Fracture BOAST standards that are used for the national MTC dashboard.^88,9 Duplicates arising from participants coded for the same episode at multiple hospitals were removed by TARN.

Patients for whom data were missing were excluded from the related regression analyses in a complete case analysis (Figure 1). Time to debridement was not recorded for 1,411 patients (29%) treated in MTCs, and 2,244 patients (67%) treated in ‘other’ hospitals. Time to soft-tissue coverage surgery was not recorded for 1,855 patients (38%) treated in MTCs, and 2,356 patients (71%) treated in ‘other’ hospitals, as well as those with no data on number of recorded operations (Figure 1). Overall, there was missing data for time to debridement and time to soft-tissue coverage for 45% and 52% of patients, respectively.

Fig. 1

Study inclusion and exclusion criteria for debridement and soft-tissue coverage surgery using data from the Trauma Audit Research Network for England from 2012 to 2019.

Results

The descriptive epidemiology of this cohort is presented elsewhere.¹² What follows is a brief summary of the eligible patients within this analysis (Table I). Overall, 8,258 eligible patients aged zero to 104 years sustained severe open fracture of the tibia from 2012 to 2019 and were treated in 175 different hospitals. The majority were male (63%) and the median age was 48 years (interquartile range (IQR) 29 to 67). Most participants suffered a blunt trauma injury, with the most common mechanisms being vehicle incident or collision, a fall of less than 2 m, or a fall of more than 2 m.

The proportion of participants presenting to hospital each day was similar throughout the week during Monday to Thursday (13% to 15%) with the peak occurring on Saturday (16%). Most presented during the evening (45% during 16:00 to 23:59) and few at night (16% during 00:00 to 07:59).

Over the study period, more males (68% vs 56%), and more young people aged 20 to 29 years were treated in MTCs than in other hospitals (8% vs 13%). Increasing proportions of patients were triaged to MTCs from 2012 to 2016 (43% increased to 67%) and then remained steady at about two-thirds from 2017 to 2019. Of those patients treated at ‘other’ hospitals, 93% had limb-only injuries, whereas 21% of patients treated in MTCs had more complex injuries involving other body regions. Patients treated in MTCs were likely to receive more than one operation compared with patients treated in ‘other’ hospitals (Figure 2).

Fig. 2

Number of operations had by patients with a severe open tibial fracture who were admitted to a Major Trauma Centre or other hospital in England during 2012 to 2019, as recorded in the Trauma Audit and Research Network.

The mean and median times between presentation and debridement surgery were 33.8 hours (standard deviation (SD) 233.3) and 13.6 hours (interquartile range (IQR) 6.4 to 20.9). Overall, 2,052 of all patients (46%) received surgery within 12 hours. The overall percentage of patients receiving prompt debridement surgery ranged from 28% to 62% depending on the specific day and time of the week of being admitted to hospital (Figure 3a). In MTCs, the overall percentage was also 46% (30% to 61%) compared with 44% (18% to 75%) in ‘other’ hospitals. The day and time of presentation to hospital at which the fewest patients received prompt debridement surgery was Thursday from 16:00 to 23:59.

Fig. 3

Percentage of patients with severe open tibial fracture who received timely surgery by day and time of presentation at a major trauma centre or other hospital in England from 2012 to 2019, as recorded in the Trauma Audit and Research Network. a) For debridement in 12 hours, and b) for soft-tissue coverage in 72 hours.

The multivariate regression model demonstrated that time of presentation was associated with the time to debridement surgery (Table II). Patients presenting during the day (08:00 to 15:59) were more likely to receive debridement within 12 hours (RR 1.11, 95% confidence interval (CI) 1.02 to 1.20; p = 0.011). In absolute terms, this is equivalent to a risk difference of approximately 6% compared to those admitted between 00:00 to 07:59 (adjusted absolute risk is 58.4% (day) versus 52.7% (night)). Patients presenting in the evening (16:00 to 23:59) were less likely to achieve the standard (RR 0.56, 95% CI 0.51 to 0.62; p < 0.001). In absolute terms, this is equivalent to a risk difference of approximately 23% compared to those admitted from 00:00 to 07:59 (adjusted absolute risk is 29.5% (evening) versus 52.7% (night)). Factors associated with a lower likelihood of prompt debridement surgery were being aged 30 years or more, presenting in 2018 to 2019 compared with 2012, and having a fall of less than 2 metres rather than a vehicle incident as cause (Table II). The sensitivity analysis of only those patients presenting to MTCs found identical risk factors and patterns (Supplementary Material table ii).

The mean and median times from presentation to soft-tissue coverage surgery was 100.9 hours (SD 336.8) and 47.8 hours (IQR 15.9 to 111.5). Overall, 2,187 patients (63%; 53% to 74%) received surgery within 72 hours (Figure 3b). In MTCs, the overall percentage was 64% (54% to 77%) compared with 61% (44% to 72%) in ‘other’ hospitals. The smallest proportion of patients receiving prompt soft-tissue coverage surgery were those presenting on Thursdays and Fridays.

