Impact of consultant operative supervision and surgical mortality in Australia

Authors

  • Teresa Hoi Ian Wong BA (Hons),

    1. Discipline of Surgery, University of Adelaide and The Queen Elizabeth Hospital, Adelaide, South Australia, Australia
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  • Gordon Guy BA (Hons),

    1. Australian Safety and Efficacy Register of New Interventional Procedures – Surgical, Royal Australasian College of Surgeons, Adelaide, South Australia, Australia
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  • Wendy Babidge BSc, PhD,

    1. Discipline of Surgery, University of Adelaide and The Queen Elizabeth Hospital, Adelaide, South Australia, Australia
    2. Australian Safety and Efficacy Register of New Interventional Procedures – Surgical, Royal Australasian College of Surgeons, Adelaide, South Australia, Australia
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  • Guy J. Maddern MBBS, FRACS

    Corresponding author
    1. Australian Safety and Efficacy Register of New Interventional Procedures – Surgical, Royal Australasian College of Surgeons, Adelaide, South Australia, Australia
    • Discipline of Surgery, University of Adelaide and The Queen Elizabeth Hospital, Adelaide, South Australia, Australia
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  • Sources of funding: Royal Australasian College of Surgeons, Australian State Government Departments of Health and The Queen Elizabeth Hospital.

Correspondence

Professor Guy J. Maddern, Australian Safety and Efficacy Register of New Interventional Procedures – Surgical (ASERNIP-S), Royal Australasian College of Surgeons, 199 Ward Street, North Adelaide, SA 5006, Australia. Email: guy.maddern@adelaide.edu.au

Abstract

Background

In this study, the Australian and New Zealand Audit of Surgical Mortality evaluated the effect of operative supervision on certain post-operative outcomes in the surgical death subset.

Methods

This retrospective cohort study was based upon mortality data collected in 2009 which included 1673 patients who died and had surgery within 30 days of death or during the last admission. Cases were divided into three groups: consultant not supervising (group NS), consultant supervising (group S) and consultant performing the operation (group C). A comparison was done nationally and between participating states in Australia. Certain post-operative outcomes were compared between the three groups as well as between elective and emergency operations.

Results

There were significant variations in the levels of operative supervision among states in Australia. Group NS (n = 468) generally had more favourable post-operative outcomes than group S (n = 147) and group C (n = 1058), with post-operative complication rates of 24.8%, 37.4% and 40.9% for groups NS, S and C, respectively. The level of operative supervision in emergency operations was half that of elective operations. Nevertheless, the post-operative complications rate was significantly lower in emergency operations (30.6%) compared with elective operations (64.4%). The same trend was seen with clinical management deficiencies and unplanned return to theatre.

Conclusion

Operative supervision in emergency setting within Australian hospitals appears to be potentially inadequate. However, the available data suggest that unsupervised surgery did not result in worse post-operative outcomes. In appropriately selected cases, the data support surgical registrars performing surgery without consultant supervision.

Introduction

Adequate consultant supervision for surgical trainees is important to ensure quality surgical practice and patient safety. It has been suggested that the level of surgical supervision in Australia might be low.[1-3] The Australian health-care study[2] in 1995 showed that 16.6% of all hospital admissions were associated with an adverse event and half of these were surgical. Issues with knowledge-based errors and inexperience were raised, with highly preventable adverse events being more likely associated with decision making rather than procedures. Clinical errors were found in 47% of cases in the King Edward Memorial Hospital Inquiry.[3] Inadequate consultant supervision was identified as a major issue. It was suggested that appropriate supervision could have reduced adverse events.

Experience in the operating theatre is crucial for surgical trainees to develop their independence in clinical judgment and technical skills. Increased levels of consultant involvement may result in less independence and operative experience for the surgical trainees.[4] It is important to maintain the right balance between the two factors, and any teaching exercise must not compromise patients’ safety. Surgical trainees perform surgery with varying levels of consultant supervision, and sometimes independently. Many procedures are performed in Australian public hospitals without direct consultant supervision.[1] The appropriateness of the current level of operative supervision cannot be determined at present in Australia, and variation may exist between states and territories.

The aim of this research is to evaluate the effect of consultant supervision in the operating theatre on post-operative outcomes in surgical death cases and to examine any variation in the levels of consultant operative supervision among jurisdictions in Australia. This will help determine the appropriateness of the current level of operative supervision and may aid the training programme to ensure high-quality surgical practice into the future.

