Comparison of UK paediatric cardiac surgical performance by analysis of routinely collected data 1984-96: was Bristol an outlier?

Effect of procedural volume on the outcomes of congenital heart surgery in Japan

OBJECTIVES

The present study developed a new risk model for congenital heart surgery in Japan and determined the relationship between hospital procedural volume and mortality using the developed model.

METHODS

We analyzed 47,164 operations performed between 2013 and 2018 registered in the Japan Cardiovascular Surgery Database-Congenital and created a new risk model to predict the 90-day/in-hospital mortality using the Japanese congenital heart surgery mortality categories and patient characteristics. The observed/expected ratios of mortality were compared among 4 groups based on annual hospital procedural volume (group A [5539 procedures performed in 90 hospitals]: ≤50, group B [9322 procedures in 24 hospitals]: 51-100, group C [13,331 procedures in 21 hospitals]: 101-150, group D [18,972 procedures in 15 hospitals]: ≥151).

RESULTS

The overall mortality rate was 2.64%. The new risk model using the surgical mortality category, age-weight categories, urgency, and preoperative mechanical ventilation and inotropic use achieved a c-index of 0.81. The observed/expected ratios based on the new risk model were 1.37 (95% confidence interval, 1.18-1.58), 1.21 (1.08-1.33), 1.04 (0.94-1.14), and 0.78 (0.71-0.86) in groups A, B, C, and D, respectively. In the per-procedure analysis, the observed/expected ratios of the Rastelli, coarctation complex repair, and arterial switch procedures in group A were all more than 3.0.

CONCLUSIONS

The risk-adjusted mortality rate for low-volume hospitals was high for not only high-risk but also medium-risk procedures. Although the overall mortality rate for congenital heart surgeries is low in Japan, the observed volume-mortality relationship suggests potential for improvement in surgical outcomes.

Epidemiology of Surgical Procedures, Anesthesia, and Imaging Studies by Gestational Age during the First Year of Life in Medicaid-Insured Infants

OBJECTIVES

To evaluate the rate of surgical procedures, anesthetic use, and imaging studies by prematurity status for the first year of life we analyzed data for Texas Medicaid-insured newborns.

STUDY DESIGN

We developed a retrospective population-based live birth cohort of newborn infants insured by Texas Medicaid in 2010-2014 with 4 subcohorts: extremely premature, very premature, moderate/late premature, and term.

RESULTS

In 1 102 958 infants, surgical procedures per 100 infants were 135.9 for extremely premature, 35.4 for very premature, 15.5 for moderate/late premature, and 6.5 for term. Anesthetic use was 62.0 for extremely premature, 20.8 for very premature, 11.1 for moderate/late premature, and 5.6 for the term subcohort. The most common procedures in the extremely premature were neurosurgery, intubations, and procedures that facilitated caloric intake (gastrostomy tubes and fundoplications). The annual rates for the first year of life for chest radiograph ranged from 15.0 per year for the extremely premature cohort to 0.6 for term infants and for magnetic resonance imaging (MRI) from 0.3 to 0.01. MRI was the most common imaging study with anesthesia support in all maturity levels. MRIs were done in extremely premature without anesthesia in over 90% and in term infants in 57.2%.

CONCLUSIONS

Surgical procedures, anesthetic use, and imaging studies in infants are common and more frequent with higher a degree of prematurity while the use of anesthesia is lower in more premature newborns. These findings can provide direction for outcome studies of surgery and anesthesia exposure.

Laparoscopic Colorectal Surgery Outcomes Improved After National Training Program (LAPCO) for Specialists in England

OBJECTIVE

To examine the impact of The National Training Program for Lapco on the rate of laparoscopic surgery and clinical outcomes of cases performed by Lapco surgeons after completion of training.

SUMMARY OF BACKGROUND DATA

Lapco provided competency-based supervised clinical training for specialist colorectal surgeons in England.

METHODS

We compared the rate of laparoscopic surgery, mortality, and morbidity for colorectal cancer resections by Lapco delegates and non-Lapco surgeons in 3-year periods preceding and following Lapco using difference in differences analysis. The changes in the rate of post-Lapco laparoscopic surgery with the Lapco sign-off competency assessment and in-training global assessment scores were examined using risk-adjusted cumulative sum to determine their predictive clinical validity with predefined competent scores of 3 and 5 respectively.

RESULTS

One hundred eight Lapco delegates performed 4586 elective colo-rectal resections pre-Lapco and 5115 post-Lapco while non-Lapco surgeons performed 72,930 matched cases. Lapco delegates had a 37.8% increase in laparoscopic surgery which was greater than non-Lapco surgeons by 20.9% [95% confidence interval (CI), 18.5-23.3, P < 0.001) with a relative decrease in 30-day mortality by -1.6% (95% CI, -3.4 to -0.2, P = 0.039) and 90-day mortality by -2.3% (95% CI, -4.3 to -0.4, P = 0.018). The change point of risk-adjusted cumulative sum was 3.12 for competency assessment tool and 4.74 for global assessment score whereas laparoscopic rate increased from 44% to 66% and 40% to 56%, respectively.

CONCLUSIONS

Lapco increased the rate of laparoscopic colorectal cancer surgery and reduced mortality and morbidity in England. In-training competency assessment tools predicted clinical performance after training.

Days at Home after Surgery: An Integrated and Efficient Outcome Measure for Clinical Trials and Quality Assurance

BACKGROUND

Surgical audit, sometimes including public reporting, is an important foundation of high quality health care. We aimed to assess the validity of a novel outcome metric, days at home up to 30 days after surgery, as a surgical outcome measure in clinical trials and quality assurance.

METHODS

This was a multicentre, registry-based cohort study. We used prospectively collected hospital and national healthcare registry data obtained from patients aged 18 years or older undergoing a broad range of surgeries in Sweden over a 10-year period. The association between days at home up to 30 days after surgery and patient (older age, poorer physical status, comorbidity) and surgical (elective or non-elective, complexity, duration) risk factors, process of care outcomes (re-admissions, discharge destination), clinical outcomes (major complications, 30-day mortality) and death up to 1 year after surgery were measured.

FINDINGS

From January, 2005, to December, 2014, we obtained demographic and perioperative data on 636,885 patients from 21 Swedish hospitals. Mortality at 30 days and one year was 1.8% and 7.3%, respectively. The median (IQR) days at home up to 30 days after surgery was 27 (23-29), being significantly lower among high-risk patients, those recovering from more complex surgical procedures, and suffering serious postoperative complications (all p < 0.0001). Patients with 8 days or less at home up to 30 days after surgery had a nearly 7-fold higher risk of death up to 1 year postoperatively when compared with those with 29 or 30 days at home (adjusted HR 6.78 [95% CI: 6.44-7.13]).

INTERPRETATION

Days at home up to 30 days after surgery is a valid, easy to measure patient-centred outcome metric. It is highly sensitive to changes in surgical risk and impact of complications, and has prognostic importance; it is therefore a valuable endpoint for perioperative clinical trials and quality assurance.

