Background Patients with burn injuries may receive a skin graft to achieve healing in a timely manner. However, in around 7% of cases, the skin graft is lost (fails to attach to the wound site) and a re-grafting procedure is necessary. It has been hypothesised that low-friction (smooth, more slippery) bedding may reduce the risk of skin-graft loss. A before and after feasibility study comparing low-friction with standard bedding in skin-grafted patients was conducted in order to collect proof of concept data. The resulting relative risk on the primary outcome (number of patients with skin graft failure) for the non-randomised study provided no evidence of effect but had a large standard error. The aim of this study is to see if an appropriately powered randomised control trial would be worthwhile. Methods A probabilistic decision-analytic model was constructed to compare low-friction bedding to standard care in a population of burn patients who have undergone skin grafting. Results from the before and after study were used as model inputs. The sensitivity of results to bias in the relative risk of graft loss was conducted. Low-friction bedding is considered optimal if expected incremental net benefit (INB) is positive. Uncertainty is assessed using cost-effectiveness acceptability curves. Expected Value of Perfect Partial Information (EVPPI) provides an upper bound for the potential net health benefits of new research for given model input. Results At a willingness to pay threshold of £20,000 per QALY, INB = £151 (95% Credible Interval (CrI) -142 to 814), marginally favouring low-friction bedding but with high uncertainty (probability of being cost-effective 70.5%). Expected value of perfect information (EVPI) per patient was £20.29, which results in a population EVPI of £174,765 over a 10-year lifetime for the technology (based on 1000 patients per year who would benefit from the intervention). The parameter contributing most to the uncertainty was the inpatient care cost, i.e. information that could be obtained from the audit of practice and without an expensive trial. These findings were robust to a wide-range of assumptions about the potential bias due to the observational nature of the comparative evidence. Conclusions Our study results suggest that an RCT (randomised controlled trial) is unlikely to be worthwhile, but there may be value in a study to estimate the re-graft rates and associated costs in this population.

中文翻译：

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烧伤患者植皮后低摩擦环境的成本效益和信息分析价值。


背景 烧伤患者可以接受植皮手术以实现及时愈合。然而，在大约 7% 的情况下，皮肤移植物会丢失（无法附着到伤口部位），因此需要重新移植手术。据推测，低摩擦（光滑、更滑）的垫层可以降低植皮损失的风险。为了收集概念验证数据，进行了一项前后可行性研究，比较了植皮患者的低摩擦与标准床上用品。非随机研究的主要结果（皮肤移植失败的患者数量）的相对风险没有提供效果证据，但有很大的标准误差。本研究的目的是看看是否值得进行适当的随机对照试验。方法 构建概率决策分析模型，对接受植皮的烧伤患者群体进行低摩擦床上用品与标准护理的比较。研究前后的结果用作模型输入。研究了结果对移植物丢失相对风险偏倚的敏感性。如果预期增量净效益 (INB) 为正，则低摩擦垫层被认为是最佳选择。使用成本效益可接受性曲线评估不确定性。完美部分信息的期望值 (EVPPI) 为给定模型输入的新研究的潜在净健康效益提供了上限。结果 在每个 QALY 的支付意愿为 20,000 英镑的门槛下，INB = 151 英镑（95% 可信区间 (CrI) -142 至 814），略微偏向于低摩擦床上用品，但具有很高的不确定性（具有成本效益的概率为 70.5%） ）。每个患者的完美信息预期价值 (EVPI) 为 20 英镑。29，这导致该技术在 10 年生命周期内的群体 EVPI 为 174,765 英镑（基于每年 1000 名患者将从干预中受益）。对不确定性影响最大的参数是住院护理成本，即可以从实践审核中获得的信息，而无需进行昂贵的试验。由于比较证据的观察性质，这些发现对于有关潜在偏差的各种假设都是稳健的。结论 我们的研究结果表明，RCT（随机对照试验）不太值得，但估计该人群的再移植率和相关成本的研究可能有价值。