Provision of vascular surgical services in the Oxford Region

Using clinical practice variations as a method for commissioners and clinicians to identify and prioritise opportunities for disinvestment in health care: a cross-sectional study, systematic reviews and qualitative study

Background

NHS expenditure has stagnated since the economic crisis of 2007, resulting in financial pressures. One response is for policy-makers to regulate use of existing health-care technologies and disinvest from inefficiently used health technologies. A key challenge to disinvestment is to identify existing health technologies with uncertain cost-effectiveness.

Objectives

We aimed to explore if geographical variation in procedure rates is a marker of clinical uncertainty and might be used by local commissioners to identify procedures that are potential candidates for disinvestment. We also explore obstacles and solutions to local commissioners achieving disinvestment, and patient and clinician perspectives on regulating access to procedures.

Methods

We used Hospital Episode Statistics to measure geographical variation in procedure rates from 2007/8 to 2011/12. Expected procedure numbers for each primary care trust (PCT) were calculated adjusting for proxies of need. Random effects Poisson regression quantified the residual inter-PCT procedure rate variability. We benchmarked local procedure rates in two PCTs against national rates. We conducted rapid systematic reviews of two high-use procedures selected by the PCTs [carpal tunnel release (CTR) and laser capsulotomy], searching bibliographical databases to identify systematic reviews and randomised controlled trials (RCTs). We conducted non-participant overt observations of commissioning meetings and semistructured interviews with stakeholders about disinvestment in general and with clinicians and patients about one disinvestment case study. Transcripts were analysed thematically using constant comparison methods derived from grounded theory.

Results

There was large inter-PCT variability in procedure rates for many common NHS procedures. Variation in procedure rates was highest where the diffusion or discontinuance was rapidly evolving and where substitute procedures were available, suggesting that variation is a proxy for clinical uncertainty about appropriate use. In both PCTs we identified procedures where high local use might represent an opportunity for disinvestment. However, there were barriers to achieving disinvestment in both procedure case studies. RCTs comparing CTR with conservative care indicated that surgery was clinically effective and cost-effective on average but provided limited evidence on patient subgroups to inform commissioning criteria and achieve savings. We found no RCTs of laser capsulotomy. The apparently high rate of capsulotomy was probably due to the coding inaccuracy; some savings might be achieved by greater use of outpatient procedures. Commissioning meetings were dominated by new funding requests. Benchmarking did not appear to be routinely carried out because of capacity issues and concerns about data reliability. Perceived barriers to disinvestment included lack of collaboration, central support and tools for disinvestment. Clinicians felt threshold criteria had little impact on their practice and that prior approval systems would not be cost-effective. Most patients were unaware of rationing.

Conclusions

Policy-makers could use geographical variation as a starting point to identify procedures where health technology reassessment or RCTs might be needed to inform policy. Commissioners can use benchmarking to identify procedures with high local use, possibly indicating overtreatment. However, coding inconsistency and limited evidence are major barriers to achieving disinvestment through benchmarking. Increased central support for commissioners to tackle disinvestment is needed, including tools, accurate data and relevant evidence. Early engagement with patients and clinicians is essential for successful local disinvestment.

Funding

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

Systematic review and meta-analysis of the relationship between hospital volume and outcome for lower limb arterial surgery

Background

The aim was to investigate whether a relationship existed between case volume and outcome for lower limb vascular surgical procedures.

Methods

PubMed, Embase, the Cochrane Library and Google Scholar were searched for all articles on population-based studies on the volume–outcome relationship for lower limb vascular surgery at hospital level. Outcomes were mortality and subsequent amputation after lower limb vascular surgery. The data were subjected to meta-analysis by outcome.

Results

Some 452 093 patients from ten studies were included in the systematic review and five studies were included in meta-analyses. Seven of these articles found a significant positive hospital–volume outcome relationship. The pooled effect estimate for mortality was odds ratio (OR) 0·81 (95 per cent confidence interval 0·71 to 0·91) and that for amputation was OR 0·88 (0·79 to 0·98), with better results being found after surgery at higher-volume hospitals. Significant heterogeneity was seen in the data.