FUNDING

Swedish National Research Council Medicine and Stockholm County Council ALF-project grant (LE), and the Australian National Health and Medical Research Council (PM).

Trends, patterns and predictive factors of infant and child mortality in well-performing and underperforming states of India: a secondary analysis using National Family Health Surveys

OBJECTIVES

This paper analyses the patterns and trends in the mortality rates of infants and children under the age of 5 in India (1992-2016) and quantifies the variation in performance between different geographical states through three rounds of nationally representative household surveys.

DESIGN

Three rounds of cross-sectional survey data.

SETTING

The study is conducted at the national level: India and its selected good-performing states, namely Haryana, Kerala, Maharashtra, Punjab and Tamil Nadu, and selected poor-performing states, namely Bihar, Chhattisgarh, Madhya Pradesh and Uttar Pradesh.

PARTICIPANTS

Adopting a multistage, stratified random sampling, 601 509 households with 699 686 women aged 15-49 years in 2015-2016, 109 041 households with 124 385 women aged 15-49 years in 2005-2006, and 88 562 households with 89 777 ever married women in the age group 13-49 years in 1992-1993 were selected.

RESULTS

Through the use of maps, this paper clearly shows that the overall trend in infant and child mortality is on a decline in India. Computation of relative change shows that majority of the states have witnessed over 50% reduction in both infant and under-5 mortality rates from National Family Health Survey (NFHS)-I to NFHS-4. However, the improvements are not evenly distributed, and there is huge variation in performance between states over time. Funnel plots show that the most populous states like Uttar Pradesh Bihar and Madhya Pradesh have underperformed consistently across the survey period from 1992 to 2016. Regression analysis comparing high-performing and low-performing states revealed that female infants and women with shorter birth intervals had greater risk of infant deaths in poor-performing states.

CONCLUSION

Attempts to reduce infant and child mortality rates in India are heading in the right direction. Even so, there is huge variation in performance between states. This paper recommends a mix of strategies that reduce child and infant mortality among the high-impact states where the biggest improvements can be expected, including the need to address neonatal mortality.

Outcome-based Clinical Indicators for Intensive Care Medicine

The clinical indicator is a tool used to monitor the quality of health care. Its use in the Intensive Care Unit (ICU) is desirable for many reasons: the maintenance of minimum standards, the development of best practice and the delivery of cost-effective health care. The utility of clinical indicators in ICU is limited by the lack of universal, robust, transparent, evidence-based and risk-adjusted measures of quality, and the difficulties in defining “quality care” and “good outcome”. Monitoring of adverse events, system descriptors, and resource indicators is valuable but they have a limited relationship to the quality of care. ICU mortality prediction models provide a global measure of quality and, despite their inherent deficiencies, remain one of the most robust and useful clinical indicators.

Investigating the association of alerts from a national mortality surveillance system with subsequent hospital mortality in England: an interrupted time series analysis

Objective

To investigate the association between alerts from a national hospital mortality surveillance system and subsequent trends in relative risk of mortality.

Background

There is increasing interest in performance monitoring in the NHS. Since 2007, Imperial College London has generated monthly mortality alerts, based on statistical process control charts and using routinely collected hospital administrative data, for all English acute NHS hospital trusts. The impact of this system has not yet been studied.

Methods

We investigated alerts sent to Acute National Health Service hospital trusts in England in 2011–2013. We examined risk-adjusted mortality (relative risk) for all monitored diagnosis and procedure groups at a hospital trust level for 12 months prior to an alert and 23 months post alert. We used an interrupted time series design with a 9-month lag to estimate a trend prior to a mortality alert and the change in trend after, using generalised estimating equations.

Results

On average there was a 5% monthly increase in relative risk of mortality during the 12 months prior to an alert (95% CI 4% to 5%). Mortality risk fell, on average by 61% (95% CI 56% to 65%), during the 9-month period immediately following an alert, then levelled to a slow decline, reaching on average the level of expected mortality within 18 months of the alert.

Conclusions

Our results suggest an association between an alert notification and a reduction in the risk of mortality, although with less lag time than expected. It is difficult to determine any causal association. A proportion of alerts may be triggered by random variation alone and subsequent falls could simply reflect regression to the mean. Findings could also indicate that some hospitals are monitoring their own mortality statistics or other performance information, taking action prior to alert notification.

Evaluation of a national surveillance system for mortality alerts: a mixed-methods study

Background

Since 2007, Imperial College London has generated monthly mortality alerts, based on statistical process control charts and using routinely collected hospital administrative data, for all English acute NHS hospital trusts. The impact of this system has not yet been studied.

Objectives

To improve understanding of mortality alerts and evaluate their impact as an intervention to reduce mortality.

Design

Mixed methods.

Setting

English NHS acute hospital trusts.

Participants

Eleven trusts were included in the case study. The survey involved 78 alerting trusts.

Main outcome measures

Relative risk of mortality and perceived efficacy of the alerting system.

Data sources

Hospital Episodes Statistics, published indicators on quality and safety, Care Quality Commission (CQC) reports, interviews and documentary evidence from case studies, and a national evaluative survey.

Methods

Descriptive analysis of alerts; association with other measures of quality; associated change in mortality using an interrupted time series approach; in-depth qualitative case studies of institutional response to alerts; and a national cross-sectional evaluative survey administered to describe the organisational structure for mortality governance and perceptions of efficacy of alerts.

Results

A total of 690 mortality alerts generated between April 2007 and December 2014. CQC pursued 75% (154/206) of alerts sent between 2011 and 2013. Patient care was cited as a factor in 70% of all investigations and in 89% of sepsis alerts. Alerts were associated with indicators on bed occupancy, hospital mortality, staffing, financial status, and patient and trainee satisfaction. On average, the risk of death fell by 58% during the 9-month lag following an alert, levelling afterwards and reaching an expected risk within 18 months of the alert. Acute myocardial infarction (AMI) and sepsis alerts instigated institutional responses across all the case study sites, although most sites were undertaking some parallel activities at a more general level to address known problems in care in these and other areas. Responses included case note review and coding improvements, changes in patient pathways, changes in diagnosis of sepsis and AMI, staff training in case note write-up and coding, greater transparency in patient deterioration, and infrastructure changes. Survey data revealed that 86% of responding trusts had a dedicated trust-level lead for mortality reduction and 92% had a dedicated trust-level mortality group or committee in place. Trusts reported that mortality reduction was a high priority and that there was strong senior leadership support for mortality monitoring. The weakest areas reported concerned the accuracy of coding, the quality of specialty-level mortality data and understanding trends in specialty-level mortality data.

Limitations

Owing to the correlational nature of our analysis, we could not ascribe a causal link between mortality alerts and reductions in mortality. The complexity of the institutional context and behaviour hindered our capacity to attribute locally reported changes specifically to the effects of the alerts rather than to ongoing institutional strategy.

Conclusions

The mortality alert surveillance system reflects aspects of quality care and is valued by trusts. Alerts were considered a useful focus for identifying problems and implementing interventions around mortality.