Methods

Inclusion criteria

All fully audited operative cases entered into the Australian and New Zealand Audit of Surgical Mortality (ANZASM) database in 2009 were included in this study. Specifically, these were patients who died and had an operation within 30 days of death or during the last hospital admission. Terminal care cases and cases still pending in the system were excluded.

Data collection

The Audits of Surgical Mortality (ASM) collect data about surgical deaths in participating hospital in all states and territories in Australia. This report only includes data from the then participating states (Western Australia, South Australia, Tasmania, Victoria, New South Wales and Queensland). The Australian Capital Territory and Northern Territory did not join the programme until 2010 and thus are excluded from this report. The detailed methodology of ANZASM is described in the ANZASM National Report 2009.[5]

In brief, ASMs are notified of deaths under the care of a consultant surgeon. A structured proforma is sent to the consultant surgeon for completion. Case details are provided on the pro forma and returned to the project office. The completed pro forma is de-identified and then assessed by a first-line assessor who is a different consultant surgeon from the same specialty. The first-line assessor, in conjunction with the project clinical director, then decides either to close the review or refer for further case review, a second-line assessment. The ANZASM subsequently identified and specified any potential clinical management incidents:

  • Area of consideration: an area of care could have been improved or different, but the issue may be debatable
  • Area of concern: an area of care should have been better
  • Adverse event: an unintended event caused by medical management rather than by the disease process, which was serious to lead to prolonged hospitalization, or temporary or permanent impairment of the patient, or which contributed to or caused death[5]

In this study, data collected by ANZASM on the level of consultant supervision in the operating theatre and certain post-operative outcomes were analysed.

Study design

This is a retrospective cohort study. Surgical deaths included in the study were divided into three groups according to the level of consultant involvement of the first operation.

  • Group NS: Consultant not present in the operating theatre during patient's operation
  • Group S: Consultant assisting or being present in the operating theatre during patient's operation
  • Group C: Consultant performing the operation

The levels of operative supervision were compared between participating states in Australia. Patient demographics, preoperative variables including co-morbidities and American Society of Anesthesiologists grade (ASA), and intra-operative variables including admission status (emergency versus elective), urgency of operation and surgical specialty were compared between the three groups.

Post-operative outcomes

The following outcomes were measured and compared between the three groups.

  • Post-operative complications: technical errors of operation (e.g. anastomotic leak, post-operative bleeding, procedure-related sepsis) and other general complications (e.g. aspiration pneumonia, sepsis, multi-organ failure)
  • Unplanned return to theatre following the initial operation
  • Unplanned intensive care unit admission
  • Unplanned readmission
  • Clinical management deficiency: area of concern and adverse event

Statistical analysis

Chi-squared test was used for comparison of categorical variables. For continuous variables, data are presented as mean ± standard deviation and compared using one-way analysis of variance. A P-value of <0.050 is considered statistically significant. Missing data were not included in the statistical analysis. All analyses were performed with VassarStats, the website for statistical computation.

Results

Out of 1767 surgical deaths that matched the inclusion criteria for this study, 94 cases (5.3%) did not have data on supervision, resulting in a total of 1673 cases that were analysed. The decision to operate was made by consultant surgeons in 1519 cases (90.8%). There were 468 (28.0%) patients in group NS, 147 (8.8%) patients in group S and 1058 (63.2%) patients in group C. Clinical management deficiencies were identified in 123 cases (7.4%).

The percentages of surgical deaths having an unsupervised operation varied across the states from 11.9% to 41.2%. Consultant performed the operation in 52.9% to 80.6% of cases (Fig. 1). The variation among participating states was statistically significant. The seniority of the primary surgeon performing the initial operation in group NS and group S is shown in Figure 2. Advanced surgical trainees operated in the largest proportion of cases. Consultant involvement in subsequent operations was increased but it was not statistically significant (Fig. 3). The surgical specialties with the highest proportion of non-supervised cases were plastic surgery (50.0%) and orthopaedic surgery (48.1%) (Fig. 4).

Figure 1.

Surgical deaths among states by level of consultant supervision in operating theatre.

Figure 2.

Seniority of the primary surgeon performing the initial operation in group NS and group S. Note: Missing data in 112 (18%) cases. AST, advanced surgical trainee; BST, basic surgical trainee; GP, general practitioner. Other* = surgical fellows, visiting consultants, radiologists and ICU consultants.

Figure 3.

Level of operative supervision of initial and subsequent operations.

