Electronic personal assessment questionnaire for vascular conditions (ePAQ-VAS): development and validity.

BACKGROUND: This paper describes the development and validation of an electronic personal assessment questionnaire for vascular conditions (ePAQ-VAS) that captures the symptomatology, quality of life and clinically relevant data of patients presenting to vascular services. METHODS: A two-stage survey was conducted in patients attending a tertiary vascular department. Patients completed the ePAQ-VAS remotely online, or on site using an electronic tablet. In the first stage of the survey, the responses were used to perform confirmatory factor analysis to assess the construct validity and remove redundant items. The internal reliability of disease-specific scales was investigated. In the second stage of the survey, the acceptability, known-group validity, test-retest reliability, and responsiveness of ePAQ-VAS was assessed. RESULTS: In total, 721 patients completed ePAQ-VAS. Their mean(s.d.) age was 63·5(15·7) years and 468 (64·9 per cent) were men. Some 553 patients (76·7 per cent) completed the questionnaire in clinic and the remainder completed the questionnaire online. The results of the confirmatory factor analysis confirmed the conceptual model for ePAQ-VAS structure and eliminated six items. Internal reliability was acceptable for all the scales (Cronbach's α greater than 0·7). The test-retest reliability measured by the intraclass correlation coefficient ranged from 0·65 to 0·99. The results showed that the instrument was responsive over time with the standardized response mean ranging from 0·69 to 1·60. CONCLUSION: ePAQ-VAS is a holistic data-collection process that is relevant to vascular service users and has potential to contribute to patient-focused care and the collection of aggregate data for service evaluation. A demonstration version of the final version of ePAQ can be viewed at http://demo-questionnaire.epaq.co.uk/home/project?id=VASC_1.7&page=1.

ANTECEDENTES: Este artículo describe el desarrollo y la validación de un cuestionario electrónico de evaluación personal para enfermedades vasculares (ePAQ-VAS) que incluye la sintomatología, la calidad de vida y los datos clínicamente relevantes para los pacientes que son atendidos en los servicios de patología vascular. MÉTODOS: Se llevó a cabo una encuesta en dos fases entre los pacientes atendidos en un servicio de patología vascular de tercer nivel. Los pacientes completaron el cuestionario ePAQ-VAS a distancia en línea o bien en el centro hospitalario mediante una tableta electrónica. En la primera fase de la encuesta, las respuestas se utilizaron para realizar un análisis factorial de confirmación para evaluar la validez del diseño y eliminar los elementos redundantes. Se investigó la fiabilidad interna de las escalas específicas de la enfermedad. En la segunda fase de la encuesta, se evaluó la aceptabilidad, la validez de grupo conocida, la fiabilidad test-retest y la capacidad de respuesta del ePAQ-VAS. RESULTADOS: En total, 721 pacientes completaron el ePAQ-VAS, la edad media fue de 63,5 años (DE 15,7); el 64,9% eran varones (468); el 76% de los pacientes (553) completaron el cuestionario en la clínica y los pacientes restantes lo hicieron electrónicamente a distancia. Los resultados del análisis factorial de confirmación confirmaron el modelo conceptual para la estructura ePAQ-VAS y eliminaron seis ítems. La fiabilidad interna fue aceptable para todas las escalas (alfa de Cronbach > 0,7). La fiabilidad test-retest medida por el coeficiente de correlación intraclase osciló entre 0,65-0,99. Los resultados mostraron que el instrumento responde con el tiempo con una media de respuesta estandarizada que varía de 0,69 a 1,60. CONCLUSIÓN: El ePAQ-VAS es un proceso holístico de recopilación de datos que es relevante para los usuarios de servicios de patología vascular y tiene el potencial de contribuir a la atención centrada en el paciente y a la recopilación de datos agregados para la evaluación del servicio.

Strength of public preferences for endovascular or open aortic aneurysm repair.

BACKGROUND: This study evaluated public preferences for the treatment processes for abdominal aortic aneurysm repair in order to allow them to be incorporated into a cost-effectiveness analysis. METHODS: This was a telephone survey using a trade-off method in UK resident adults (aged at least 18 years) with no previous diagnosis of a vascular condition. RESULTS: Some 167 of 209 participants (79·9 per cent) stated that they would prefer endovascular aneurysm repair (EVAR), 40 (19·1 per cent) preferred open surgery and two (1·0 per cent) stated no preference. Participants preferred EVAR because of the less invasive nature of the intervention and quicker recovery. Participants preferring open surgery cited reasons such as having a single follow-up appointment, and a procedure that felt more permanent. When participants were asked to make a sacrifice in order to have their preferred treatment, 122 (58·4 per cent) favoured EVAR, 18 (8·6 per cent) favoured open surgery and 69 (33·0 per cent) had no preference. Those preferring EVAR were willing to give up a mean of 0·135 expected quality-adjusted life-years (QALYs) to have EVAR, compared with a willingness to give up 0·033 expected QALYs among those preferring open repair. CONCLUSION: These results indicate a clear preference for EVAR over open surgery for aortic aneurysm.