Future work

A further analysis of site visits and survey material, the application of evaluative framework to other interventions, a blinded case note review and the dissemination of findings.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Variable life adjusted display methodology for continuous performance monitoring of carotid endarterectomy

Introduction The aim of this study was to use variable life-adjusted display (VLAD) methodology to monitor performance of six vascular surgeons undertaking carotid endarterectomy in a single institution. Materials and methods This was a prospective study with continuous analysis. A risk score model to predict 30-day stroke or death for individual patients was developed from data collected from 839 patients from 1992 to 1999. The model was used to monitor performance of six surgeons from 2000 to 2009. Individual risk factors and 30-day outcomes were analysed and VLAD plots were created for the whole unit and for each surgeon. Results Among the 941 carotid endarterectomies in the performance analysis, 28 adverse events were recorded, giving an overall stroke or death rate of 3.06%. The risk model predicted there would be 33 adverse events. There was no statistical difference between the predicted and the observed adverse events (P > 0.2, χ2 value 1.25, 4 degrees of freedom). The VLAD plot for the whole unit shows an overall net gain in operative performance, although this could have been chance variation. The individual VLAD plot showed that surgeons 1, 2, 3 and 6 to have an overall net gain in the number of successful operations. The changes observed between the surgeons was not significant (P > 0.05) suggesting chance variation only. Conclusions Performance of carotid endarterectomy can be continuously assessed using VLAD methodology for units and individual surgeons. Early identification and correction of performance variation could facilitate improved quality of care.

Variation in neonatal mortality and its relation to country characteristics in sub-Saharan Africa: an ecological study

BACKGROUND

A substantial reduction in neonatal mortality is the main priority to reduce under-five mortality. A clear understanding of the variation in neonatal mortality and the underlying causes is important for targeted intervention. We aimed to explore variation in neonatal mortality and identify underlying causes of variation in neonatal mortality in sub-Saharan Africa (SSA).

METHODS

This ecological study used 2012 publicly available data from WHO, the US Agency for International Development and the World Bank. Variation in neonatal mortality across 49 SSA countries was examined using control chart and explanatory spatial data analysis. Associations between country-level characteristics and neonatal mortality were examined using linear regression analysis.

RESULTS

The control chart showed that 28 (57%) SSA countries exhibited special-cause variation, 14 countries were below and 14 above the 99.8% control-limits. The remaining 21 (43%) SSA countries showed common-cause variation. No spatial clustering was observed for neonatal mortality (Global Moran's I statistic -0.10; p=0.74). Linear regression analysis showed HIV/AIDS prevalence among the population of reproductive age to be positively associated with neonatal mortality (β=0.463; 95% CI 0.135 to 0.790; p<0.01). Declining socioeconomic deprivation (β=-0.234; 95% CI -0.424 to -0.044; p<0.05) and high quality of healthcare governance (β=-1.327, 95% CI -2.073 to -0.580; p<0.01) were inversely associated with neonatal mortality.

CONCLUSION

This study shows a wide variation in neonatal mortality in SSA. A substantial part of this variation can be explained by differences in the quality of healthcare governance, prevalence of HIV and socioeconomic deprivation. Future studies should validate our findings using more rigorous epidemiological study designs.

Improving risk adjustment in the PRAiS (Partial Risk Adjustment in Surgery) model for mortality after paediatric cardiac surgery and improving public understanding of its use in monitoring outcomes

Background

In 2011, we developed a risk model for 30-day mortality after children’s heart surgery. The PRAiS (Partial Risk Adjustment in Surgery) model uses data on the procedure performed, diagnosis, age, weight and comorbidity. Our treatment of comorbidity was simplistic because of data quality. Software that implements PRAiS is used by the National Congenital Heart Disease Audit (NCHDA) in its audit work. The use of PRAiS triggered the temporary suspension of surgery at one unit in 2013. The public anger that surrounded this illustrated the need for public resources around outcomes monitoring.

Objectives

(1) To improve the PRAiS risk model by incorporating more information about comorbidities. (2) To develop online resources for the public to help them to understand published mortality data.

Design

Objective 1 The outcome measure was death within 30 days of the start of each surgical episode of care. The analysts worked with an expert panel of clinical and data management representatives. Model development followed an iterative process of clinical discussion of risk factors, development of regression models and assessment of model performance under cross-validation. Performance was measured using the area under the receiving operator characteristic (AUROC) curve and calibration in the cross-validation test sets. The final model was further assessed in a 2014–15 validation data set.Objective 2 We developed draft website material that we iteratively tested through four sets of two workshops (one workshop for parents of children who had undergone heart surgery and one workshop for other interested users). Each workshop recruited new participants. The academic psychologists ran two sets of three experiments to explore further understanding of the web content.

Data

We used pseudonymised NCHDA data from April 2009 to April 2014. We later unexpectedly received a further year of data (2014–15), which became a prospective validation set.

Results

Objective 1The cleaned 2009–14 data comprised 21,838 30-day surgical episodes, with 539 deaths. The 2014–15 data contained 4207 episodes, with 97 deaths. The final regression model included four new comorbidity groupings. Under cross-validation, the model had a median AUROC curve of 0.83 (total range 0.82 to 0.83), a median calibration slope of 0.92 (total range 0.64 to 1.25) and a median intercept of –0.23 (range –1.08 to 0.85). In the validation set, the AUROC curve was 0.86 [95% confidence interval (CI) 0.83 to 0.89], and its calibration slope and intercept were 1.01 (95% CI 0.83 to 1.18) and 0.11 (95% CI –0.45 to 0.67), respectively. We recalibrated the final model on 2009–15 data and updated the PRAiS software.Objective 2We coproduced a website (http://childrensheartsurgery.info/) that provides interactive exploration of the data, two animations and background information. It was launched in June 2016 and was very well received.

Limitations

We needed to use discharge status as a proxy for 30-day life status for the 14% of overseas patients without a NHS number. We did not have sufficient time or resources to extensively test the usability and take-up of the website following its launch.

Conclusions

The project successfully achieved its stated aims. A key theme throughout has been the importance of collaboration and coproduction. In particular for aim 2, we generated a great deal of generalisable learning about how to communicate complex clinical and mathematical information.

Further work

Extending our codevelopment approach to cover many other aspects of quality measurement across congenital heart disease and other specialised NHS services.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Selection by a panel of clinicians and family representatives of important early morbidities associated with paediatric cardiac surgery suitable for routine monitoring using the nominal group technique and a robust voting process

OBJECTIVE

With survival following paediatric cardiac surgery improving, the attention of quality assurance and improvement initiatives is shifting to long-term outcomes and early surgical morbidities. We wanted to involve family representatives and a range of clinicians in selecting the morbidities to be measured in a major UK study.

SETTING

Paediatric cardiac surgery services in the UK.

PARTICIPANTS

We convened a panel comprising family representatives, paediatricians from referring centres, and surgeons and other clinicians from surgical centres.

