moorLDI2-BI: a laser doppler blood flow imager for burn wound assessment

The evidence comprised a cost analysis to assess the costs and savings to the NHS from use of the moorLDI2-BI for the assessment of burn wounds of intermediate depth, as described in the manufacturer's submission. The costs and savings from using the moorLDI2-BI in addition to clinical evaluation were compared with those from using clinical evaluation alone. The cost analysis balanced the additional equipment and staff costs of burn wound assessment with the moorLDI2-BI against the cost benefits from earlier more appropriate treatment decisions based on information from moorLDI2-BI images.

The cost model assumed 10,000 patients, based on Enoch et al. (2009), admitted each year to 28 'burns centres' in England and Wales. For the purposes of the cost model the term 'burns centre' encompasses burns centres, units and facilities (as defined in the National Burn Care review). 

The cost model assumed that 70% of the admitted patients were likely to have intermediate burn wounds and be scanned. To calculate a per patient cost in the base case, each burns centre was assumed to have one imager with annual staff training costs of £5,160. Nurse scanning time per patient was 1 hour and clinician time per patient for interpreting results was 15 minutes. The cost savings included were based on a reduction of 17% in the number of skin graft operations and a 2-day reduction in the length of hospital stay. These parameter values were based on evidence from clinical studies. In the model the cost per hour for an operation to treat burn wounds was £4,593, based on the figures presented in Hemington-Gorse et al. (2009). Expert advice to the external assessment centre was that this hourly cost was high, so it derived a lower figure of £2,043, this has been adjusted for inflation to £2,319 per hour. [2017]

A range of scenario analyses were done, including best- and worst-case scenarios using the ranges for the proportion of patients scanned, number of bed days saved and operating time. Additional analyses were done by the external assessment centre to assess the impact of changing the hourly cost for an operation to £2,043, this has been adjusted for inflation to £2,319. [2017]

The cost saving per patient scanned from using the moorLDI2-BI in addition to clinical evaluation compared with clinical evaluation alone for the base case was £1,281 for the purchase option and £1,274 for the lease option (both based on an hourly cost of £2,043 per operation). The worst-case scenario for the purchase option, based on 2011 prices resulted in a cost saving of £734 per patient and the best-case scenario resulted in a saving of £2,860 per patient scanned. All analyses presented in the assessment report showed that the total cost saving from reducing length of hospital stay and number of operations was greater than the costs associated with the purchase and operation of the moorLDI2-BI. [2017]

An area of uncertainty in the cost analyses was the impact on the cost per patient scanned of the assumption that all patients scanned would achieve on average a 2-day reduction in length of hospital stay. An additional analysis was undertaken that modelled the assumption that there was no length of stay reduction from using the moorLDI2-BI. This demonstrated that the moorLDI2-BI would still achieve a cost saving of £159 per patient scanned when a 17% reduction in operations was assumed (based on the purchase option and an hourly cost of £2,043 per operation).

The committee considered the implications of purchasing the moorLD12 BI for use in units or facilities, which may deal with smaller numbers of burns patients and with less specialised resources. All units and facilities should have access to a trained specialist to interpret the scan, and to break even, the cost model for the base case showed a minimum of 21 burns patients a year needed to be admitted to a burns centre, of which 70% would be scanned.

The committee was informed that the device had been available to the NHS for a number of years and was already used routinely in some burn care services.

The base case in the manufacturer's submission included costs of 1 hour scanning time and 1 hour skin graft procedure associated with an average intermediate burn. The committee was advised that 30 minutes scanning time is more appropriate for burn wounds requiring a 1‑hour skin grafting procedure. Using this time for a scan, the cost saving per patient scanned in the base case was recalculated as £1,254 for the purchase option and £1,270 for the lease option.

The cost analysis focused on cost savings associated with inpatient care. The committee was advised that additional savings, including avoidance of hospital admission, might be obtained by using the device as an aid to clinical decision-making for outpatients with small burns of uncertain depth.

The time horizon for the cost analysis was the initial period of hospitalisation, and no longer-term cost consequences were included. The manufacturer described but did not quantify the longer-term cost benefits from improved treatment decisions. Avoiding unnecessary grafting or making earlier decisions to graft could avoid the need for long durations of prophylactic anti-scar therapy or any therapy. Anti-scar therapy includes fitting pressure garments and follow-up hospital appointments.