ANTECEDENTES: Este estudio evaluó las preferencias de la opinion pública en relación a las opciones de tratamiento para la reparación del aneurisma de aorta abdominal, con el objetivo de que dichas preferencias se puedan incorporar en un análisis de coste-efectividad. MÉTODOS: Se realizó una encuesta telefónica utilizando el método trade-off (solución de intercambio) en adultos residentes en el Reino Unido (mayores de 18 años) sin diagnóstico previo de enfermedad vascular. RESULTADOS: Un total de 167 (79,9%) de 209 participantes declararon que preferirían la reparación endovascular del aneurisma (endovascular aneurysm repair, EVAR), 40 (19,1%) prefirieron cirugía abierta y dos (1,0%) no tenían preferencia. Los participantes prefirieron el EVAR debido a la naturaleza menos invasiva de la intervención y a tiempos de recuperación más rápidos. Los participantes que preferían la cirugía abierta mencionaron como razones tener una única visita de seguimiento y consideraron que se trataba de un procedimiento más permanente. Cuando se pidió a los participantes que para recibir su tratamiento preferido hicieran un intercambio, 122 (58,4%) se decantaron por la EVAR, 18 (8,6%) por la cirugía abierta y 69 (33%) no tuvieron preferencia. Los que prefirieron EVAR estaban dispuestos a renunciar a una media de 0,135 años de vida ajustados por calidad (QALYs) esperados con tal de recibir una EVAR en comparación con la renuncia de 0,033 QALYs esperada entre quienes preferían la reparación abierta. CONCLUSIÓN: Estos resultados indican una clara preferencia por la EVAR sobre la cirugía abierta, lo que está en desacuerdo con la reciente recomendación de NICE de que la EVAR no debe recomendarse como una opción de tratamiento. Los hallazgos sugieren que se debe prestar mayor atención a las características del proceso de tratamiento. Al no incorporar explícitamente tales preferencias en el proceso de toma de decisiones, NICE corre el riesgo de recomendar opciones de tratamiento que son contrarias a las preferencias de la población del Reino Unido.

Systematic review, network meta-analysis and exploratory cost-effectiveness model of randomized trials of minimally invasive techniques versus surgery for varicose veins.

BACKGROUND: A Health Technology Assessment was conducted to evaluate the relative clinical effectiveness and cost-effectiveness of minimally invasive techniques (foam sclerotherapy (FS), endovenous laser ablation (EVLA) and radiofrequency ablation (RFA)) for managing varicose veins, in comparison with traditional surgery. METHODS: A systematic review of randomized clinical trials (RCTs) was undertaken to assess the effectiveness of minimally invasive techniques compared with other treatments, principally surgical stripping, in terms of recurrence of varicose veins, Venous Clinical Severity Score (VCSS), pain and quality of life. Network meta-analysis and exploratory cost-effectiveness modelling were performed. RESULTS: The literature search conducted in July 2011 identified 1453 unique citations: 31 RCTs (51 papers) satisfied the criteria for effectiveness review. Differences between treatments were negligible in terms of clinical outcomes, so the treatment with the lowest cost appears to be most cost-effective. Total FS costs were estimated to be lowest, and FS was marginally more effective than surgery. However, relative effectiveness was sensitive to the model time horizon. Threshold analysis indicated that EVLA and RFA might be considered cost-effective if their costs were similar to those for surgery. These findings are subject to various uncertainties, including the risk of bias present in the evidence base and variation in reported costs. CONCLUSION: This assessment of currently available evidence suggests there is little to choose between surgery and the minimally invasive techniques in terms of efficacy or safety, so the relative cost of the treatments becomes one of the deciding factors. High-quality RCT evidence is needed to verify and further inform these findings.

Clinical effectiveness and cost-effectiveness of minimally invasive techniques to manage varicose veins: a systematic review and economic evaluation.