PRIMARY AND SECONDARY OUTCOME MEASURES

Using the nominal group technique augmented by a robust voting process to identify group preferences, suggestions for candidate morbidities were elicited, discussed, ranked and then shortlisted. The shortlist was passed to a clinical group that provided a view on the feasibility of monitoring each shortlisted morbidity in routine practice. The panel then met again to select a prioritised list of morbidities for further study, with the list finalised by the clinical group and chief investigators.

RESULTS

At the first panel meeting, 66 initial suggestions were made, with this reduced to a shortlist of 24 after two rounds of discussion, consolidation and voting. At the second meeting, this shortlist was reduced to 10 candidate morbidities. Two were dropped on grounds of feasibility and replaced by another the panel considered important. The final list of nine morbidities included indicators of organ damage, acute events and feeding problems. Family representatives and clinicians from outside tertiary centres brought some issues to greater prominence than if the panel had consisted solely of tertiary clinicians or study investigators.

CONCLUSION

The inclusion of patient and family perspectives in identifying metrics for use in monitoring a specialised clinical service is challenging but feasible and can broaden notions of quality and how to measure it.

Identifying improvements to complex pathways: evidence synthesis and stakeholder engagement in infant congenital heart disease

OBJECTIVES

Many infants die in the year following discharge from hospital after surgical or catheter intervention for congenital heart disease (3-5% of discharged infants). There is considerable variability in the provision of care and support in this period, and some families experience barriers to care. We aimed to identify ways to improve discharge and postdischarge care for this patient group.

DESIGN

A systematic evidence synthesis aligned with a process of eliciting the perspectives of families and professionals from community, primary, secondary and tertiary care.

SETTING

UK.

RESULTS

A set of evidence-informed recommendations for improving the discharge and postdischarge care of infants following intervention for congenital heart disease was produced. These address known challenges with current care processes and, recognising current resource constraints, are targeted at patient groups based on the number of patients affected and the level and nature of their risk of adverse 1-year outcome. The recommendations include: structured discharge documentation, discharging certain high-risk patients via their local hospital, enhanced surveillance for patients with certain (high-risk) cardiac diagnoses and an early warning tool for parents and community health professionals.

CONCLUSIONS

Our recommendations set out a comprehensive, system-wide approach for improving discharge and postdischarge services. This approach could be used to address challenges in delivering care for other patient populations that can fall through gaps between sectors and organisations.

Trends in 30-day mortality rate and case mix for paediatric cardiac surgery in the UK between 2000 and 2010

Objectives

To explore changes over time in the 30-day mortality rate for paediatric cardiac surgery and to understand the role of attendant changes in the case mix.

Methods, setting and participants

Included were: all mandatory submissions to the National Institute of Cardiovascular Outcomes Research (NICOR) relating to UK cardiac surgery in patients aged <16 years. The χ² test for trend was used to retrospectively analyse the proportion of surgical episodes ending in 30-day mortality and with various case mix indicators, in 10 consecutive time periods, from 2000 to 2010. Comparisons were made between two 5-year eras of: 30-day mortality, period prevalence and mean age for 30 groups of specific operations.

Main outcome measure

30-day mortality for an episode of surgical management.

Results

Our analysis includes 36 641 surgical episodes with an increase from 2283 episodes in 2000 to 3939 in 2009 (p<0.01). The raw national 30-day mortality rate fell over the period of review from 4.3% (95% CI 3.5% to 5.1%) in 2000 to 2.6% (95% CI 2.2% to 3.0%) in 2009/2010 (p<0.01). The case mix became more complex in terms of the percentage of patients <2.5 kg (p=0.05), with functionally univentricular hearts (p<0.01) and higher risk diagnoses (p<0.01). In the later time era, there was significant improvement in 30-day mortality for arterial switch with ventricular septal defect (VSD) repair, patent ductus arteriosus ligation, Fontan-type operation, tetralogy of Fallot and VSD repair, and the mean age of patients fell for a range of operations performed in infancy.

Conclusions

The raw 30-day mortality rate for paediatric cardiac surgery fell over a decade despite a rise in the national case mix complexity, and compares well with international benchmarks. Definitive repair is now more likely at a younger age for selected infants with congenital heart defects.

Mortality as a measure of quality of care in infants with congenital cardiovascular malformations following surgery

INTRODUCTION

Mortality has traditionally been perceived as a straightforward measure of outcome and has been used to evaluate surgical performance. In the rapidly developing arena of paediatric cardiac surgery, the insightful analysis of mortality figures is challenging.

SOURCES OF DATA

This report discusses the issues involved when mortality is used as a marker for surgical outcome, referring to national and international audit and research data.

AREAS OF AGREEMENT

Mortality is an important variable and should be transparently defined, reported and monitored.

AREAS OF CONTROVERSY

Definitions of mortality, assessments of risk and interpretations of reported statistics all have limitations that must be recognized.

GROWING POINTS

Traditional use of raw early mortality as a simplistic indicator of outcome and performance is evolving to include risk-adjusted mortality, longer-term survival, reinterventions and complications.

AREAS TIMELY FOR DEVELOPING RESEARCH

As the vast majority of children undergoing cardiac surgery now survive beyond 30 days, the focus for measures of quality is shifting towards morbidity.

A toxic triangle of destructive leadership at Bristol Royal Infirmary: A study of organizational Munchausen syndrome by proxy

Although leadership literature increasingly recognizes that leadership is a complex, co-creational process among leaders, followers, and context, destructive leadership scholarship has only recently embraced this paradigm. This article contributes to the toxic triangle debate by linking destructive leadership theory and disaster research in a case study of Bristol Royal Infirmary, a UK hospital that experienced a crisis in its pediatric cardiology unit resulting in the death of dozens of babies undergoing surgery. Thus, the article expands the literature on organizational failure by offering an assessment of how seemingly good, well-intentioned professionals can nonetheless create destructive leadership dynamics and proposes a new, more nuanced theoretical framework called organizational Munchausen syndrome by proxy as a way to analyze what went wrong.

Intersurgeon variability in long-term outcomes after transatrial repair of tetralogy of Fallot: 25 years' experience with 675 patients

OBJECTIVE

To compare the long-term reoperation rates among surgeons performing transatrial repair of tetralogy of Fallot.

METHODS

The data set of 675 patients undergoing transatrial repair of tetralogy of Fallot at 1 institution from 1980 to 2005 was analyzed for intersurgeon differences in the reoperation rates.

RESULTS

A follow-up period >15 years was available for 5 surgeons, allowing for comparison (541 patients; >80 patients/surgeon). The reintervention rate at 10 years varied from 8.8% (95% confidence interval [CI], 5.3%-14.5%) to 26.7% (95% CI, 14.9%-44.9%; hazard ratio, 3.4; P = .001). The procedures of 1 surgeon resulted in a reoperation rate of 10.5% at 20 years (95% CI, 5.4%-25.3%). The type of reoperation required varied among the surgeons. One surgeon had had no reoperations for pulmonary artery stenosis. Of the 5 surgeons, 2 (surgeons 2 and 5) had equivalent overall 10-year reoperation rates (24.1%, 95% CI, 12.9%-42.3%; vs 26.7%, 95% CI, 14.9%-44.9%; P = .32). Surgeon 5 had reoperation almost exclusively for right ventricular outflow tract obstruction (20.6%; 95% CI, 12.4%-33.1%) and surgeon 2 for right ventricular dilation (17.4%; 95% CI, 7.8%-36.3%). None of the patients treated by surgeon 5 required implantation of a valved conduit.

