Clinical effectiveness and cost-effectiveness of foam sclerotherapy, endovenous laser ablation and surgery for varicose veins: results from the Comparison of LAser, Surgery and foam Sclerotherapy (CLASS) randomised controlled trial.

Abstract

BACKGROUND: Foam sclerotherapy (foam) and endovenous laser ablation (EVLA) have emerged as alternative treatments to surgery for patients with varicose veins, but uncertainty exists regarding their effectiveness in the medium to longer term. OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of foam, EVLA and surgery for the treatment of varicose veins. DESIGN: A parallel-group randomised controlled trial (RCT) without blinding, and economic modelling evaluation. SETTING: Eleven UK specialist vascular centres. PARTICIPANTS: Seven hundred and ninety-eight patients with primary varicose veins (foam, n = 292; surgery, n = 294; EVLA, n = 212). INTERVENTIONS: Patients were randomised between all three treatment options (eight centres) or between foam and surgery (three centres). PRIMARY OUTCOME MEASURES: Disease-specific [Aberdeen Varicose Vein Questionnaire (AVVQ)] and generic [European Quality of Life-5 Dimensions (EQ-5D), Short Form questionnaire-36 items (SF-36) physical and mental component scores] quality of life (QoL) at 6 months. Cost-effectiveness as cost per quality-adjusted life-year (QALY) gained. SECONDARY OUTCOME MEASURES: Quality of life at 6 weeks; residual varicose veins; Venous Clinical Severity Score (VCSS); complication rates; return to normal activity; truncal vein ablation rates; and costs. RESULTS: The results appear generalisable in that participants' baseline characteristics (apart from a lower-than-expected proportion of females) and post-treatment improvement in outcomes were comparable with those in other RCTs. The health gain achieved in the AVVQ with foam was significantly lower than with surgery at 6 months [effect size -1.74, 95% confidence interval (CI) -2.97 to -0.50; p = 0.006], but was similar to that achieved with EVLA. The health gain in SF-36 mental component score for foam was worse than that for EVLA (effect size 1.54, 95% CI 0.01 to 3.06; p = 0.048) but similar to that for surgery. There were no differences in EQ-5D or SF-36 component scores in the surgery versus foam or surgery versus EVLA comparisons at 6 months. The trial-based cost-effectiveness analysis showed that, at 6 months, foam had the highest probability of being considered cost-effective at a ceiling willingness-to-pay ratio of £20,000 per QALY. EVLA was found to cost £26,107 per QALY gained versus foam, and was less costly and generated slightly more QALYs than surgery. Markov modelling using trial costs and the limited recurrence data available suggested that, at 5 years, EVLA had the highest probability (≈ 79%) of being cost-effective at conventional thresholds, followed by foam (≈ 17%) and surgery (≈ 5%). With regard to secondary outcomes, health gains at 6 weeks (p < 0.005) were greater for EVLA than for foam (EQ-5D, p = 0.004). There were fewer procedural complications in the EVLA group (1%) than after foam (7%) and surgery (8%) (p < 0.001). Participants returned to a wide range of behaviours more quickly following foam or EVLA than following surgery (p < 0.05). There were no differences in VCSS between the three treatments. Truncal ablation rates were higher for surgery (p < 0.001) and EVLA (p < 0.001) than for foam, and were similar for surgery and EVLA. CONCLUSIONS: Considerations of both the 6-month clinical outcomes and the estimated 5-year cost-effectiveness suggest that EVLA should be considered as the treatment of choice for suitable patients. FUTURE WORK: Five-year trial results are currently being evaluated to compare the cost-effectiveness of foam, surgery and EVLA, and to determine the recurrence rates following each treatment. This trial has highlighted the need for long-term outcome data from RCTs on QoL, recurrence rates and costs for foam sclerotherapy and other endovenous techniques compared against each other and against surgery. TRIAL REGISTRATION: Current Controlled Trials ISRCTN51995477. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 27. See the NIHR Journals Library website for further project information