Figure 4.

The proportion of group NS, S and C cases in different surgical specialties. ENT, ears, nose, throat. #Other specialties include trauma, transplant, ophthalmology and paediatric surgery.

Preoperative and intra-operative variables were compared between the three groups in Table 1. Group NS has the highest proportion of patients with emergency admission as compared with group S and group C (91.7% versus 85.7% versus 79.3%, P < 0.001). Group S and group C had a higher proportion of cases in cardiothoracic surgery and general surgery, while group NS had an increased proportion of cases in orthopaedic surgery.

Table 1. Patient variable comparison between groups
 Group NS (n = 468)Group S (n = 147)Group C (n = 1058)P-values
  1. †Other surgical specialties include trauma, transplant, ophthalmology and paediatric surgery. ASA, American Society of Anesthesiologists; ENT, ear, nose and throat.
Male gender50.2% (235)54.4% (80)57.6% (609)0.028
Mean age (±SD)75.6 (±16.8)75.7 (±15.6)72.5 (±16.8)0.001
ASA class
ASA 11.9% (9)2.7% (4)2.2% (23)0.777
ASA 26.2% (29)6.1% (9)6.8% (72)0.883
ASA 337.0% (173)23.8% (35)30.8% (326)0.007
ASA 441.0% (192)53.1% (78)47.1% (498)0.010
ASA 512.0% (56)10.9% (16)10.8% (114)0.807
Co-morbidities91.7% (429)91.2% (134)90.5% (958)0.489
Admission status
Elective7.5% (35)13.6% (20)19.8% (209)<0.001
Emergency91.7% (429)85.7% (126)79.3% (839)
Urgency of operation
Immediate (<2 h)17.7% (83)9.5% (14)18.5% (196)0.024
Emergency (<24 h)35.7% (167)34.0% (50)31.0% (328)0.191
Scheduled emergency (>24 h)35.5% (166)35.4% (52)25.6% (271)<0.001
Elective10.5% (49)21.1% (31)24.1% (255)<0.001
Surgical specialties
Cardiothoracic surgery2.8% (13)5.4% (8)7.7% (81)0.001
ENT surgery1.5% (7)0.7% (1)1.4% (15)0.896
General surgery30.8% (144)34.7% (51)48.5% (513)<0.001
Neurosurgery14.5% (68)8.8% (13)11.2% (118)0.084
Orthopaedic surgery35.5% (166)29.3% (43)12.9% (136)<0.001
Others0.2% (1)0% (0)1.7% (18)0.014
Plastic surgery2.1% (10)0.7% (1)0.9% (9)0.091
Urology3.6% (17)5.4% (8)3.3% (35)0.427
Vascular surgery9.0% (42)15.0% (22)12.6% (133)0.060

The post-operative complication rates were 24.8%, 37.4% and 40.9% for group NS, group S and group C, respectively (P < 0.001). The percentage of cases with unplanned return to theatre following the initial operation was significantly higher in groups C and S than group NS, as were the percentage of cases with clinical management deficiencies (Table 2). Post-operative complication rates were also compared among individual states. The differences between states, however, were not statistically significant.

Table 2. Post-operative outcomes between groups
 Group NS (n = 468)Group S (n = 147)Group C (n = 1058)P-values
  1. †Patients can have one or more post-operative complications. ‡Other post-operative complications were mostly general complications which included, but were not restricted to, myocardial infarction, aspiration, pneumonia, sepsis, cerebrovascular accident, pulmonary embolism, renal failure, multi-organ failure, gastrointestinal bleeding and wound dehiscence. ICU, intensive care unit.
Post-operative complications24.8% (116)37.4% (55)40.9% (433)<0.001
Specific post-operative complications
Anastomotic leak1.9% (9)2.0% (3)3.9% (41)0.103
Procedure-related sepsis3.6% (17)3.4% (5)4.8% (51)0.547
Significant post-operative bleeding1.7% (8)3.4% (5)5.9% (62)<0.001
Endoscopic perforation0% (0)0.7% (1)0.3% (3)0.251
Tissue ischaemia2.6% (12)4.1% (6)4.3% (45)0.273
Vascular graft occlusion0.6% (3)0% (0)0.8% (8)0.897
Other‡15.2% (71)26.5% (39)24.8% (262)<0.001
Unplanned return to theatre7.5% (35)12.9% (19)16.3% (172)<0.001
Unplanned ICU admission16.0% (75)17.7% (26)20.8% (220)0.101
Unplanned readmission2.8% (13)2.0% (3)4.0% (42)0.407
Clinical management deficiency3.6% (17)7.5% (11)9.0% (95)0.001