CONCLUSIONS

An analysis of the reoperation rate during the long-term follow-up of transatrial repair of tetralogy of Fallot identified variability in the outcomes among 5 surgeons. The analysis of these differences suggested that an optimal amount of opening of the right ventricular outflow tract can lead to a decreased reintervention rate. The analysis of intersurgeon variability in outcomes should be encouraged, because it will lead to improvements in cardiac surgery outcomes.

A mortality risk model to adjust for case mix in UK paediatric cardiac surgery

Background

Congenital heart disease (CHD) is a relatively common disorder in childhood, affecting approximately 8–9 per 1000 live-born infants annually in the UK. CHD often involves serious abnormalities and is an important cause of childhood mortality, morbidity and disability. It is generally recognised that it is important and valuable to monitor outcomes in cardiac surgery and that, to do so fairly and effectively, one needs to risk stratify the case load of each unit. There is evidence that, since outcome monitoring in adult cardiac surgery became mandatory and routine, outcomes have improved. At present, no process for routinely monitoring risk-adjusted outcomes in paediatric cardiac surgery exists.

Objectives

To establish whether or not a risk model can be developed that is fit for the purpose of adjusting for case mix severity to facilitate routine monitoring of outcomes for paediatric cardiac surgery in the UK and to assess whether or not and how diagnostic information can augment procedural information in risk adjustment.

Methods

Data from the Central Cardiac Audit Database (CCAD) for all cardiac surgery procedures, excluding reoperations within 30 days, performed in the UK for patients < 16 years between 2000 and 2010 (38,597 patient episodes) were included: 70% for model development and 30% quarantined for validation. The outcome was 30-day survival, as supplied to CCAD through the Central Register of NHS patients (now the Medical Research Information Service). The CCAD defines 36 ‘specific procedures’. Nine of these were merged as a ‘low-volume specific procedure’ group (< 90 cases each in the entire development set). Unassigned cases were grouped as ‘not a specific procedure’. Twenty-four ‘primary’ cardiac diagnoses and separately a categorisation of ‘univentricular’ status were defined using a hierarchical algorithm developed by the study team based on International Paediatric and Congenital Cardiac codes. Comorbidities considered included prematurity (< 37 weeks' gestation), Down syndrome, constellations of features that constitute a recognised syndrome, congenital structural defects of organs other than the heart and acquired conditions. Other candidate variables included use of bypass and patient age, weight and sex. Data were analysed using logistic regression.

Results

In the development set, there were 25,665 episodes that resulted in survival to 30 days, 693 episodes for which the vital status at 30 days was unknown and 854 episodes that resulted in death within 30 days in the development set (mortality 3.2% overall). The risk model developed includes the following factors: specific procedure, primary cardiac diagnosis grouped into low-, medium- and high-risk categories, univentricular heart status, age band (neonate, infant, child), continuous age, continuous weight, presence of a comorbidity other than Down syndrome and use of bypass. To account for decreasing mortality over time in the development set, a binary indicator for operations performed after 1 January 2007 is also included in the model. We were able to calculate a risk score for 95% of cases in the test set: weight was missing in 5% of cases. Data completeness improved over time. The proposed model discriminated well: the area under the receiver operating characteristic curve (AUC) for the test set was 0.77 (0.81 for post-2007 data). Removal of all but procedural information gave a reduced AUC of 0.72. The model performed well across the spectrum of predicted risk in the entire data set, but there was underestimation of mortality risk in the test set among neonates operated from 2007.

Limitations

An important limitation is that the model pertains to short-term 30-day outcomes (not long-term outcomes) and is designed for the purpose of routine monitoring for quality assurance rather than bedside-type predictions for individual patients. Over the recent period in the validation set (since 2007), the model was found to underestimate risk at the very high-risk end (> 10% risk), in particular among neonates. This indicates that risk adjustment based on the current parameterisation of the model will potentially give an unduly negative impression of outcomes at those centres with a high proportion of high-risk cases. Finally, any risk model used for ongoing quality improvement initiatives needs to be regularly updated as data quality improves and clinical practice evolves.

Conclusions

For the first time diagnostic information has been successfully incorporated into risk adjustment for short-term outcomes in this patient group, which added discriminatory power. The risk model is fit for purpose, although the underestimation of risk in recent neonates is an important caveat. Several centres have expressed an interest in piloting the risk model and the accompanying monitoring tool. Future work includes developing software to generate variable life-adjusted display charts within units using the risk model; using the risk model to explore trends in case mix over time; and informing future work in evaluating long-term outcomes for children with CHD.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Increased health burden associated with Clostridium difficile diarrhoea in patients with inflammatory bowel disease

BACKGROUND

Clostridium difficile (C. difficile) infection in hospitals in developed countries continues to be a major public health hazard despite increased control measures including review of antibiotic policies and hygiene measures. Patients with colitis are thought to be particularly vulnerable to C. difficile associated diarrhoea (CDAD). Identifying the clinical burden among hospitalised patients admitted with inflammatory bowel disease is an essential first step towards identifying and treating severe C. difficile infection in such individuals.

AIM

To determine excess morbidity and in-hospital mortality associated with hospital acquired CDAD in patients with inflammatory bowel disease (IBD-CDAD-HAI) admitted to NHS hospitals in England compared with those admitted for inflammatory bowel disease alone.

METHODS

Time trends study of all admissions to NHS hospitals between 2002/03 and 2007/08. We developed case definitions for IBD-CDAD-HAI patients. The primary outcomes were in-hospital mortality and length of stay. The secondary outcome was gastrointestinal surgery.

RESULTS

Patients in the IBD-CDAD-HAI group were more likely to die in hospital (adjusted OR 6.32), had 27.9 days longer in-patient stays and higher gastrointestinal surgery rates (adjusted OR 1.87) than patients admitted for inflammatory bowel disease alone.

CONCLUSION

Patients with inflammatory bowel disease admitted to NHS hospitals in England with co-existent C. difficile infection are at risk of greater in-hospital mortality and morbidity than patients admitted for inflammatory bowel disease alone.

Volume analysis of outcome following restorative proctocolectomy

BACKGROUND

This observational study aimed to determine national provision and outcome following pouch surgery (restorative proctocolectomy, RPC) and to examine the effect of institutional and surgeon caseload on outcome.

METHODS

All patients undergoing primary RPC between April 1996 and March 2008 in England were identified from the administrative database Hospital Episode Statistics. Institutions and surgeons were categorized according to the total RPC caseload performed over the study interval.