Conclusion

Higher-volume hospitals were associated with reduced amputation and mortality rates after lower limb vascular surgery. These data were not as conclusive as those for other vascular surgical procedures owing to significant heterogeneity.

Regional vascular surgical units: a practical means of providing specialist services

BACKGROUND

A comprehensive regional emergency and elective vascular surgical service was established in Limerick Regional General Hospital between 1994 and 1996 following the appointment of three surgeons with vascular training.

AIM

To compare vascular surgical activity before and after the establishment of a regional vascular service.

METHODS

This study used local and national computerised databases, clinic letters, theatre registers and radiology records to compare vascular surgical activity before (1992) and after (1997) this service was established.

RESULTS

Total outpatient activity increased almost six-fold and total number of inpatient vascular procedures (including radiological) increased from 146 to 432, but the venous proportion declined from 70% to 36%. The number of major arterial procedures increased from 37 to 165 in 1997 including 10 carotid endarterectomies, 24 aortic reconstructions and 54 lower limb reconstructions representing rates of 3/100,000, 8/100,000 and 17/100,000 population respectively.

CONCLUSION

As substantial changes in disease patterns are unlikely, these data indicate that patients previously diverted elsewhere for therapy are now cared for within the health board region and that further increases in workload may be expected. We suggest that these data mandate the reallocation of resources to fund appropriately staffed and audited regional vascular units.

Accuracy of centrally recorded OPCS codes for vascular surgery in the United Kingdom

AIM

Centrally recorded OPCS codes are based upon district returns. The aim of this study is to determine the accuracy of this system with regard to vascular surgery.

METHODS

Prospectively recorded audit data for vascular and endovascular procedures were compared with those obtained from the Department of Health and Welsh Office. Five U.K. hospitals were involved in the study. Data were obtained for the twelve months, 1 April 1994-30 March 1995 (these being the most up to date figures available).

RESULTS

The total number of arterial reconstructions based on audit data was 1082. Those recorded by the OPCS codes were 743. This represents a discrepancy of -31.3% (range for the five hospitals: -13.1% to -63.8%). When examining specific codes similar discrepancies were seen. For example, in one hospital 38 AAA repairs were carried out but only two were centrally recorded. However, examination of ICD9 codes (relating to hospital admissions) for that hospital showed that 38 patients with AAA were admitted. A similar wide variation was seen when examining iliac and superficial femoral artery endovascular procedures. Despite the discrepancies of audit and OPCS data, the codes for reconstructions did reflect relative workload of the different hospitals.

CONCLUSION

This study shows that there is a marked underestimate of vascular workload when comparing central recorded data with that obtained from local audit. Marked variation is seen in the accuracy of data submitted from different hospitals.

Current management of acute leg ischaemia: results of an audit by the Vascular Surgical Society of Great Britain and Ireland

BACKGROUND

Management of acute leg ischaemia has changed in recent years. This study aimed to elucidate current practice throughout the UK and Ireland.

METHODS

Surgeons and audit departments were asked to return a questionnaire about every episode of acute leg ischaemia seen in the hospital between 1 January and 31 March 1996.

RESULTS

A total of 539 episodes were reported in 474 patients (248 men) aged 19-96 (median 73) years. Common causes were thrombosis in situ (41 per cent), embolism (38 per cent) and graft or angioplasty occlusion (15 per cent). Vascular surgical advice was requested in 95 per cent of cases. Initial management was: immediate embolectomy in 21 per cent, anticoagulants in 13 per cent and no vascular intervention in 10 per cent. Arteriography was done in 56 per cent, followed by 186 endovascular and 165 surgical interventions. At 30 days, 70 per cent of limbs were definitely viable and 16 per cent had been amputated. The mortality rate was 22 per cent. Cases were reported by 86 of 182 hospitals contacted, but some referred no patients, and a supplementary audit of 54 cases (10 per cent size of the original sample) from non-contributing hospitals showed no important differences.

