4 Committee discussion
4.1 The committee noted that Stanirowski et al. 2016a was a well-performed randomised controlled trial (RCT) with a limited risk of bias. The results showed a statistically significant reduction in surgical site infection (SSI) 14 days after caesarean section with Leukomed Sorbact compared with standard dressings. The committee and clinical experts discussed the relatively low rate of systemic antibiotic use in women who had SSI in this study. The committee considered that this was likely to be explained by the infections being relatively mild. The clinical experts stated that intravenous antibiotics were only needed for treating the most severe SSIs. The committee concluded that using Leukomed Sorbact reduced the rate of SSI after caesarean section compared with standard dressings.
4.2 In the prospective non-randomised Bua et al. 2017 study there were fewer SSIs with Leukomed Sorbact compared with standard dressings at 5 to 7 days and at 30 days. Although the number of people included in the Totty et al. 2019 pilot RCT was relatively small, there were fewer SSIs in those who had Leukomed Sorbact. The committee recognised the limitations of the evidence. But it concluded that the study results and the plausibility of the clinical benefit for this group was sufficient to support the use of Leukomed Sorbact after vascular surgery. It welcomed further research in this area.
The evidence does not support a broader recommendation to use Leukomed Sorbact in all types of surgery
4.3 No evidence was presented to support the use of Leukomed Sorbact in surgery other than caesarean section and vascular surgery. It was noted that Leukomed Sorbact could potentially be particularly useful in plastic surgery and breast surgery, which involve subcutaneous dissection. One clinical expert stated that Leukomed Sorbact is being used after gynaecological surgery at their hospital, but no data are currently available on this use. The committee concluded that the current evidence could not be extrapolated to support the use of Leukomed Sorbact after all types of surgery. It also concluded that it would welcome further research on the use of Leukomed Sorbact in other types of surgery.
4.4 Comments from clinical experts about the clinical benefits of Leukomed Sorbact were positive, noting that it seemed to reduce SSI and was easy to use. The clinical experts were broadly optimistic that Leukomed Sorbact may be useful for other types of surgery.
4.5 In Stanirowski et al. 2016a, developing SSI led to an increase in mean hospital stay of 8.2 days in the control group. Women with SSI in the Leukomed Sorbact group had more outpatient visits than women with SSI in the control group (4.6 per person compared with 2.9 per person, respectively). This was a secondary analysis in a small subgroup of women. The clinical experts explained that reducing SSI may have additional benefits, such as new mothers being able to care for their babies and a positive effect on postnatal mental health. The committee concluded that reducing the incidence of SSI after caesarean section was likely to reduce the need for prolonged hospital stays and enhance recovery.
4.6 The clinical experts reported that people using Leukomed Sorbact had found it to be comfortable and had positive feedback. Unlike the battery-powered PICO, it can be worn while showering and does not make any noise.
4.7 The clinical experts noted only 1 report of contact dermatitis after the use of Leukomed Sorbact. The external assessment centre (EAC) identified 1 adverse event registered with the US Food and Drug Administration, in which a person who had a total knee replacement developed a chemical burn after using Leukomed Sorbact. About 1 month after surgery, the person attended the emergency department because of a chemical burn with eschar over the surgical site. The eschar was surgically removed, and the person was discharged after 2 days. This was described in the report as a 'device malfunction' but no other details were reported. The company's submission included an observational study in a poster presentation (Coldwell et al. 2014). In this study there were 2 hypersensitivity reactions to the adhesive in 55 people who had Leukomed Sorbact in an Australian primary care setting.
4.8 The Stanirowski et al. 2016a and 2016b studies, which investigated the use of Leukomed Sorbact after caesarean section, were both done in Poland. The clinical experts advised, however, that the care pathway and outcome measures reported in these studies were relevant to an NHS setting. The 2 studies investigating the use of Leukomed Sorbact for vascular surgery (Totty et al. 2019 and Bua et al. 2017) were done in the UK. The committee concluded that the evidence was relevant to the NHS.
Most wounds from vascular surgery and caesarean section are expected to have low to moderate exudate
4.9 Leukomed Sorbact is indicated when a wound is expected to have low to moderate exudate. The clinical experts advised that this would be most caesarean section or vascular surgery wounds. They also explained that people with wounds at risk of high exudate could usually be identified at the time of surgery and would not have Leukomed Sorbact dressings.
