Real World Burn Care Trends Survey

A survey was developed and administered to 14 burn surgeons, representing a 10% sample of U.S. burn centers (n=136) nationally between June and December 2019. Details on the methodology and outcomes of the survey are published elsewhere. The survey provided information on existing assumptions and data inputs (based on BEACON inputs) and prompted the burn centers to update this information based on their own burn center practices. The survey collected information across several domains, including: burn center characteristics; burn patient characteristics including number of patients, TBSA and depth of burn; aggregate number of types of procedures; and resource use such as operating room/surgery time, length of stay (LOS), and dressing changes. Additionally, specific costs, resource use and procedure trends were also captured in burns with TBSA ≤20% to understand differences in care pathways for less severe burns.

Data for all centers were combined, summaries were developed and compared using descriptive statistics, based upon averages for all quantitative responses. Comparisons of key survey outcomes such as number of procedures and costs were made across burn center characteristics (i.e., region, size) to understand variations in treatment patterns and outcomes from the national averages over time. Benchmark estimates were then integrated into the BEACON model to re-evaluate the impact of ASCS considering the latest assumptions of SOC from burn centers.

BEACON model

Structure

The CEM within BEACON evaluated a single inpatient stay for the management of a severe burn from a burn center perspective. The model received patient characteristics as input and then utilized linked, sequential decision trees across multiple treatment pathway modules including wound assessment, debridement/excision, temporary coverage, definitive closure and rehabilitation, to estimate the clinical and economic outcomes associated with each phase of care, and overall, during inpatient care. The budget impact model (BIM) was built on the CEM to capture the impact of interventions on costs and patient outcomes for a burn center overall, accounting for key drivers specific to the burn center, such as the expected patient mix by burn depth, TBSA burned, and other individual patient characteristics. The model compared costs for the two treatment pathways (with and without the use of ASCS) to isolate the likely shift in costs related to ASCS use. The model also allows users to select conservative approximation vs. NBR predictive equations methods to calculate number of procedures for SOC only 5, 14. The conservative approximation method assumes a single conventional autografting procedure with STSG for patients with TBSA ≤ 20% and two conventional autografting procedures with STSG for patients with TBSA > 20%whereas the NBR predictive equations estimate the number of procedures to obtain definitive closure via conventional autografting with STSG (by burn depth and TBSA) by using ICD-9 procedure codes to identify conventional procedures for SOC within the NBR data. An overview of the burn care pathway and core assumptions involved in the models are detailed in the original BEACON publication by Kowal S et al 5.

Patient profile

The target population for the model includes adults (average age of 42 years) having severe burns with TBSA ≥ 10% who receive inpatient care, where DPT and FT/mixed-depth burns are eligible for ASCS.

Clinical Inputs

Clinical inputs used in the original BEACON model were supplemented with latest survey data specifically for phases impacted by ASCS such as definitive closure. Key clinical inputs obtained from the survey are reported in Table 1.

Cost Inputs

Key cost elements obtained from the survey include bed cost per day, anesthesiology cost per patient and cost of burn surgery operating room (OR) time per hour. Other cost inputs for the model remained same as the original BEACON model costs which were obtained in 2017. All unit costs were adjusted to 2020 USD and are reflective of average costs reported by burn centers. These costs are reported in Table 2

Table 2

Provider resource use element	Unit	Cost (US 2020)
Cost per day for burn patients	per day	$8,607.37
Cost per day for burn patients (TBSA: 10%, 20%)	per day	$7,775.65
Burn surgery operating room time	per hour	$4,985.89
Anesthesiology	per patient	$5,338.89
Anesthesiology (FT/mixed-depth: TBSA 10%, 20%)	per patient	$4,843.82
Anesthesiology (DPT: TBSA 10%, 20%)	per patient	$4,841.04

Analyses

Cost-effectiveness analysis

The BEACON model is customizable and can be used with individual burn center data. However, the results presented are based on averages obtained from sample burn centers that participated in the survey and are reported for adult patients (average age of 42 years) with TBSA 10%, 20%, 30%, and 40% for DPT and FT/mixed-depth burns, which were controlled for comorbidities obtained from NBR data. The analysis was conducted using the NBR predictive equations method. Overall patient characteristics remained the same for DPT and FT/mixed-depth burns, however the model inputs were varied as reported in Table 1, Table 2 to account for the impact of wound depth on LOS and amount of donor skin harvested (and associated impact on surgery time) (Table 3 ). One-way sensitivity analysis (OWSA) was also conducted for each patient profile.