The multivariate regression model demonstrated that day of presentation and type of hospital was associated with the time to soft-tissue coverage surgery (Table III). Patients presenting on a Thursday (RR 0.88, 95% CI 0.81 to 0.97; p = 0.010) or Friday (RR 0.89, 95% CI 0.81 to 0.98; p = 0.015) or being treated in an ‘other’ hospital regardless of day and time of presentation (RR 0.76, 95% CI 0.70 to 0.82; p < 0.001) were less likely to receive surgery within 72 hours. In absolute terms for both admission on a Thursday and Friday compared with Monday, this is equivalent to a risk difference of approximately 7% (adjusted absolute risk is 57.2% (Thursday), 57.6% (Friday) vs 64.6% (Monday)). The proportion of patients meeting the target significantly increased from 44% to 69% between 2012 and 2015. Factors associated with a lower likelihood of prompt soft-tissue coverage surgery were being aged 60 to 69 years and having more than one operation (Table III). The sensitivity analysis of the subgroup of patients presenting to MTCs found identical risk factors and patterns (Supplementary Material table iii).

Discussion

Complex patterns of variation in meeting best practice standards exist across the week and between hospitals for patients admitted with severe open tibial fracture. Time of presentation to hospital is associated with time to debridement, those patients presenting in the evening were less likely to receive timely surgery; day and type of hospital of presentation was associated with time to soft-tissue coverage, with patients admitted on Thursdays and Fridays less likely to receive timely surgery. The proportion of patients triaged to MTCs with severe open tibial fracture increased between 2012 and 2016 and then plateaued. MTCs receive more patients who are male, aged 20 to 29 years, involved in vehicle incidents, and with more complex injuries requiring more than one operation than patients admitted to ‘other hospitals.’ Typically older patients sustaining injury from falls of less than 2 m are more frequently seen in ‘other’ hospitals.

The variation in case-mix may be explained by triage tools and pathways agreed within RTNs such that more severely injured patients, or those sustaining higher energy injury mechanisms, are more likely to be triaged to MTCs. Initial debridement surgery is a core competency among orthopaedic trauma surgeons which is consistent with the finding that time rather than day of presentation is the relevant predictor for timely debridement surgery. Orthopaedic trauma surgery is delivered seven days a week in all hospitals; the key rate-limiting step is the capability of the hospital to adequately prepare the patient and service in the perioperative phase. This is not the case for soft-tissue coverage surgery, which is complex and requires combined orthoplastic surgical teams. MTCs are the de facto orthoplastic hospitals in England; it is reassuring to observe that triage to a MTC is associated with better attainment of the 72 hours standard for soft-tissue coverage and that both the flow to MTCs and achievement of the target has improved following the introduction of the RTNs. When the orthoplastic skillset is not available, either the hospital will wait for appropriate surgeons to become available or the hospital may transfer the patient. This will add differential delay between hospitals, with hospitals with lower availability of orthoplastic teams fairing worse for the outcome of interest. This may explain the finding that MTCs tended to outperform ‘other hospitals’ in the delivery of the timely soft-tissue coverage surgery. It is, however, concerning that the continuing failure of services to provide adequate orthoplastic services at weekends in MTCs, such that this standard is often missed for patients presenting towards the end of the working week.

Our findings are consistent with similar studies of patients presenting with different complex pathologies. Care quality varied across the week for patients admitted with acute stroke in England and Wales from 2013 to 2014, with four different types of temporal variation observed.³ Patients presenting with a hip fracture during 2017 in England, Wales, and Northern Ireland were significantly less likely to receive prompt surgery, within 36 hours of admission, if they were admitted during the evening (16:00 to 23:59), especially on Fridays and Saturdays.² Patients presenting at night were more likely to receive prompt surgery the following day.

This is the first-time timely surgery for patients with severe open tibial fracture has been assessed by day and time of presentation and to which type of hospital. The main strength of this study is the large population-based cohort using clinical practice data submitted from hospitals to the national audit TARN. This national audit is the means through which hospitals in England are benchmarked for trauma care; the comparative data are publicly available and used by various oversight bodies such as the Care Quality Commission²⁰ and Getting it Right First Time.²¹

We believe that our cohort is likely to be as comprehensive report of the entire population of severe open tibial fractures as possible from routinely collected national data. TARN collect data from NHS hospitals only; while independent healthcare services are provided within England, we are not aware of any such services capable of delivering the emergent and complex care required for patients with these injuries. We assess that while it is unlikely that someone suffering an open tibial fracture would not present to hospital, some hospitals may not have reported all cases.

The key limitation is of this study is the large amount of missing data, which persists even after including data from derived fields, and is differentially distributed by type of hospital. Overall, there was missing data from almost half of the available patients, and a large proportion of these patients were admitted to ‘other’ hospitals. This is consistent with the differential funding and expectation on MTCs to provide data to TARN. Also, these data were collected for audit purposes and to improve service evaluation, not to answer the research questions of this study. Interpretation of these data, which the orthoplastic community use for national benchmarking, is therefore potentially unreliable. Furthermore, the description of the patients, fractures, and treatments provided that we have been able to report is limited by the data that are available within TARN.

In conclusion, there is unwarranted variation in the delivery of key standards of care for patients presenting with severe open fracture of the tibia across the time of day and day of the week that persists even in dedicated orthoplastic hospitals. These hospitals should review their dedicated trauma theatre capacity and provision of appropriately skilled orthoplastic surgical teams. If required, this may require and increase sessional availability into evenings and across weekends.