BACKGROUND: Varicose veins are enlarged, visibly lumpy knotted veins, usually in the legs. Uncomplicated varicose veins can cause major discomfort and some complications. They are part of chronic venous disease (CVD), which is reported to have a substantial negative impact on health-related quality of life (HRQoL). Traditional treatments for varicose veins involve surgical stripping and ligation and liquid sclerotherapy (LS), but can be invasive and painful. New minimally invasive treatments offer an alternative. These treatments typically involve use of laser, radiofrequency or foam sclerosant. They are increasingly widely used and offer potential benefits such as reduced complications, faster recovery, fewer physical limitations and improved quality of life. OBJECTIVE: The aim of this report is to evaluate the clinical effectiveness, safety and cost-effectiveness of the minimally invasive techniques of foam sclerotherapy (FS), endovenous laser ablation (EVLA) and radiofrequency ablation (RFA) in comparison with other techniques, including traditional surgical techniques, LS and conservative management, in the management of varicose veins. DATA SOURCES: A systematic search was made of 11 bibliographic databases of published and unpublished literature from their inception to July 2011: MEDLINE; EMBASE; Cumulative Index to Nursing and Allied Health Literature; The Cochrane Library; Biological Abstracts; Science Citation Index (SCI); Social Sciences Citation Index; Conference Proceedings Citation Index-Science; UK Clinical Research Network; Current Controlled Trials; and ClinicalTrials.gov. REVIEW METHODS: A systematic review of randomised controlled trials (RCTs) to assess the clinical effectiveness of minimally invasive techniques compared with other treatments, principally surgical stripping, in terms of recurrence of varicose veins, retreatment and clinical symptoms, as measured by the Venous Clinical Severity Score (VCSS), pain and quality of life. Network meta-analysis and exploratory cost-effectiveness modelling were performed. RESULTS: The literature search identified 1453 unique citations, of which 34 RCTs (54 papers) satisfied the criteria for the clinical effectiveness review. The minimally invasive techniques reported clinical outcomes similar to surgery. Rates of recurrence were slightly lower for EVLA, RFA and FS, especially for longer follow-up periods; VCSS score was lower for EVLA and FS than for stripping, but slightly higher for RFA; short-term pain was less for FS and RFA but higher for EVLA; higher quality-of-life scores were reported for all evaluated interventions than for stripping. Differences between treatments were therefore negligible in terms of clinical outcomes, so the treatment with the lowest cost appears to be most cost-effective. Our central estimate is that total FS costs were lowest and FS is marginally more effective than stripping. However, this result was sensitive to the model time horizon. Threshold analysis indicated that EVLA and RFA might be considered cost-effective if their costs are equivalent to stripping. These findings are subject to uncertainty on account of the risk of bias present in the evidence base and the variation in costs. LIMITATIONS: The relative clinical effectiveness and cost-effectiveness of the techniques are principally based on rates of post-operative technical recurrence rather than symptomatic recurrence, as this was the reported outcome in all trials. The true proportion of treated individuals who are likely to present with symptoms of recurrence requiring retreatment is therefore not certain. A figure reflecting the likely proportion of treated individuals who would experience symptomatic recurrence requiring retreatment (with its associated costs), therefore, had to be calculated by the authors based on a small number of studies. The findings of this report also need to be verified by data from future trials with longer follow-up and using more standardised outcome measures. CONCLUSIONS: This assessment of the currently available evidence suggests there is little to choose between the minimally invasive techniques in terms of efficacy or cost, and each offers a viable, clinically effective alternative to stripping. FS might offer the most cost-effective alternative to stripping, within certain time parameters. High-quality RCT evidence is needed. Future trials should aim to measure and report outcomes in a standardised manner, which would permit more efficient pooling of their results. STUDY REGISTRATION: PROSPERO number CRD42011001355. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

The cost-effectiveness of supervised exercise for the treatment of intermittent claudication.

BACKGROUND: Supervised exercise (SE) is thought to result in improvements in walking distance and quality of life compared with unsupervised exercise (USE) in people with intermittent claudication. However, the cost-effectiveness of SE is unclear. As a result, many patients are currently unable to access supervised programmes. METHODS: We searched MEDLINE, Embase, Cochrane, and Cinahl databases to identify randomised controlled trials comparing USE with SE in adults with intermittent claudication. A Markov model was developed to estimate costs and quality adjusted life years (QALYs) from an NHS and personal social services perspective. Quality of life was obtained from the included clinical trials. Resource use was modelled on current programmes and unit costs were based on published sources. RESULTS: Depending on estimated rates of compliance, SE was cost-effective in over 75% of model simulations, with an incremental cost-effectiveness ratio of £711 to £1,608 per QALY gained. The model was sensitive to long-term effects of exercise on cardiovascular risk and quality of life. CONCLUSIONS: SE is more cost-effective than USE for the treatment of people with intermittent claudication. Supervised programmes should be made widely available and offered as a first line treatment to people with intermittent claudication.

Cost-effectiveness analysis of enhancements to angioplasty for infrainguinal arterial disease.