RESULTS

Some 5771 primary elective pouch procedures were undertaken at 154 National Health Service hospital trusts. Median follow-up was 65 (interquartile range (i.q.r.) 28-106) months. The 30-day in-hospital mortality rate was 0·5 per cent and the 1-year overall mortality rate 1·5 per cent. Some 30·5 per cent of trusts performed fewer than two procedures per year, and 91·4 per cent of surgical teams (456 of 499) carried out 20 or fewer RPCs over 8 years. Median surgeon volume was 4 (i.q.r. 1-9) cases. Failure occurred in 6·4 per cent of cases. Low-volume surgeons operated on more patients at the extremes of age (P < 0·001) and a lower proportion with ulcerative colitis (P < 0·001). Older age, increasing co-morbidity, increasing social deprivation, and both lower provider and surgeon caseload were independent predictors of longer length of stay. Older patient age and low institutional volume status were independent predictors of failure.

CONCLUSION

Many English institutions and surgeons carry out extremely low volumes of RPC surgery. Case selection differed significantly between high- and low-volume surgeons. Institutional volume and older age were positively associated with increased pouch failure.

Diverticular disease hospital admissions are increasing, with poor outcomes in the elderly and emergency admissions

BACKGROUND

Diverticular disease has a changing disease pattern with limited epidemiological data.

AIM

To describe diverticular disease admission rates and associated outcomes through national population study.

METHODS

Data were obtained from the English 'Hospital Episode Statistics' database between 1996 and 2006. Primary outcomes examined were 30-day overall and 1-year mortality, 28-day readmission rates and extended length of stay (LOS) beyond the 75th percentile (median inpatient LOS = 6 days). Multiple logistic regression analysis was used to determine independent predictors of these outcomes.

RESULTS

Between the study dates 560 281 admissions with a primary diagnosis of diverticular disease were recorded in England. The national admission rate increased from 0.56 to 1.20 per 1000 population/year. 232 047 (41.4%) were inpatient admissions and, of these, 55 519 (23.9%) were elective and 176 528 (76.1%) emergency. Surgery was undertaken in 37 767 (16.3%). The 30-day mortality was 5.1% (n = 6735) and 1-year mortality was 14.5% (n = 11 567). The 28-day readmission rate was 9.6% (n = 21 160). Increasing age, comorbidity and emergency admission were independent predictors of all primary outcomes.

CONCLUSIONS

Diverticular disease admissions increased over the course of the study. Patients of increasing age, admitted as emergency and significant comorbidity should be identified, allowing management modification to optimize outcomes.

UK Consensus Conference on Acute Medicine

The ageing population and the growth in numbers of patients suffering from long-term conditions demands an adequate response from the health service to provide care and support. This is particularly true when individuals experience an acute deterioration in their health: they have a right to expect prompt, effective treatment from competent clinicians who are properly equipped. This pressure on the NHS has been reflected in the increasing numbers of acute admissions to medical beds and the increasing percentage of acute bed days occupied by patients aged over 80 years. Recognizing the need to provide good care at the front door, the NHS looked for solutions and appointed a number of doctors to manage acute medical units. None of these doctors had been trained specifically for this task but, subsequently, training programmes were developed. However, the place of acute medicine remains the subject of debate.

Diverticular disease increases and effects younger ages: an epidemiological study of 10-year trends

INTRODUCTION

Little data exists on epidemiological trends of diverticular disease (DD). This study of 2,979 admissions over 10 years aimed to examine the epidemiological trends of DD admissions and clinical outcomes.

METHODS

A retrospective analysis of all admissions with DD from 1995 to 2004 was performed. General population data for the area was obtained from the national Census and local primary care trust.

RESULTS

Annual admissions for DD increased from 71 to 263 (p = 0.000). There was a trend of decreasing mean age from 71.2 years in 1995 to 68.1 in 2004 (p = 0.06). Admissions younger than 50 years increased from eight in 1995 to 42 in 2003 (p = 0.005). The mean age and size of the catchment population remained stable in that time. More emergency admissions underwent surgery (14.4%, n = 54) than electives (6.1%, n = 66) and had longer lengths of stay (25.2 vs. 9.2 days; p = 0.000). More patients under 50 (19.6%, n = 21) had surgery compared with older ones (8.8%, n = 100; p = 0.000). Recurrent admissions increased from 18 to 72 per year (p = 0.000) but were not associated with poor clinical outcomes. There were 21 deaths overall. Deaths were more likely in emergencies (p = 0.000, OR = 56.42) and those aged over 80 (p = 0.000, OR = 2.87). Mortality was independent of co-morbidity and other demographic factors.

CONCLUSION

DD admissions increased, unexplained by an ageing population, increasingly affecting younger patients who are more likely to undergo surgery, particularly as emergencies. Emergency admissions are associated with longer stay and higher mortality. Recurrent admission cannot be used as guide to elective surgery. Efforts should be made to treat more DD electively.

A national perspective on the decline of abdominoperineal resection for rectal cancer

OBJECTIVE

To assess rates of abdominoperineal excision of the rectum (APER) for rectal cancer between centers and over time, and to evaluate the influence of patient characteristics, including social deprivation, on APER rate.

METHODS

Data on patients undergoing APER or anterior resection (AR) in England were extracted from a national administrative database for the years 1996 to 2004. The primary outcome was the proportion of patients presenting with rectal cancer undergoing APER. Hierarchical logistic regression was used to identify independent factors associated with a nonrestorative resection.

RESULTS

Data on 52,643 patients were analyzed, 13,109(24.9%) of whom underwent APER. The APER rate significantly reduced over the study period from 29.4% to 21.2% (P < 0.001). Operative mortality following AR decreased significantly during the period of study (5.1% to 4.2%, P = 0.002), while that following APER did not (P = 0.075). Male patients were more likely to undergo APER (P < 0.001), whereas those with an emergency presentation more commonly underwent AR (P < 0.001). Independent predictors of increased APER rate were male gender (odds ratio [OR] = 1.239, P < 0.001) and social deprivation (most vs. least deprived; OR = 1.589, P < 0.001), whereas increasing patient age (OR = 0.977, P = 0.027 per 10-year increase), year of study (2003/4 vs. 1996/7; OR = 0.646, P < 0.001) and initial presentation as an emergency (OR = 0.713, P < 0.001) were associated with lower APER rates. After accounting for case-mix, there was significant between-center variability in APER rates.

CONCLUSION

Socially deprived patients were more likely to undergo abdominoperineal resection. Significant improvements in rates of nonrestorative resection were seen over time but although short-term outcomes following AR have improved, those following APER have not. Permanent stoma rates following rectal cancer surgery may be considered a surrogate marker of surgical quality.

Comparison of administrative data with the Association of Coloproctology of Great Britain and Ireland (ACPGBI) colorectal cancer database

BACKGROUND

This study compared case volume and operative mortality from surgery for colorectal cancer in England derived from Hospital Episode Statistics (HES) with the Association of Coloproctology of Great Britain and Ireland (ACPGBI) colorectal cancer database.

MATERIALS AND METHODS

Data extracted from HES records for 2001-2002 for patients undergoing one of seven procedures for colorectal cancer were compared with those from the ACPGBI database. The primary endpoint was a 30-day post-operative mortality.