The majority of surgical deaths were cases with emergency admission (1394 cases, 84.1%) and the percentage of unsupervised operation in these cases was significantly higher compared with elective admission (30.8% versus 13.3%, P < 0.001). Patients with emergency admission were more likely to have higher ASA classes than patients with elective admission (Table 3). Yet the post-operative complication rates were 30.6% in the group of emergency admission and 64.4% in the group of elective admission (P < 0.001) (Table 3). There was more consultant involvement in the more urgent operations (Table 4).

Table 3. ASA classes, comorbidities, levels of operative supervision and post-operative outcomes by admission status
 Emergency (n = 1394)Elective (n = 264)P-values
  1. ASA, American Society of Anesthesiologists.
ASA class
ASA 11.7% (24)4.5% (12)0.008
ASA 24.7% (65)16.3% (43)<0.001
ASA 329.6% (413)44.3% (117)<0.001
ASA 448.6% (678)30.7% (81)<0.001
ASA 513.0% (181)1.9% (5)<0.001
Co-morbidities91.0% (1268)90.5% (239)0.916
Operative supervision
Group NS30.8% (429)13.3% (35)<0.001
Group S9.0% (126)7.6% (20)0.517
Group C60.2% (839)79.2% (209)<0.001
Post-operative complications30.6% (427)64.4% (170)<0.001
Unplanned return to theatre11.5% (161)24.2% (64)<0.001
Clinical management deficiency6.0% (84)14.4% (38)<0.001
Table 4. Level of operative supervision by timing of the initial operation
 Immediate (<2 h) (n = 293)Emergency (<24 h) (n = 545)Scheduled Emergency (>24 h) (n = 489)Elective (n = 335)P-values
Level of supervision
Group NS28.3% (83)30.6% (167)33.9% (166)14.6% (49)<0.001
Group S4.8% (14)9.2% (50)10.6% (52)9.3% (31)
Group C66.9% (196)60.2% (328)55.4% (271)76.1% (255)

Discussion

There was a significant variation of operative supervision in the surgical death subset among the six participating states in Australia. State 4 had the highest level of consultant involvement where consultant surgeons performed the operation in 80% of all surgical death cases and just over 10% of cases were unsupervised. State 1, in contrast, had the lowest consultant operating level of just over 50% and the highest level of unsupervised operations at around 40%.

The unsupervised group had lower rates of post-operative complication and unplanned return to theatre than the supervised group and the consultant group even though there were more emergency cases in the unsupervised group and this was consistent across the states. It is assumed that consultant surgeons would be involved in more complex operations which normally have a higher risk of post-operative complications. For instance, there was a higher proportion of cardiothoracic and general surgical cases in group C, while there was a higher proportion of plastic surgery and orthopaedic cases in group NS, perhaps reflecting the nature and general complexity of procedures in these groups.

The level of operative supervision in certain emergency admission cases appears to be less than desirable. In 30% of emergency admission cases, the patients underwent unsupervised operations. This percentage was more than double the percentage of unsupervised operations in the elective admission cases. Furthermore, the emergency admission cases had higher ASA classes as compared with the elective admission cases and thus should require more consultant involvement and supervision. Increased consultant input for emergency theatre could be a solution. However, it has to be weighed up against the risk of reducing surgical trainees’ exposure and learning opportunity. Nevertheless, the rates of post-operative complication and unplanned return to theatre were more favourable in those with an emergency admission.

In this study, most surgical deaths were caused by the underlying disease processes alone and were treated appropriately. Clinical management deficiencies were only demonstrated in 7% of all cases. Most patients who died were in the extreme of age and had multiple co-morbidities which increased the risk of death.

The operation decision was made by a consultant in over 90% of cases. This shows that most cases had consultant input in decision making. The favourable outcome in non-supervised operations may reflect that consultant surgeons had selected appropriate cases for surgical registrars and had made excellent assessment of their operative ability. Complex cases should normally be supervised. Consultant surgeons are able to judge if a registrar is capable of performing surgery safely. They can offer help in the operating theatre if requested. Surgical registrars should learn to identify situations where help from senior staff is needed. This perhaps could be reflected by the fact that urgent emergency operations had more consultant involvement than scheduled emergency operations.

