Ravi Maheswaran

Background: There are disparities in the prevalence of peripheral arterial disease (PAD). This study examined socioeconomic, ethnic, and geographical variations in population-based revascularization rates for PAD and the associations between these rates and PAD-related major lower limb amputation. Methods: Hospital admissions in England (April 2008–March 2018) for revascularization for moderate and severe PAD, and for major lower limb amputation, were examined using a population-based study design and Poisson and logistic regression. Results: In the 10-year time span, there were 309 839 revascularization admissions (44% severe PAD, 56% moderate PAD; > 90% White ethnicity) and 38 601 major lower limb amputations from a population aged ≥ 25 years of 36 million. Overall, 39.9% of patients with amputation had previously had revascularization. Revascularization rates for moderate and severe PAD and amputation rates increased with increasing socioeconomic deprivation. The ratio of amputations to revascularizations also increased with increasing deprivation, and patients admitted for revascularization from more deprived areas had more severe PAD. Revascularization rates for patients of Black ethnicity were generally substantially lower than those for patients of White ethnicity, the only exception being for severe PAD in patients aged ≥ 65 years. The amputation rate was also lower but the ratio of amputations to revascularizations, and the percentage of revascularization admissions with severe PAD, were higher for patients of Black relative to White ethnicity. Revascularization and amputation rates were substantially lower, and the ratio of amputations to revascularizations was also lower, for patients of Asian relative to White ethnicity, but patients of Asian ethnicity admitted for revascularization had a marginally higher percentage of severe PAD. There was substantial variation in revascularization and amputation rates across Integrated Care Board areas, with high rates in the North and in parts of the Midlands and South West. There was also wide variation in the ratio of amputations to revascularizations. Conclusion: There were substantial socioeconomic, geographical and ethnic disparities in revascularization rates in England.

Background: Amputation is a treatment of last resort for peripheral arterial disease. This study examined associations between socioeconomic deprivation, ethnicity, above-knee amputation (AKA) and below-knee amputation (BKA) rates, and post-amputation survival in England. Methods: Hospital Episode Statistics data identified patients aged ≥25 years who underwent an AKA or BKA related to peripheral arterial disease in 2006-2018. Data on ethnicity, comorbidity and socioeconomic deprivation was recorded. An ecological study design, based on population-level data, analysed amputation rates (Poisson regression), and a cohort study design investigated mortality subsequent to amputation (Cox regression). Results: Within a population of 35.7 million people aged ≥25 years, 47 249 patients underwent peripheral arterial disease-related major amputation over 12 years (94.1% White, 1.9% Black, and 1.6% Asian ethnicity). AKA : BKA ratios were 1.03, 0.73, and 0.80 for White, Black, and Asian ethnicities respectively. Amputation rates increased with increasing socioeconomic deprivation. The amputation rate ratio for the most relative to the least deprived category varied with age, ranging from 4.94 (95% confidence interval 4.24 to 5.75) for age 45–54 years to 1.35 (1.21 to 1.49) for age ≥85 years for AKA, and from 3.88 (3.44 to 4.37) to 1.12 (0.97 to 1.29) for BKA. Post-amputation mortality hazard ratios also increased with increasing socioeconomic deprivation, ranging from 1.26 (1.04 to 1.53) for age 25–54 years to 1.11 (1.03 to 1.19) for age ≥75 years for AKA, and from 1.25 (1.08 to 1.46) to 1.17 (1.08 to 1.27) for BKA. Over 12 years, amputation rates decreased in all socioeconomic categories in the population aged ≥65 years, but there was little change in the population aged 25–64 years. Black ethnicity was associated with lower adjusted AKA and BKA rate ratios relative to White ethnicity in those aged 25–64 years, and similar AKA but higher BKA rate ratios in those aged ≥65 years. Black ethnicity was also associated with lower post-amputation mortality, except in those aged 25–54 years within 90 days of BKA. Asian ethnicity was associated with lower AKA and BKA rate ratios relative to White ethnicity, but similar post-amputation mortality with some exceptions. Conclusion: The main policy and practice implications relate to socioeconomic inequalities. Greater efforts are needed in disadvantaged areas to prevent and manage peripheral arterial disease and reduce amputation.