RESULTS

16,346 patients from HES were compared with 7,635 from the ACPGBI database. For trusts with patients in both databases, HES reported 12% more procedures than ACPGBI (7,516 vs 6,617). Records of anterior resection revealed reasonable agreement between HES and the ACPGBI databases (difference, 2%). By trust, the overall correlation between the reported procedures was 0.660. Reported crude mortality was inconsistent between the databases, with mortality from abdominoperineal excision of rectum showing the poorest correlation (r = 0.253).

CONCLUSIONS

Overall, agreement between reported caseload and mortality was reasonable at a national, but not hospital, level. Investigation of differences between the two databases at unit level may help to detect under reporting of cases. The combination of data from both sources could be used to develop an enhanced system for monitoring outcomes from colorectal surgery in England.

Oesophagectomy practice and outcomes in England

Background

The 2001 UK National Health Service guidance on improving outcomes recommended centralization of oesophageal resection. The aim of this study was to analyse national trends in oesophageal resection in England to determine whether centralization has occurred and its impact on outcomes.

Methods

The study used data from Hospital Episode Statistics for 1997–1998 to 2003–2004 and included patients who had resection for oesophageal cancer. The annual hospital volume was grouped into five categories based on the recommendation for annual volume for a designated centre.

Results

A total of 11 838 oesophageal resections were performed. The total number of hospitals performing resections decreased, mainly owing to a fall in the number of very low-volume hospitals (117 in 1997 to 45 in 2003). The proportion of resections performed in very high-volume hospitals increased from 17·8 per cent during 1997–1999 to 21·9 per cent during 2002–2003 (P &lt; 0·001). The overall in-hospital mortality rate was 10·1 per cent, with a significant reduction over time (from 11·7 to 7·6 per cent; P &lt; 0·001). The decline in mortality rate may be due to increased numbers of patients undergoing surgery in higher-volume hospitals. There was an increase in the annual number of new patients from 5672 to 6230 during the study, although a fall in the proportion of resections from 31·5 to 26·0 per cent (P &lt; 0·001).

Conclusion

Centralization and multidisciplinary team expertise partly explain the improvement in mortality rate, but changes in preoperative selection also play a part.

Funnel plots, performance variation and the Myocardial Infarction National Audit Project 2003-2004

Background

Clinical governance requires health care professionals to improve standards of care and has resulted in comparison of clinical performance data. The Myocardial Infarction National Audit Project (a UK cardiology dataset) tabulates its performance. However funnel plots are the display method of choice for institutional comparison. We aimed to demonstrate that funnel plots may be derived from MINAP data and allow more meaningful interpretation of data.

Methods

We examined the attainment of National Service Framework standards for all hospitals (n = 230) and all patients (n = 99,133) in the MINAP database between 1^st April 2003 and 31^st March 2004. We generated funnel plots (with control limits at 3 sigma) of Door to Needle and Call to Needle thrombolysis times, and the use of aspirin, beta-blockers and statins post myocardial infarction.

Results

Only 87,427 patients fulfilled criteria for analysis of the use of secondary prevention drugs and 15,111 patients for analysis by Door to Needle and Call to Needle times (163 hospitals achieved the standards for Door to Needle times and 215 were within or above their control limits). One hundred and sixteen hospitals fell outside the 'within 25%' and 'more than 25%' standards for Call to Needle times, but 28 were below the lower control limits. Sixteen hospitals failed to reach the standards for aspirin usage post AMI and 24 remained below the lower control limits. Thirty hospitals were below the lower CL for beta-blocker usage and 49 outside the standard. Statin use was comparable.

Conclusion

Funnel plots may be applied to a complex dataset and allow visual comparison of data derived from multiple health-care units. Variation is readily identified permitting units to appraise their practices so that effective quality improvement may take place.

Measurement of the safety and quality of health care

Measurement of safety and quality is fundamental to health care delivery. A variety of measures are needed to fully understand the system; quantitative and qualitative measures are both useful in different ways. Measures need to be valid, reliable, accurate, timely, collectable, meaningful, relevant and important to those who will use them. Clinicians value appropriate measures and respond to them.

Operative mortality after colorectal resection in the Netherlands

Background

The aim of this study was to quantify factors related to operative mortality after colorectal resection in the Netherlands.

Methods

Multilevel logistic regression modelling was used. Institutional effects were calculated with and without adjustment for specific patient (age, sex, urgency of operation) and hospital (number of procedures, type of hospital) characteristics. All adult Dutch patients who underwent primary colorectal resection between 1994 and 1999 were included, except those who had (sub)total colectomy or local rectal resection.

Results

A total of 67 594 patients underwent colorectal resection. The in-hospital mortality rate was 7·0 per cent (elective 3·9 per cent, acute 14·3 per cent). Acute operation (odds ratio 3·89) and age (odds ratios 2·63, 5·23 and 10·13 for patients aged 50–69, 70–79 and 80 or more years respectively compared with those aged less than 50 years) had the strongest effects, followed by male sex (odds ratio 1·48) and type of hospital. There was no difference in operative mortality rate between low-, medium- and high-volume hospitals.

Conclusion

In the Netherlands, advanced age and acute operation are by far the most important factors related to operative mortality after colorectal resection. Male sex and type of hospital have only a modest effect, and there is no discernible effect of hospital volume.

Defining the minimum hospital case-load to achieve optimum outcomes in radical cystectomy

OBJECTIVE

To define 'high-' and 'low-' volume hospitals for radical cystectomy, and the minimum caseload required for a hospital to achieve optimum outcomes, as a relationship between increasing surgical case volume and improved outcomes in radical urological surgery has been suggested in recent North American studies.

METHODS

All cystectomies for urological cancer in England over 5 years were analysed from Hospital Episode Statistics (HES) data. The data were analysed statistically to describe the relationship between each hospital's annual case volume and two outcome measures: in-hospital mortality rate (MR) and hospital stay.

RESULTS

In all, there were 6317 cystectomies in 210 centres, with an overall MR of 5.6%. There was a significant inverse correlation (-0.733, P < 0.01) between hospital case volume and MR. Applying 95% confidence intervals, the minimum caseload required to achieve optimum outcomes was 11 procedures/year. Increasing the caseload beyond this minimum did not produce a significant reduction in MR.

CONCLUSION

Analysis of HES data confirms an inverse relationship between hospital caseload and mortality for radical cystectomy. A caseload of 11 operations/year is associated with the lowest MR.

The burden of paediatric intensive care: an Australian and New Zealand perspective

Most seriously ill children in Australia and New Zealand are cared for in specialised intensive care units associated with tertiary children's hospitals. Highly regionalised models of care are in operation. Children from remote areas are transported to intensive care by paediatric emergency transport services. Indigenous children have disease and injury patterns similar to parts of the developing world and are over-represented in the intensive care population. The outcome for children admitted to intensive care compares favourably with international benchmarks. There is also evidence of uniformity of outcomes across paediatric intensive care units in the region and that outcomes have been improving. Although there are some downward pressures on intensive care workloads (preventative strategies such as immunisation, safety campaigns), these are counterbalanced by new surgical initiatives and increasing expectations of extended high tech support for children with life shortening diseases and disabilities. This expanding group of technology-dependent children will be one of the major challenges facing health authorities and intensive care physicians in this region in the coming decade.