The level of surgical supervision did not significantly increase in subsequent operations and this is considered as less than satisfactory. Advanced surgical trainees were the primary surgeons in the majority of non-consultant operations, supervised or unsupervised by consultants, which is appropriate. However, service registrars, registrars in non-training position, operated on 13% of cases unsupervised and this should be reduced to zero.

Comparison with other studies

Extensive studies have been conducted to determine whether the levels of surgical supervision could affect patient outcomes. Itani et al.[4] compared the 30-day mortality and morbidity rates in 610 660 surgical patients having surgery performed under different levels of consultant supervision in the operating theatre from 1998 to 2004. It was found that the level of supervision did not significantly affect the stated clinical outcome. They included all patients having surgery during the study period while we only had patients limited to the surgical death subset in our study. Itani et al.[4] also showed an increasing level of senior supervision over the study period. Despite this, there was no difference in the odds ratios of the adjusted mortality and morbidities. On the other hand, the Scottish Audit of Surgical Mortality reported an increased level of consultant input from 1994 to 2003 while there was a decrease in adverse events which contributed to or caused death during this period.[6]

A number of studies looking at seniority of surgeons on specific types of surgery have been conducted. Borowski et al.[7] found no difference in technical operative errors and mortality between unsupervised trainees, supervised trainees and consultants performing operations on colorectal cancer patients when case-mix adjustment was applied. They suggested there was an under-utilized training opportunity for surgical trainees. Robson et al.[8] found no difference in recurrence rates following inguinal hernia repair performed by senior trainees, supervised junior trainees and consultants. However, the recurrence rate was significantly higher for unsupervised junior trainees. Other studies on specific surgeries, including thyroid, cardiac and pelvic floor surgeries, also had similar conclusion.[9-14] Palm et al.[15] showed that operations on technically demanding proximal femur fracture performed by unsupervised junior trainees had a significantly higher risk for re-operation while there was no difference for operations on uncomplicated proximal femur fracture, confirming that junior trainees should not operate on complex cases without supervision.

In our study, it was found that patients with emergency admission were more likely to have unsupervised operations and this is comparable with other studies.[4, 7, 10, 13, 16] Despite this, outcomes did not appear to be worse for unsupervised cases in this cohort. Our study is comparable with the Western Australian Audit of Surgical Mortality in 2004 which revealed a twofold increase in the proportion of deaths with deficiency of care in the elective cases over the emergency cases.[16]

Limitations of study and future direction

There are several limitations in this study. The study was based on a small subset of operative cases, that is, those with surgical deaths. The full extent of operative supervision and post-operative outcomes for all patients having surgery during the study period could not be analysed and compared. Hence, the findings in this study cannot apply to all surgery, and further studies including surgical patients who survive may be required to confirm the conclusion. Also, the comparison made between groups in this study could not be risk adjusted. For instance, complexity and difficulty of the operations could not be determined. Although ASA class is a good physiological indicator of physical health before surgery, it cannot be used to deduce the complexity or expected outcome of the operations. The evaluation was limited to supervision in the operating theatre. Supervision in other aspects of surgery such as post-operative care, which is important to patient post-operative outcome, was not considered in our study. The data in this report are limited to the year 2009 only, so over time, increasing data will result in more power to the study. There was missing data in the pro forma, especially with seniority detail. Eighteen per cent of cases in one state did not have data on seniority.

Conclusion

Within the surgical death subset in 2009, there were significant variations among states in Australia in the levels of consultant supervision in the operating theatre. It was also concluded that operative supervision in the emergency setting was, in some cases, inadequate. However, within the same subset, surgery performed without consultant surgeon supervision in the operating theatre did not result in worse post-operative outcomes in terms of post-operative complications, unplanned return to theatre and clinical management deficiency. This should reassure patients and administrators that, in appropriately selected cases, it is safe to have surgery performed by unsupervised surgical registrars.

Acknowledgements

The authors would like to thank the following:

Mr James Aitken, Western Australian Audit of Surgical Mortality

Dr John Field, PhD AStat, Statistical Support Service, University of Adelaide Faculty of Health Sciences & Basil Hetzel Institute, The Queen Elizabeth Hospital

Ms Claudia Retegan, ANZASM Regional project manager, Victorian Audit of Surgical Mortality

Dr Kenneth Lang, ANZASM Regional project manager, South Australian Audit of Peri-operative Mortality

Dr Diana Azzam, ANZASM Regional project manager, Western Australian Audit of Surgical Mortality

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