The company's cost model is appropriate for caesarean section and vascular surgery but not for other types of surgery
4.10 The committee agreed with the EAC that the company's cost model was appropriate for analysing the costs of using Leukomed Sorbact after caesarean section and vascular surgery. It noted that only small adjustments were needed. The committee also agreed with the EAC that cost modelling was inappropriate for an all surgery group because there was no evidence to support the benefits of Leukomed Sorbact for all types of surgery.
4.11 The EAC's base-case analysis showed that, compared with standard dressings, using Leukomed Sorbact is cost saving by:
£107.43 per person after caesarean section
£17.82 per person after vascular surgery.
The standard surgical dressing used as the comparator in the cost modelling was the Opsite Post‑OP dressing, the best-selling vapour-permeable adhesive film and absorbent sterile pad dressing. The clinical experts confirmed that this standard dressing was widely used in NHS practice.
The sources for the baseline risk of SSI and the costs of treating SSI after caesarean section and vascular surgery are appropriate
4.12 In the company's model, baseline SSI risks for different surgical indications were taken from NHS England or NHS Wales data. The Leukomed Sorbact SSI risk was taken from the pooled results of the clinical studies (Stanirowski et al. 2016a and 2016b for caesarean section; Bua et al. 2017 and Totty et al. 2019 for vascular surgery). The EAC considered the data sources for these inputs appropriate. The cost of SSI in caesarean section was taken from Jenks et al. 2014. The cost of SSI in vascular surgery was taken from an unpublished study (York Health Economics Consortium 2020) but the EAC considered that costs from Jenks et al. 2014 were more appropriate. The committee accepted that these sources were appropriate.
4.13 The company's sensitivity analyses varied the rate of SSI and the costs of Leukomed Sorbact and the comparator. Leukomed Sorbact remained cost saving in all these analyses. The company did 1‑way sensitivity analysis on the cost per SSI episode, varying the cost estimates within their 95% confidence intervals:
For caesarean section, the base-case SSI episode cost was £4,048 and the breakeven point was £350.
For vascular surgery, the base-case SSI episode cost was £3,427 and the breakeven point was £2,000.
A second sensitivity analysis investigated the effect of reducing the standard dressing cost by 50% and increasing the cost of Leukomed Sorbact by 100%, or both. For both caesarean section and vascular surgery Leukomed Sorbact remained cost saving.
4.14 The company did a scenario analysis, varying the relative risk reduction by plus or minus 25%:
For caesarean section, the base-case SSI risk was 4.35%, with a relative risk reduction of 67% and an incremental cost per person of -£107.43. The breakeven point for relative risk reduction was 6%.
For vascular surgery, the base-case SSI risk was 2.5%, with a 42% relative risk reduction and an incremental cost per person of -£23.54. The breakeven point for relative risk reduction was 13%.
4.15 The EAC did threshold analyses for cost savings from using Leukomed Sorbact after caesarean section and vascular surgery. The breakeven points were estimated for key values in the cost model. For caesarean section:
baseline SSI risk: base case 4.35%, breakeven point 0.39%
relative risk reduction in SSI: base case 67%, breakeven point 6%
SSI episode cost: base case £4,048, breakeven point £362.
For vascular surgery:
baseline SSI risk: base case 2.5%, breakeven point 0.93%
relative risk reduction in SSI: base case 42%, breakeven point 16%
SSI episode cost: base case £2,072, breakeven point £1,004.
Leukomed Sorbact is cost saving across a wide range of SSI costs, device costs, comparator costs and relative risk reduction
4.16 There were wide margins for cost neutrality and cost savings. This satisfied the committee that even with some uncertainty around the strength of the clinical evidence, Leukomed Sorbact was highly likely to be cost saving in caesarean section and vascular surgery.
4.17 The committee noted that a multicentre RCT on the use of Leukomed Sorbact in vascular surgery is being proposed. It welcomed this, as well as the collection of real-world evidence. Also, the committee encouraged further research on using Leukomed Sorbact for a wider range of surgical indications, as well as investigating the effect of Leukomed Sorbact on people with different baseline SSI risks.