Background: A national guideline on peripheral arterial disease management in England was issued in August 2012. The impact on revascularization rates was examined and variation with socioeconomic deprivation assessed. Methods: Annual hospital admissions for England over 10 years (2008–2009 to 2017–2018) were examined using interrupted time series analysis. A pragmatic approach was used to classify admissions for revascularization into moderate and severe categories. Results: There were 309 839 admissions (56% for moderate peripheral arterial disease), with an overall annual admission rate for revascularization of 86 per 100 000 population aged 25+ years. The rate for moderate peripheral arterial disease marginally increased by 0.29 per 100 000 per year (95% c.i. −0.22 to 0.80) from 2008–2009 to 2012–2013. Following guideline introduction, this rate decreased. The equivalent for severe peripheral arterial disease increased by 1.33 per 100 000 (0.78 to 1.88). Following guideline introduction, this rate plateaued. The change in rate (slope) for moderate peripheral arterial disease of −2.81 per 100 000 per year (−3.52 to −2.10) after guideline introduction was greater than the change in rate for severe peripheral arterial disease of −1.95 per 100 000 per year (−2.73 to −1.17). For moderate peripheral arterial disease, the annual rate in the most socioeconomically deprived category was 15.6 per 100 000 lower in 2017–2018 compared with 2012–2013 (24.3% decrease). The impact progressively diminished with decreasing deprivation. In the least deprived category, the reduction was 5.2 per 100 000 (12.9% decrease). For severe peripheral arterial disease, the decrease was 1.2 per 100 000 (3.1% reduction) with no consistent variation in relation to deprivation. Conclusion: Introduction of the national peripheral arterial disease management guideline in England was associated with a reduction in admission rates for revascularization, especially for moderate peripheral arterial disease, with greater reduction in rates for moderate peripheral arterial disease in more socioeconomically deprived areas. Association, however, does not necessarily imply causation and alternative explanations cannot be ruled out.

Above and below knee amputation (AKA, BKA) are treatments of last resort for peripheral arterial disease (PAD). The aim was to examine amputation rates, AKA:BKA ratios, previous revascularization and minor amputation, lengths of stay in hospital, mortality following amputation, and regional variation in people with and without diabetes in England. The study used population-based ecological and cohort study designs, 31 672 census areas, hospital admissions from 2006 to 2018 and Poisson, logistic and Cox regression. There were 47 249 major lower limb amputations (50.7% AKA; 48% had diabetes), giving an annual PAD-related amputation rate of 11 per 100 000 in the population aged 25+ years. Amputation rates were higher in men and substantially higher in people with diabetes. The AKA:BKA ratio was 0.63 in patients with diabetes (n = 22 702) and 1.62 in patients without diabetes (n = 24 547). Of patients having AKA, 25.3% died within 90 days of amputation compared with 11.9% for BKA. Median survival following amputation ranged from only 1.68 years following AKA in patients with diabetes to 5.72 years following BKA in patients without diabetes. Amputation rates decreased over time mainly in the population with diabetes. Short-term mortality and lengths of stay in hospital also decreased over time, while the percentage with previous revascularization generally increased. Amputation rates and AKA:BKA ratios were highest in the North. Adjustment for age, sex and deprivation did not substantially alter geographical patterns. Adjusted 90-day mortality was generally higher in the North and the Midlands but also high in London. There were also regional variations in adjusted duration from admission to amputation, duration from amputation to discharge or death in hospital, previous revascularization and previous minor amputation. There were large variations in amputation rates and survival following amputation in relation to diabetes status and amputation level, and regional variations which remained after adjustment for deprivation.