BACKGROUND: The aim was to perform an economic evaluation of the cost-effectiveness of endovascular enhancements to percutaneous transluminal balloon angioplasty (PTA) with bail-out bare metal stents for infrainguinal peripheral arterial disease. METHODS: The following interventions were considered: PTA with no bail-out stenting, PTA with bail-out drug-eluting stents, drug-coated balloons, primary bare metal stents, primary drug-eluting stents, endovascular brachytherapy, stent-grafts and cryoplasty. A discrete-event simulation model was developed to assess the relative cost-effectiveness of the interventions from a health service perspective over a lifetime. Populations of patients with intermittent claudication (IC) and critical leg ischaemia (CLI) were modelled separately. Univariable and probabilistic sensitivity analyses were undertaken. Effectiveness was measured by quality-adjusted life-years (QALYs). RESULTS: For both patient populations, the use of drug-coated balloons dominated all other options by having both lower lifetime costs and greater effectiveness. For willingness-to-pay thresholds between £0 and £100,000 per additional QALY, the probability of drug-coated balloons being cost-effective was at least 58.3 per cent for patients with IC and at least 72.2 per cent for patients with CLI. Sensitivity analyses showed that the results were robust to different assumptions regarding the clinical benefits attributable to the interventions. CONCLUSION: The use of drug-coated balloons represents a cost-effective alternative to the use of PTA with bail-out bare metal stents.

A systematic review and economic evaluation of cilostazol, naftidrofuryl oxalate, pentoxifylline and inositol nicotinate for the treatment of intermittent claudication in people with peripheral arterial disease.

BACKGROUND: Peripheral arterial disease (PAD) is a condition in which there is blockage or narrowing of the arteries that carry blood to the legs and arms. It is estimated to affect around 4.5% of people aged between 55 and 74 years within the UK. The most common symptom of PAD is intermittent claudication (IC), characterised by pain in the legs on walking that is relieved with rest. OBJECTIVE: To assess the effectiveness and cost-effectiveness of cilostazol, naftidrofuryl oxalate, pentoxifylline and inositol nicotinate, compared with no vasoactive drugs, for IC due to PAD in adults whose symptoms continue despite a period of conventional management. DATA SOURCE: Electronic bibliographic databases were searched during April to June 2010 (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Conference Proceedings Citation Index, BIOSIS Previews). REVIEW METHODS: Effectiveness outcomes sought were maximal walking distance (MWD), pain-free walking distance (PFWD), ankle-brachial pressure index, cardiovascular events, mortality, adverse events (AEs) and health-related quality of life (HRQoL). A narrative synthesis was provided for all outcomes and a network meta-analysis was undertaken for the walking distance outcomes. A Markov model was developed to assess the relative cost-effectiveness of the interventions from a NHS perspective over a lifetime. The model has three states: vasoactive drug treatment, no vasoactive drug treatment and death. Each 1-week cycle, patients may continue with the drug, discontinue the drug or die. Regression analysis was undertaken to model the relationship between MWD and utility so that a cost per quality-adjusted life-year (QALY) outcome measure could be presented. Univariate and probabilistic sensitivity analyses were undertaken. All costs and outcomes were discounted at 3.5%. RESULTS: Twenty-six randomised controlled trials were identified that met the inclusion criteria for the clinical effectiveness review. There was evidence that walking distance outcomes were significantly improved by both cilostazol and naftidrofuryl oxalate; the 95% credible intervals for the difference from placebo in the logarithm mean change MWD from baseline were 0.108 to 0.337 and 0.181 to 0.762, respectively. It was not possible to include inositol nicotinate within the meta-analysis of MWD and PFWD owing to the lack of 24-month data; however, the shorter-term data did not suggest a significant effect. AEs were minor for all drugs and included headaches and gastrointestinal difficulties. The incidence of serious adverse events (SAEs), including cardiovascular events and mortality, was not increased by the vasoactive drugs compared with placebo; however, most studies had a relatively short follow-up time to address this outcome. HRQoL data were limited. Two studies of limited quality were identified within the review of cost-effectiveness. The de novo model developed suggests that naftidrofuryl oxalate dominates cilostazol and pentoxifylline and has a cost per QALY gained of around £6070 compared with no vasoactive drug. This result is reasonably robust to changes within the key model assumptions. Inositol nicotinate was not included within the main analysis owing to lack of data. However, it is unlikely to be considered to be cost-effective due to its high acquisition cost (£900 vs £100-500 per year for the other drugs). CONCLUSIONS: Naftidrofuryl oxalate and cilostazol both appear to be effective treatments for this patient population, with minimal SAEs. However, naftidrofuryl oxalate is the only treatment that is likely to be considered cost-effective. The long-term effectiveness is uncertain and hence a trial comparing cilostazol, naftidrofuryl oxalate and placebo beyond 24 weeks would be beneficial. Outcomes associated with naftidrofuryl oxalate could also be compared with those associated with supervised exercise programmes and angioplasty.