CONCLUSION

Patients with acute leg ischaemia are generally treated by vascular specialists, with modern methods and acceptable results. This is being achieved despite insufficient vascular surgeons and radiologists for formal emergency rotas in most hospitals.

Survey of changes in the provision of vascular surgical services in the Oxford Region over 5 years

AIM

This study aimed to examine changes in the provision of vascular services in the Oxford region over 5 years.

METHODS

A questionnaire was sent to all general surgeons in the region asking of their involvement in vascular surgery. Data were obtained from the Department of Health concerning vascular procedures and inpatient codes for each district in the Oxford Region from 1990-1991 to 1994-1995. Office of Population Censuses and Surveys (OPCS) data for abdominal aortic aneurysm repair and femoral artery reconstruction were validated against data collected prospectively for West Berkshire.

RESULTS

Eighteen of 45 surgeons who replied to the questionnaire carried out elective and emergency arterial work. All were members of the Vascular Surgical Society of Great Britain and Ireland (VSS). All but one took part in the general surgical rota. Eight surgeons carried out emergency arterial surgery only; only two of these were members of the VSS. Of 19 surgeons undertaking no arterial surgery, 15 operated on primary and 11 on recurrent varicose veins. The number of arterial reconstructions rose from 20.8 per 100000 population to 28 per 100000 throughout the study. The greatest increase occurred in districts where a new vascular consultant had been appointed. Similar results were obtained with endovascular procedures. The number of major amputations remained fairly constant at approximately 11 per 100000 population. The number of inpatient episodes for arterial disease also rose, from 35.7 to 47.6 per 100000. In validating OPCS codes against prospectively collected data, discrepancies for individual years were noted but the annual trend was reflected fairly accurately by the codes.

CONCLUSION

There has been an increase in vascular activity in the region, but variations still exist between different districts.

A prospective survey of patients presenting with abdominal aortic aneurysm

OBJECTIVES

To define the presentation and management of patients presenting with abdominal aortic aneurysm (AAA) DESIGN AND SETTING: A prospective survey was carried out of all patients presenting to hospitals within the Oxford region.

MATERIALS AND METHODS

Data were collected by one surgeon in each hospital. Full details were collected onto data sheets.

RESULTS

One hundred and ninety patients presented, 141 electively, 46 with ruptured AAA and three with acute AAAs. In 53 patients presenting electively the aneurysm was small and surveillance started. Fifty-six patients underwent an operation, three patients died. Of 46 patients with a ruptured aneurysm 24 (52%) died. In 11 no operation was carried out and all of these patients died within 24 h. Operative mortality was 13 of 35 patients (37%). More patients with a ruptured AAA were transferred to the teaching hospital compared with a district general hospital (p < 0.05). This was reflected in a lower operative mortality in the teaching hospital.

CONCLUSIONS

The presentation of AAA in this study was approximately 15 per 100,000 population. Approximately one-third of patients presenting electively had small AAAs which required surveillance. A further third underwent an operation, the remaining patients being unfit. Approximately one-quarter of patients with a ruptured aneurysm did not undergo an operation. The operative mortality was 37%.

Outcome of symptomatic leg ischaemia: four year morbidity and mortality in Vadstena, Sweden

OBJECTIVE

To quantify cardiovascular morbidity and mortality including the incidence of vascular surgery and amputations, among individuals with symptomatic leg ischaemia.

DESIGN

Prospective cohort study.

MATERIAL

Inhabitants 50-89 years of age (n = 2784) of Vadstena community, Ostergötland, Sweden, with 4 years of follow-up. 107 subjects with symptomatic leg ischaemia (SLI), selected by a postal questionnaire and ankle pressure measurements, and an age and sex matched control group of 214 individuals.

CHIEF OUTCOME MEASURES

Cardiovascular morbidity and mortality, all cause mortality, surgical procedures for leg ischaemia, major amputations, ankle brachial pressure index.