Background: Carotid artery disease and stroke are more prevalent in socioeconomically deprived areas. The aim was to investigate socioeconomic disparities in carotid artery disease surgery rates and in outcomes following surgery. Methods: The study used population-based ecological and cohort study designs, 31 672 census areas in England, hospital admissions from April 2006 to March 2018, the Index of Multiple Deprivation 2010 as the area-level deprivation indicator, and Poisson, logistic, and Cox regression. Results: A total of 54 377 patients (67 per cent men) from a population aged 55 years and older of 14.7 million had carotid artery disease procedures (95 per cent carotid endarterectomy). Carotid endarterectomy rates were 116 per cent (95% c.i. 101 to 132) higher in men and 180 per cent (95% c.i. 155 to 207) higher in women aged 55–64 years in the most compared with the least socioeconomically deprived areas by quintile. However, this difference diminished and appeared to reverse with increasing age, with 24 per cent (95% c.i. 14 to 33) and 12 per cent (95% c.i. −3 to 24) lower carotid endarterectomy rates respectively in men and women aged 85 years and older in the most deprived areas. Patients in deprived areas having carotid endarterectomy were more likely to have been admitted as symptomatic emergency carotid artery disease admissions. Mortality, and a combined outcome of mortality or stroke-related re-admission, were both worse in patients living in more deprived areas and were only partially accounted for by the higher prevalence of co-morbidities. There was, however, no clear pattern of association between deprivation and elective waiting time for carotid endarterectomy. Conclusions: These results provide evidence of socioeconomic disparities in surgery for carotid artery disease. Clear policies are needed to address these disparities.

Abdominal aortic aneurysm (AAA) is more prevalent in socioeconomically disadvantaged areas. This study investigated socioeconomic disparities in AAA repair rates and survival. The study used ecological and cohort study designs, from 31 672 census areas in England (April 2006 to March 2018), the Index of Multiple Deprivation 2010 as the area-level deprivation indicator, and Poisson, logistic and Cox regression. Some 77 606 patients (83.4 per cent men) in four age categories (55–64, 65–74, 75–84, 85 or more years) were admitted with AAA from a population aged at least 55 years of 14.7 million. Elective open and endovascular repair rates were 41 (95 per cent c.i. 23 to 61) and 60 (36 to 89) per cent higher respectively among men aged 55–64 years in the most versus least deprived areas by quintile. This differences diminished and appeared to reverse with increasing age, with 26 (−1 to 45) and 25 (13 to 35) per cent lower rates respectively in men aged 85 years or more in the most deprived areas. Men admitted from more deprived areas were more likely to die in hospital without aneurysm repair. Among those who had aneurysm repair, this was more likely to be for a ruptured aneurysm than among men from less deprived areas. For intact aneurysm repair, they were relatively more likely to have this during an emergency admission. The mortality rate after repair was higher for men from more deprived areas, although the hazard diminished with age. Patterns were unclear for women. There were clear socioeconomic disparities in operation rates, mode of presentation, and outcome for AAA surgery. Policies are needed to address these disparities.

Background: Varicose vein (VV) treatments have changed significantly in recent years leading to potential disparities in service provision. The aim of this study was to examine the trends in VV treatment in England and to identify disparities in the provision of day-case and inpatient treatments related to deprivation, ethnicity, and other demographic, and geographical factors. Method: A population-based study using linked hospital episode statistics for England categorized VV procedures and compared population rates and procedure characteristics by ethnicity, deprivation quintile, and geographical area. Results: A total of 311 936 people had 389 592 VV procedures between 2006/07 and 2017/18, with a further 63 276 procedures between 2018/19 and 2020/21. Procedure rates have reduced in all but the oldest age groups, whereas endovenous procedures have risen to more than 60 per cent of the total in recent years. In younger age groups there was a 20–30 per cent reduction in procedure rates for the least-deprived compared with the most-deprived quintiles. Non-white ethnicity was associated with lower procedure rates. Large regional and local differences were identified in standardized rates of VV procedures. In the most recent 5-year interval, the North-East region had a three-fold higher rate than the South-East region with evidence of greater variation between commissioners in overall rates, the proportion of endovenous procedures, and policies regarding bilateral treatments. Conclusions: There are substantial geographical variations in the provision of treatment for VVs, which are not explained by demographic differences. These have persisted, despite the publication of guidelines from the National Institute for Health and Care Excellence, and many commissioners, and providers would seem to implement policies that are contrary to this guidance. Lower rates of procedures in less-deprived areas may reflect treatments carried out in private practice, which are not included in these data.