A prospective randomised controlled trial and economic modelling of antimicrobial silver dressings versus non-adherent control dressings for venous leg ulcers: the VULCAN trial.

OBJECTIVE: To examine the effectiveness and cost-effectiveness of antimicrobial silver-donating dressings for venous leg ulcers compared with simple non-adherent (also known as low-adherent) dressings. DESIGN: A pragmatic, prospective randomised controlled trial (RCT) and cost-effectiveness analysis of silver-donating versus low-adherent dressings in the treatment of venous leg ulcers. A non-randomised observational group was also recruited. SETTING: Primary and secondary care services in the north and south of England (Sheffield and Exeter). PARTICIPANTS: Consenting patients with active ulceration of the lower leg that had been present for a period of greater than 6 weeks. INTERVENTIONS: Patients were randomised to receive either a silver-donating or non-silver low-adherent dressing applied beneath compression bandages or hosiery. The choice of dressing within these groups was left to clinician preference. Evaluation was by clinical assessment, supplemented by evaluation of quality of life and cost-effectiveness. MAIN OUTCOME MEASURES: The primary outcome measure was complete ulcer healing at 12 weeks in the index limb. Secondary measures were costs and quality-adjusted life-years (QALYs), cost-effectiveness, time to healing, and recurrence rate at 6 months and 1 year. RESULTS: In total, 304 participants were recruited to the clinical trial: 213 to the RCT and 91 to the observational arm. Within the RCT 107 were randomised to antimicrobial dressings and 106 to the control dressings. There were no significant differences (p > 0.05) between the two groups for the primary outcome measure of proportion of ulcers healed at 12 weeks (59.6% for silver and 56.7% for control dressings). The overall median time to healing was also not significantly different between the two groups (p = 0.408). A total of 24 patients had recurrent ulcers within 1 year; the recurrence rates of 11.6% (n = 11) for the antimicrobial and 14.4% (n = 13) for the control dressings were not significant. Mean utility valuations for both the EuroQol 5 dimensions (EQ-5D) quality of life questionnaire and Short Form 6 dimensions (SF-6D) utility index showed no differences for either group at 1, 3, 6 or 12 months. Compared with the control group, the antimicrobial group had an incremental cost of 97.85 pounds and an incremental QALY gain of 0.0002, giving an incremental cost-effectiveness ratio for the antimicrobial dressings of 489,250 pounds. Cost-effectiveness modelling of the results of the RCT showed that antimicrobial dressings were not cost-effective. CONCLUSIONS: No significant differences in either primary or secondary end points were found between the use of antimicrobial silver-donating dressings and the control group of low-adherent dressings. Modelling showed that antimicrobial silver dressings were not cost-effective. TRIAL REGISTRATION: Current Controlled Trials ISRCTN72485131.

Endovascular stents for abdominal aortic aneurysms: a systematic review and economic model.

OBJECTIVE: To determine the clinical effectiveness and cost-effectiveness of endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) in patients at varying levels of risk. DATA SOURCES: The following bibliographic databases were searched (2005-February 2007): BIOSIS Previews, CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, ISI Proceedings, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Science Citation Index and Zetoc Conferences. REVIEW METHODS: A systematic review of the clinical effectiveness of EVAR was performed using standard methods. Meta-analysis was employed to estimate a summary measure of treatment effect on relevant outcomes based on intention to treat analyses. A second systematic review was undertaken to identify existing cost-effectiveness analyses of EVAR compared with open surgery and non-surgical interventions. Two new decision models were developed to inform the review. RESULTS: Six RCTs were included in the clinical effectiveness review. Thirty-four studies evaluated the role of patients' baseline characteristics in predicting risks of particular outcomes after EVAR. The majority were based on data relating to devices in current use from the EUROSTAR registry. Compared with open repair EVAR reduces operative mortality (odds ratio 0.35, 95% CI 0.19 to 0.63) and medium-term aneurysm-related mortality (hazard ratio 0.49, 95% CI 0.29 to 0.83) but offers no significant difference in all-cause mortality. EVAR is associated with increased rates of complications and reinterventions, which are not offset by any increase in health-related quality of life. EVAR trial 2 comparing EVAR with non-surgical management in patients unfit for open repair found no differences in mortality between groups; however, substantial numbers of patients randomised to non-surgical management crossed over to receive surgical repair of their aneurysm. The cost-effectiveness systematic review identified six published decision models. Both models considered relevant for the decision in the UK concluded that EVAR was not cost-effective on average compared with open repair at a threshold of 20,000 pounds per quality-adjusted life-year (QALY). Another model concluded that EVAR would be on average more cost-effective than no surgical intervention in unfit patients at this threshold. The Medtronic model concluded that EVAR was more cost-effective than open repair for fit patients at this threshold. The York economic evaluations found that EVAR is not cost-effective compared with open repair on average at a threshold of 30,000 pounds per QALY, with the results very sensitive to model assumptions and the baseline risk of operative mortality. Exploratory analysis to evaluate management options in patients unsuitable for open surgery suggested that the cost-effectiveness of EVAR may be sensitive to aneurysm size and patient's age at operation. Indicative modelling suggests that EVAR may be cost-effective for small aneurysms in some patient groups. Ongoing RCTs will provide further evidence relating to these patients. CONCLUSION: Open repair is more likely to be cost-effective than EVAR on average in patients considered fit for open surgery. EVAR is likely to be more cost-effective than open repair for a subgroup of patients at higher risk of operative mortality. These results are based on extrapolation of mid-term results of clinical trials. Evidence does not currently support EVAR for the treatment of ruptured aneurysms. Further follow-up of the existing UK trials should be undertaken and the relative costs of procedures and devices should be investigated further.

