5.1 The main aspects of the cost impact evidence for treatment of in-stent restenosis with SeQuent Please balloon catheters are presented below. Full details of all cost impact evidence and modelling considered by the Committee are available in the assessment report.
5.2 The manufacturer submitted a Markov model to assess the costs and consequences of use of SeQuent Please balloon catheter compared with paclitaxel-eluting stent. Costs included those associated with buying the balloon catheter, staff and other costs associated with the procedure, necessary medication, serious complications and survival from the perspective of the NHS and Personal Social Services. The model used a 1-year time horizon, with monthly Markov cycles and applied a half-cycle correction. The model used a 'within-trial' approach, using the PEPCAD II trial with a 12-month time horizon. There was no extrapolation from this short-term time horizon to the long-term, therefore longer term cost impact could not be assessed.
5.3 All of the costs for the procedures and adverse events were taken from the National Tariff 2010–2011. The External Assessment Centre considered that this approach was appropriate. The cost of a percutaneous coronary intervention was based on the HRG code EA31Z which refers to PCI involving 0–2 stents. The percutaneous coronary intervention cost was applied similarly for both treatment arms, with a cost differential of £200 associated with the device being added to the SeQuent Please balloon catheter arm. The External Assessment Centre considered that more information justifying the £200 price differential needed to be provided and although an increased price differential of £300 was investigated, reducing the potential cost saving by just over £100, further sensitivity analysis around the price differential would have been informative.
5.4 The cost of antiplatelet therapy using clopidogrel was applied per cycle (that is, every month), based on prices derived from 'Prasugrel for the treatment of acute coronary syndromes with percutaneous coronary intervention' (NICE technology appraisal guidance 182), and applied for the corresponding durations: 3 months for SeQuent Please balloon catheter and 12 months for paclitaxel-eluting stent. Total costs of clopidogrel were £108 and £430, respectively. The External Assessment Centre questioned whether these treatment durations reflected real-world practice because, based on the PEPCAD II trial, the percentages of patients taking clopidogrel after SeQuent Please balloon catheter treatment were 29% at 6 months and 18% at 12 months, and after paclitaxel-eluting stent were 65% at 6 months and 42% at 12 months. These differing treatment durations and proportions of patients were not incorporated in the model or addressed in the sensitivity analysis. The External Assessment Centre carried out additional sensitivity analysis assuming 7 months of clopidogrel therapy in the SeQuent Please balloon catheter arm and 8 months in the paclitaxel-eluting stent arm. This changed the potential saving to £187.
5.5 The manufacturer's submission stated that the model used transition probabilities based on the rates of target lesion revascularisation or target vessel revascularisation. These were proposed by the manufacturer to be the main cost drivers, however, a cost model using target lesion revascularisation was not presented in the manufacturer's submission. The transition probabilities were derived from the PEPCAD II trial, in addition to two studies on coronary artery bypass grafting for probabilities related to bleed-related mortality. In the base case it was assumed that transition probabilities did not vary according to time.
5.6 Probabilistic sensitivity analysis was not submitted by the manufacturer. Deterministic sensitivity analysis was undertaken, which investigated the following model parameters:
target vessel revascularisation rates
anti-platelet therapy (clopidogrel) duration
cost of SeQuent Please balloon catheter
cost of target vessel revascularisation and myocardial infarction
time dependence for events (that is, time-dependent transition probabilities).
5.7 The sensitivity analysis identified the key drivers of the results to be target vessel revascularisation rates, co-medication costs and initial revascularisation costs.
5.8 The cost model submitted by the manufacturer, using target vessel revascularisation rates in the base case, reported an average per-patient cost over the 1-year horizon of £4134 for the SeQuent Please balloon catheter treatment arm and £4873 for the paclitaxel-eluting stent arm. Therefore SeQuent Please balloon catheter was associated with a cost saving of £739 per patient compared with paclitaxel-eluting stent.
5.9 Target vessel revascularisation and target lesion revascularisation were considered by the Committee to be legitimate clinical outcomes for trial analysis. The cost impact of an intervention resulting in either target vessel revascularisation or target lesion revascularisation is comparable as both involve a repeat procedure. The External Assessment Centre identified that the target vessel revascularisation rates used in the base-case model were obtained from different study populations so considered it appropriate to construct a model based on target lesion revascularisation rates from the PEPCAD II trial at 12-month follow-up. Target lesion revascularisation rates of 6% (4/65) for SeQuent Please balloon catheter and 15% (10/63) for paclitaxel-eluting stent were applied. Further details of this cost model are available in the External Assessment Centre's supplementary report.
5.10 The cost model by the External Assessment Centre using a target lesion revascularisation instead of target vessel revascularisation parameter reported an average per-patient cost over the 1-year time horizon of £3856 for the SeQuent Please balloon catheter treatment arm and £4323 for the paclitaxel-eluting stent arm. Therefore SeQuent Please balloon catheter was associated with a cost saving of £467 per patient compared with paclitaxel-eluting stent. This is the cost saving quoted in section 1.1.
5.11 The results reported in the manufacturer's submission indicated that SeQuent Please balloon catheter is likely to be cost-saving over the 1-year time horizon for patients with in-stent restenosis. These findings are sensitive to target vessel revascularisation rates, co-medication costs and initial revascularisation costs.
5.12 In the revised cost model developed by the External Assessment Centre and based on target lesion revascularisation costs, SeQuent Please remained cost saving when event rates were varied ± 20%.
5.13 The Committee noted that cost data were restricted to the comparison of SeQuent Please balloon catheter and paclitaxel-eluting stent in patients with in-stent restenosis, over a 1-year time horizon.
5.14 The Committee noted that although only one comparator (paclitaxel-eluting stent) was used in the cost model, this was likely to be the most relevant comparator for this technology, and was therefore appropriate for the model.
5.15 The Committee was advised by the External Assessment Centre that the use of target lesion revascularisation rates from the two arms of the same trial population in the base-case model was more robust than the use of target vessel revascularisation data from different trial populations. The Committee considered the cost saving using target lesion revascularisation instead of target vessel revascularisation to be more robust. On this basis, SeQuent Please balloon catheter was associated with a cost saving of £467 per patient compared with paclitaxel-eluting stent. This is quoted in section 1.1.
5.16 The Committee considered the evidence on clopidogrel duration included in the model. It noted in particular the sensitivity analysis carried out by the External Assessment Centre. Even when the assumptions on the duration of clopidogrel therapy that were most unfavourable to SeQuent Please balloon catheter were applied, it remained cost saving.