Background: Vascular services is changing rapidly, having emerged as a new specialty with its own training and specialised techniques. This has resulted in the need for reconfiguration of services to provide adequate specialist provision and accessible and equitable services.Objectives: To identify the effects of service configuration on practice, resource use and outcomes. To model potential changes in configuration. To identify and/or develop electronic data collection tools for collecting patient-reported outcome measures and other clinical information. To evaluate patient preferences for aspects of services other than health-related quality of life.Design: This was a multiple methods study comprising multiple systematic literature reviews; the development of a new outcome measure for users of vascular services (the electronic Personal Assessment Questionnaire – Vascular) based on the reviews, qualitative studies and psychometric evaluation; a trade-off exercise to measure process utilities; Hospital Episode Statistics analysis; and the development of individual disease models and a metamodel of service configuration.Setting: Specialist vascular inpatient services in England.Data sources: Modelling and Hospital Episode Statistics analysis for all vascular inpatients in England from 2006 to 2018. Qualitative studies and electronic Personal Assessment Questionnaire – Vascular evaluation with vascular patients from the Sheffield area. The trade-off studies were based on a societal sample from across England.Interventions: The data analysis, preference studies and modelling explored the effect of different potential arrangements for service provision on the resource use, workload and outcomes for all interventions in the three main areas of inpatient vascular treatment: peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. The electronic Personal Assessment Questionnaire – Vascular was evaluated as a potential tool for clinical data collection and outcome monitoring.Main outcome measures: Systematic reviews assessed quality and psychometric properties of published outcome measures for vascular disease and the relationship between volume and outcome in vascular services. The electronic Personal Assessment Questionnaire – Vascular development considered face and construct validity, test–retest reliability and responsiveness. Models were validated using case studies from previous reconfigurations and comparisons with Hospital Episode Statistics data. Preference studies resulted in estimates of process utilities for aneurysm treatment and for travelling distances to access services.Results: Systematic reviews provided evidence of an association between increasing volume of activity and improved outcomes for peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. Reviews of existing patient-reported outcome measures did not identify suitable condition-specific tools for incorporation in the electronic Personal Assessment Questionnaire – Vascular. Reviews of qualitative evidence, primary qualitative studies and a Delphi exercise identified the issues to be incorporated into the electronic Personal Assessment Questionnaire – Vascular, resulting in a questionnaire with one generic and three disease-specific domains. After initial item reduction, the final version has 55 items in eight scales and has acceptable psychometric properties. The preference studies showed strong preference for endovascular abdominal aortic aneurysm treatment (willingness to trade up to 0.135 quality-adjusted life-years) and for local services (up to 0.631 quality-adjusted life-years). A simulation model with a web-based interface was developed, incorporating disease-specific models for abdominal aortic aneurysm, peripheral arterial disease and carotid artery disease. This predicts the effects of specified reconfigurations on workload, resource use, outcomes and cost-effectiveness. Initial exploration suggested that further reconfiguration of services in England to accomplish high-volume centres would result in improved outcomes, within the bounds of cost-effectiveness usually considered acceptable in the NHS.Limitations: The major source of evidence to populate the models was Hospital Episode Statistics data, which have limitations owing to the complexity of the data, deficiencies in the coding systems and variations in coding practice. The studies were not able to address all of the potential barriers to change where vascular services are not compliant with current NHS recommendations.Conclusions: There is evidence of potential for improvement in the clinical effectiveness and cost-effectiveness of vascular services through further centralisation of sites where major vascular procedures are undertaken. Preferences for local services are strong, and this may be addressed through more integrated services, with a range of services being provided more locally. The use of a web-based tool for the collection of clinical data and patient-reported outcome measures is feasible and can provide outcome data for clinical use and service evaluation.Future work: Further evaluation of the economic models in real-world situations where local vascular service reconfiguration is under consideration and of the barriers to change where vascular services do not meet NHS recommendations for service configuration is needed. Further work on the electronic Personal Assessment Questionnaire – Vascular is required to assess its acceptability and usefulness in clinical practice and to develop appropriate report formats for clinical use and service evaluation. Further studies to assess the implications of including non-health-related preferences for care processes, and location of services, in calculations of cost-effectiveness are required.Study registration: This study is registered as PROSPERO CRD42016042570, CRD42016042573, CRD42016042574, CRD42016042576, CRD42016042575, CRD42014014850, CRD42015023877 and CRD42015024820.Funding: This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 9, No. 5. See the NIHR Journals Library website for further project information.