Randomized controlled trial and cost-effectiveness analysis of silver-donating antimicrobial dressings for venous leg ulcers (VULCAN trial).

BACKGROUND: Antimicrobial silver dressings are used beneath graduated compression in the treatment of venous ulceration. There is little information on whether their use is effective. This was a prospective randomized trial and cost-effectiveness analysis of silver-donating versus non-silver low-adherence dressings in the treatment of venous leg ulcers. METHODS: Patients were randomized between the two types of dressing. The primary outcome measure was complete ulcer healing at 12 weeks. Secondary outcomes included time to healing, quality of life and cost-effectiveness. RESULTS: A total of 213 patients were recruited. There was no difference between the dressings in the proportion of ulcers healed at 12 weeks (59.6 per cent for silver and 56.7 per cent for control dressings). Mean utility scores for the EuroQol 5D and Short Form 6D were similar in both groups at 1, 3, 6 and 12 months. Compared with the control group the antimicrobial group had an incremental cost of pounds sterling 97.85 and an incremental quality-adjusted life year gain of 0.0002, giving an incremental cost-effectiveness ratio of pounds sterling 489 250 for the antimicrobial dressings. CONCLUSION: No significant differences were found in either primary or secondary endpoints. There was no evidence to support the routine use of silver-donating dressings beneath compression for venous ulceration. REGISTRATION NUMBER: ISRCTN 72485131 (http://www.controlled-trials.com).

Modelling the long-term cost-effectiveness of endovascular or open repair for abdominal aortic aneurysm.

BACKGROUND: Recent randomized trials have shown that endovascular abdominal aortic aneurysm repair (EVAR) has a 3 per cent aneurysm-related survival benefit in patients fit for open surgery, but it also has uncertain long-term outcomes and higher costs. This study assessed the cost-effectiveness of EVAR. METHODS: A decision model was constructed to estimate the lifetime costs and quality-adjusted life years (QALYs) with EVAR and open repair in men aged 74 years. The model includes the risks of death from aneurysm, other cardiovascular and non-cardiovascular causes, secondary reinterventions and non-fatal cardiovascular events. Data were taken largely from the EVAR trial 1 and supplemented from other sources. RESULTS: Under the base-case (primary) assumptions, EVAR cost 3800 pounds sterling (95 per cent confidence interval (c.i.) 2400 pounds sterling to 5200 pounds sterling) more per patient than open repair but produced fewer lifetime QALYs (mean -0.020 (95 per cent c.i. -0.189 to 0.165)). These results were sensitive to alternative model assumptions. CONCLUSION: EVAR is unlikely to be cost-effective on the basis of existing devices, costs and evidence, but there remains considerable uncertainty.

Randomised clinical trial, observational study and assessment of cost-effectiveness of the treatment of varicose veins (REACTIV trial).