Regional differences in outcome from subarachnoid haemorrhage

BACKGROUND

Surgeons are increasingly placed under pressure to accept publication of their results and to abide by recommendations to change practice which others derive. Considerable concern exists about misinterpretation of such data. The issue is well illustrated by this study.

METHOD

Data on outcome following treatment for subarachnoid haemorrhage were prospectively collected from 1993-1998 in two centres in the British Isles: Newcastle and Nottingham.

FINDINGS

Initial examination of this data suggest a substantial difference in the performance favouring Nottingham over Newcastle. The odds of a poor outcome was 1:1.86 in Newcastle compared with 1:4.26 in Nottingham giving an odds ratio of 2.3 in favour of Nottingham and this difference was highly significant with p<0.00001. On a more detailed examination taking account of confounding variables, this difference disappeared entirely. Newcastle was able to operate a less selective admissions policy than Nottingham because of the deficiency of beds at the latter unit. A summary of these results has been published elsewhere.

INTERPRETATION

These results illustrate the dangers of applying statistical tools developed for simpler situations such as industrial process control to complex medical problems. We conclude that comprehensive and accurate data on all factors likely to influence the outcome for a particular treatment should be collected as an absolute prerequisite to any judgments being made on apparent statistical differences between the performances of differing units.

Quantification of mortality risk after abdominal aortic aneurysm repair

Background

The study was designed to evaluate the Acute Physiology And Chronic Health Evaluation (APACHE) II risk scoring system in abdominal aortic aneurysm (AAA) surgery. The aim was to create an APACHE-based risk stratification model for postoperative death.

Methods

Prospective postoperative APACHE II data were collected from patients undergoing AAA repair over a 9-year interval from 24 intensive care units (ICUs) in the Thames region. A multilevel logistic regression model (APACHE-AAA) for in-hospital mortality was developed to adjust for both case mix and the variation in outcome between ICUs.

Results

A total of 1896 patients were studied. The in-hospital mortality rate among the 1289 patients who had elective AAA repair was 9·6 (95 per cent confidence interval (c.i.) 8·0 to 11·2) per cent and that among the 605 patients who had an emergency repair was 46·9 (95 per cent c.i. 43·0 to 50·9) per cent. Four independent predictors of death were identified: age (odds ratio (OR) 1·05 (95 per cent c.i. 1·03 to 1·07) per year increase), Acute Physiology Score (OR 1·14 (95 per cent c.i. 1·12 to 1·17) per unit increase), emergency operation (OR 4·86 (95 per cent c.i. 3·64 to 6·52)) and chronic health dysfunction (OR 1·43 (95 per cent c.i. 1·04 to 1·97)). The APACHE-AAA model was internally valid, as shown by calibration (Hosmer–Lemeshow C statistic: χ2 = 6·14, 8 d.f., P = 0·632), discrimination properties (area under receiver–operator characteristic curve 0·845) and subgroup analysis. There was no significant variation in outcome between hospitals.

Conclusion

APACHE-AAA was shown to be an accurate risk-stratification model that could be used to quantify the risk of death after AAA surgery. It might also be used to determine the relative impact of ICU over high-dependency unit care.

Was Rodney Ledward a statistical outlier? Retrospective analysis using routine hospital data to identify gynaecologists' performance

OBJECTIVES

To investigate whether routinely collected data from hospital episode statistics could be used to identify the gynaecologist Rodney Ledward, who was suspended in 1966 and was the subject of the Ritchie inquiry into quality and practice within the NHS.

DESIGN

A mixed scanning approach was used to identify seven variables from hospital episode statistics that were likely to be associated with potentially poor performance. A blinded multivariate analysis was undertaken to determine the distance (known as the Mahalanobis distance) in the seven indicator multidimensional space that each consultant was from the average consultant in each year. The change in Mahalanobis distance over time was also investigated by using a mixed effects model.

SETTING

NHS hospital trusts in two English regions, in the five years from 1991-2 to 1995-6. Population Gynaecology consultants (n = 143) and their hospital episode statistics data.

MAIN OUTCOME MEASURE

Whether Ledward was a statistical outlier at the 95% level.

RESULTS

The proportion of consultants who were outliers in any one year (at the 95% significance level) ranged from 9% to 20%. Ledward appeared as an outlier in three of the five years. Our mixed effects (multi-year) model identified nine high outlier consultants, including Ledward.

CONCLUSION

It was possible to identify Ledward as an outlier by using hospital episode statistics data. Although our method found other outlier consultants, we strongly caution that these outliers should not be overinterpreted as indicative of "poor" performance. Instead, a scientific search for a credible explanation should be undertaken, but this was outside the remit of our study. The set of indicators used means that cancer specialists, for example, are likely to have high values for several indicators, and the approach needs to be refined to deal with case mix variation. Even after allowing for that, the interpretation of outlier status is still as yet unclear. Further prospective evaluation of our method is warranted, but our overall approach may be potentially useful in other settings, especially where performance entails several indicator variables.

Conversion rates in laparoscopic colorectal surgery: a predictive model with, 1253 patients

BACKGROUND

This study aimed all develop a mathematical model for predicting the conversion rate for patients undergoing laparoscopic colorectal surgery.

METHOD

This descriptive single-center study used routinely collected clinical data from 1,253 patients undergoing laparoscopic surgery between November 1991 and April 2003. A two-level hierarchical regression model was used to identify patient, surgeon, and procedure-related factors associated with conversion of laparoscopic to open surgery. The model was internally validated and tested using measures of discrimination and calibration. Exclusion criteria for laparoscopic colectomy included a body mass greater than 50, lesion diameter exceeding 15 cm, and multiple prior major laparotomies (exclusive of appendectomy, hysterectomy, and cholecystectomy).

RESULTS

The average conversion rate for the study population was 10.0% (95% confidence interval [CI], 8.3-11.7%). The independent predictors of conversion of laparoscopic to open surgery were the body mass index (odds ratio [OR], 2.1 per 10 Americans Society of Anesthesiology units increase), (ASA) grade 3 or 4, 1 or 2 (OR, 3.2, 5.8), type of resection (low rectal, left colorectal, right colonic vs small/other bowel procedures; OR, 8.82, 4.76, 2.98), presence of intraoperative abscess (OR, 3.60) or fistula (OR, 4.73), and surgeon seniority (junior vs senior staff OR, 1.56). The model offered adequate discrimination (area under receiver operator characteristic curve, 0.74) and excellent agreement (p = 0.384) between observed and model-predicted conversion rates (range of calibration, 3-32% conversion rate).

CONCLUSIONS

Laparoscopic conversion rates are dependent on a multitude of factors that require appropriate adjustment for case mix before comparisons are made between or within centers. The Cleveland Clinic Foundation (CCF) laparoscopic conversion rate model is a simple additive score that can be used in everyday practice to evaluate outcomes for laparoscopic colorectal surgery.