MAIN RESULTS

Age and sex adjusted all-cause mortality risk in the SLI-group was increased by 1.9. This was most prominent among men in their sixties and women in their seventies. Cardiovascular mortality was increased by 1.9 (95% confidence interval 1.1-3.3). Relative risks for acute myocardial infarction and cerebrovascular events were 2.4 (1.1-5.1) and 1.7 (0.9-3.2), respectively. The increase in age and sex adjusted incidence of primary reconstructive surgery during the first year after initial examination was 67-fold compared to the total population of Vadstena 50-89 years old, and 18 fold for the whole observation period, while the increase in risk for major amputation during the observation period was 12-fold. Median ankle brachial index improved significantly during follow-up among the individuals alive and not subjected to vascular surgery.

CONCLUSIONS

Among the SLI-subjects identified in a general population, the overall risk for cardiovascular morbidity and mortality over 4 years was significantly increased compared to normals.

Amputation rates as a measure of vascular surgical results

Reconstructive surgery for critical leg ischaemia (CLI) increased in both hospital- and population-based patient samples over 12 years. In the referral centre amputation numbers were unchanged over this period, although amputation carried out for patients with CLI decreased from 58 to 35 per cent. In the population sample amputation numbers decreased by 25 per cent and amputations of patients with CLI decreased from 79 to 43 per cent. Patient characteristics and amputation patterns were different in the two settings. Amputation rates as a measure of the efficacy of an arterial reconstruction policy should be used only on a population basis. The analysis is skewed by selection bias in referral centres.

A cost-utility analysis of laser-assisted angioplasty for peripheral arterial occlusions

Despite the perception of many people that lasers represent the cutting edge of high-technology medicine, this form of medical technology has been subject to relatively little rigorous evaluation. This dearth of research relates particularly to economic evaluation, where there have been few attempts to justify the high cost of laser equipment. This paper details an economic evaluation of the use of laser technology as a secondary adjunct to angioplasty to treat peripheral arterial occlusions. Using data from a range of sources, including a published randomized trial, a cost-utility model is developed to estimate the costs and benefits of the laser, relative to standard angioplasty. The best available data indicate a cost-effective role for the laser, but important areas of uncertainty exist, including the laser's secondary recanalization rate, which has been estimated on the basis of limited numbers of patients. This uncertainty suggests that further research is required before widespread diffusion of the laser for use in this clinical context.

Late reoperation in vascular surgery

OBJECTIVES

Assessment of late reoperation (after 30 days) following vascular surgery.

DESIGN

Analysis of a prospectively collected database of consecutive patients undergoing vascular surgery.

SETTING

A single teaching unit's experience between 1986-1993.

MATERIALS

Patients undergoing 2501 primary arterial reconstructions.

CHIEF OUTCOME MEASURES

Reoperation after 30 days.

MAIN RESULTS

One hundred and fifty eight patients (6%) underwent further operations, at more than 1 month after the primary procedure. Primary procedures at highest risk for reoperations were axillobifemoral bypasses and femorodistal bypasses with respective late reoperation rates of 20% and 16%. The majority of patients required late reoperation because of graft occlusion or stenosis. Overall, of the 158 late reoperations performed, 114 were related to the same arterial segment with the same presenting symptoms as the primary operation, and 44 for a different indication. A second or subsequent reoperation was required in 54 patients and the overall operative mortality was 11%.

CONCLUSION

Patients undergoing certain vascular procedures, should be informed of the high risk of a subsequent procedure when consent is obtained.

Organisation of vascular surgical services: evolution or revolution?

The trend towards subspecialisation in hospital services is likely to lead to the development of vascular surgery as a separate specialty. If vascular surgery is to emerge as a high quality service then vascular emergencies--a substantial component of the workload--should be dealt with by surgeons with adequate training, and all patients should have equal access to the service. A specialist vascular surgical unit would have to be large enough to make efficient use of other services that it needs, such as radiology, and so may require the amalgamation of smaller health district units. Because of the differing local degrees of subspecialisation, national or regional strategies for vascular surgery must be developed.