OBJECTIVES: To establish the cost-effectiveness of surgery and sclerotherapy for the treatment of varicose veins. DESIGN: Randomised controlled trials (RCTs) were carried out for conservative treatment, sclerotherapy and surgery for varicose veins. An economic analysis was carried out alongside the randomised trial. Economic modelling was undertaken based on the primary data collection and a literature review (database searches undertaken in April 2000 and updated in March 2001). SETTING: Primary data collection was from a large district general hospital and a teaching hospital both in England over a 2-year period from January 1999. Cost-effectiveness analysis and economic modelling were carried out using an NHS perspective. PARTICIPANTS: A total of 1009 patients were recruited. INTERVENTIONS: Thirty-four patents were randomised in Group 1 (minor varicose veins with no reflux, randomised between conservative treatment and sclerotherapy), 77 in Group 2 (moderate varicose veins with reflux, randomised between surgery and sclerotherapy) and 246 in Group 3 (severe varicose veins with reflux, randomised between conservative treatment and surgery). The remaining 652 patients formed the observational part of the study. MAIN OUTCOME MEASURES: The cost-effectiveness analysis was based on NHS treatment costs for the 2002--3 financial year, and utilities based on the Short Form 6D (SF-6D) preference-based health measure. For the clinical trial, the outcome measures were health-related quality of life (HRQoL) [Short Form with 36 Items (SF-36), EuroQol quality of life questionnaire (EQ-5D), visual analogue scale (VAS) and standard gamble], symptomatic relief, anatomical extent (for which a new classification was developed and validated), patient satisfaction and the incidence of complications. RESULTS: Of the RCTs, only the Group 3 trial was large enough to provide clear results. This showed that surgical treatment produced better results than conservative treatment in terms of HRQoL, symptomatic relief, anatomical extent and patient satisfaction. Clinical outcomes of surgery and sclerotherapy showed significant improvement in the extent of varicose veins, symptomatic and HRQoL parameters. Cost-effectiveness analysis based on the Group 3 trial showed that the surgery produced an estimated discounted benefit of 0.054 quality-adjusted life-year (QALY) over a 2-year period, with an additional discounted cost of pound 387.45, giving an incremental cost-effectiveness ratio (ICER) of pound 7175 per QALY. Economic modelling suggested that surgery produced a still greater benefit when considered with a 10-year time horizon, with an ICER of pound 1936 per QALY. Injection sclerotherapy produced an incremental benefit of approximately 0.044 QALY at a cost of pound 155 when compared with conservative treatment, giving an ICER of pound 3500 per QALY. When surgery was compared with sclerotherapy, surgery produced greater benefit with a lower ICER (showing extended dominance). CONCLUSIONS: Standard surgical treatment of varicose veins by saphenofemoral ligation, stripping and multiple phlebectomies is a clinically effective and cost-effective treatment for varicose veins, with an ICER well below the threshold normally considered appropriate for the funding of treatments within the NHS. Injection sclerotherapy also appears to be cost-effective, but produces less overall benefit, with a higher ICER than surgery for patients with superficial venous reflux. In minor varicose veins without reflux, sclerotherapy is likely to provide a small average benefit with acceptable cost-effectiveness. Research is needed into methods for accurate and acceptable utility evaluations for conditions with relatively minor effect on HRQoL and also for a validated and standardised method of classification for varicose veins.

Cost-effectiveness analysis of surgery versus conservative treatment for uncomplicated varicose veins in a randomized clinical trial.

BACKGROUND: Despite being a common procedure, the cost effectiveness of surgery for varicose veins has not been established. METHODS: Cost-effectiveness analysis was carried out alongside a randomized clinical trial at two vascular units within National Health Service (NHS) hospitals. Some 246 patients with uncomplicated varicose veins and evidence of saphenofemoral or saphenopopliteal reflux were allocated randomly to receive either conservative management or surgical treatment. Incremental cost per quality-adjusted life year (QALY) gained at 24 months following randomization was calculated. RESULTS: Total NHS costs during the 2-year study period were higher for the surgically treated group (733 UK pounds) than for those who had conservative treatment (345 UK pounds). The difference in costs was statistically significant. The mean incremental health gain from surgical treatment at 24 months was 0.083 QALYs, leading to a base-case estimate of 4682 UK pounds per QALY gained. Assuming an implicit threshold maximum willingness-to-pay value of 20 000 UK pounds for a QALY, the probability of surgical treatment for varicose veins falling below this threshold value was 70 per cent. This result was found to be robust to sensitivity analysis. CONCLUSION: For patients with uncomplicated varicose veins and evidence of saphenofemoral or saphenopopliteal reflux, surgical treatment for varicose veins offers a modest health benefit for relatively little additional NHS cost relative to conservative treatment.

Cost-effectiveness of endovascular abdominal aortic aneurysm repair.

BACKGROUND: The rapid introduction of endovascular abdominal aortic aneurysm repair (EVAR) has considerable implications for the management of abdominal aortic aneurysm (AAA). This study was undertaken to determine an optimal strategy for the use of EVAR based on the best currently available evidence. METHODS: Economic modelling and probabilistic sensitivity analysis considered reference cases representing a fit 70-year-old with a 5.5-cm diameter AAA (RC1) and an 80-year-old with a 6.5-cm AAA unfit for open surgery (RC2). Results were assessed as incremental cost-effectiveness ratio (ICER) compared with open repair (RC1) or conservative management (RC2). RESULTS: In RC1 EVAR produced a gain of 0.10 quality-adjusted life years (QALYs) for an estimated cost of 11,449 pound, giving an ICER of 110,000 pound per QALY. EVAR consistently had an ICER above 30,000 pound per QALY over a range of sensitivity analyses and alternative scenarios. In RC2 EVAR produced an estimated benefit of 1.64 QALYs for an incremental cost of 14,077 pound giving an incremental cost per QALY of 8579 pound. CONCLUSION: : It is unlikely that EVAR for fit patients suitable for open repair is within the commonly accepted range of cost-effectiveness for a new technology. For those unfit for conventional open repair it is likely to be a cost-effective alternative to non-operative management. Sensitivity analysis suggests that research efforts should concentrate on determining accurate rates for late complications and reintervention, particularly in patients with high operative risks.

Performance indicators from routine hospital data: death following aortic surgery as a potential measure of quality of care.

BACKGROUND: There is increasing pressure to monitor surgical performance. In the UK, the Department of Health has produced clinical indicators based on routine data to monitor performance. This study analysed whether such data could measure performance in aortic surgery. METHODS: Routine hospital data on postoperative mortality were collected for 1995-1997 in the Trent region. Procedural and diagnostic codes, modes of admission, districts of residence, treatment and specialty data were compared with audit data and the Operating Theatre Information System. RESULTS: Inaccuracies in the Health Resource Group (HRG) codes meant that 21.4 per cent of elective aortic cases (HRG Q02) were probably emergencies and 26 per cent of probable ruptured aneurysms were not coded as a vascular emergency. Case mix and patient selection introduced a bias, apparent between tertiary and district general hospitals. For patients aged over 80 years, two district hospitals undertook no elective aortic surgery; the rate for emergency aortic surgery varied between 16 and 25 per cent in the district hospitals, and was 77 per cent in the tertiary centre. CONCLUSION: Crude mortality rates used as an indicator of performance are subject to bias and distortion owing to the collection of incorrect information, variation in patient selection between hospitals and case-mix differences. There was a considerable variation in selection and outcomes of patients undergoing aortic surgery in this study.

Vascular patients' preferences for local treatment: an application of conjoint analysis.

OBJECTIVES: To investigate whether and to what extent vascular patients are willing to trade expected health outcomes for improvements in non-health benefits, such as the availability of local services, in the provision of peripheral vascular surgery. METHODS: Conjoint analysis was used to elicit patient preferences via a mailed questionnaire. Respondents were asked to consider pairwise descriptions of vascular services described in terms of a number of key attributes and asked to indicate which scenario description they preferred. Multivariate regression analysis was used to estimate the relative importance of the attributes to respondents. RESULTS: Of the 339 patients invited to participate, 161 (47%) returned a completed questionnaire, although 36 (11%) were found to be internally inconsistent and could not be used, leaving 125 (36%) for analysis. An unexpected problem arose with respect to the design of the conjoint analysis questionnaire. Specifically, three of the attributes in the regression model were found to be collinear. The source of this problem, how it was overcome and how it can be avoided in future studies is discussed. The results of the regression analysis indicated that the patients who responded had a preference for local treatment to the extent that they were willing to incur increased risks of perioperative mortality and amputation to receive treatment at their local hospital. These results are discussed in connection with those from a different study which elicited patient preferences for local treatment using a standard gamble technique. CONCLUSIONS: Policy-makers, when considering the potential benefits of regionalising health care, should seek to elicit the preferences of those patients who will be affected by the reorganisation.

Costing vascular surgery: A review of current reporting practice.

OBJECTIVE: The objective of this study was to assess the level of reporting in economic studies in the area of peripheral vascular disease. Adequate reporting of data is necessary to judge the quality of economic studies by means of critical appraisal criteria. METHODS: A systematic review of the journal literature between 1986 and the first half of 1997 was undertaken. Studies that have attempted to estimate the resource consequences of one or more vascular procedure were the focus of the review. The extent of reporting in each study was assessed by using published guidelines. RESULTS: The review identified 30 articles from nine different countries for inclusion in the study. Of these, more than half were published in the last 2(1/2) years of the search period, indicating a recent and rapid growth in economic studies in this area. When subjected to the reporting guidelines, the studies performed rather poorly overall. CONCLUSIONS: Although the vascular studies can be criticized for inadequate reporting of economic data, it appears from the limited evidence from elsewhere that inadequate reporting is a problem in other clinical areas. In view of the importance of reporting to the ability to critically assess studies-and thus separate the "good" from the "bad"-there is a need for reporting to improve future published studies.