Table 3

Details of patient profiles for the cost-effectiveness modela
	TBSA
Patient characteristics	10%		20%		30%		40%
Female (%)	26%		23%		27%		27%
Age (years)	42		42		42		42
BSA (cm2)	19,808		19,856		19,788		19,783
Size of burn (c m2)	1,981		3,971		5,936		7,913
Comorbidities
Inhalation injury (%)	4%		9%		13%		25%
Hospital-acquired infection (HAI) (%)	1%		3%		4%		9%
Other infection (%)	2%		5%		4%		5%
Diabetes (%)	6%		6%		3%		4%
Details of default settings for a burn center with 341 patients annually
		Full-thickness or mixed depth No. Patients (%)		Deep partial-thickness No. Patients (%)		Superficial partial-thicknessb No. Patients (%)
Wound depth distribution		103 (30.2%)		96 (28.3%)		141 (41.5%)
Proportion of burns
TBSA>40% (average 48%)		15 (15%)		9 (9%)		7 (5%)
TBSA 21-40% (average 28%)		33 (32%)		25 (26%)		32 (23%)
TBSA 10-20% (average 15%)		55 (53%)		62 (62%)		102 (72%)

^aSource:Inputs for CEM based on analysis of NBR data from BEACON model

Budget impact analysis

Average number of patients treated annually in a hypothetical burn center (n = 341) was used to estimate the budget impact. Patient characteristics for FT/mixed-depth and DPT burns such as wound distribution across TBSAs and average age were obtained from our survey. The same data for superficial partial-thickness (SPT) burns were obtained from the original BEACON NBR data. Data such as gender, comorbidities were from NBR data consistent with CEM. The target CEM profiles described above highlight the range in outcomes across potential patient and burn types whereas the BIM considers the relative mix of TBSA ranges. Table 3 T

Shift in trends of key model inputs: Survey (2019) vs NBR v8.0 (2002-2011)/physician survey (2017)

Based on the average patient distribution from the sample burn centers across burn depths, there is a significant increase in the proportion of severe burns treated in an inpatient setting (51% increase in FT/mixed-depth burns and 5% increase in DPT burns) compared to 2011. More SPT burns are now being treated in an outpatient setting (22% decrease in SPT burns treated inpatient compared to 2011). Survey data also showed that FT/mixed depth and DPT burns > 40% TBSA remained relatively stable since 2011 (from 15% to 15.5% in FT; from 8% to 8.6% in DPT). However, TBSA 21-40% decreased slightly (from 39% to 32% in FT; from 34% to 26% in DPT) and TBSA 10-20% burns have increased (from 46% to 52.5% in FT; from 58% to 65.12% in DPT) Figure 1.

Figure 1

Since 2017, there has been an overall increase in inpatient bed cost per day (23% increase for all patients and 11% increase for patients with TBSA ≤20%), OR cost per hour (30% increase) and anesthesiology costs per patient (93% increase for all patients; 75% increase for FT/mixed-depth and DPT patients with TBSA ≤20%) Figure 2.

Figure 2

There is also a significant decreasing trend since 2017 in the average number of autograft procedures (30% decrease for FT/mixed depth burns and 28% decrease for DPT burns). The average surgical time for graft and donor site remained same in FT/mixed-depth burns but there is a slight decrease of 6% in average surgical time for graft and donor site among DPT burns Figure 3. Detailed inputs from NBR v8.0 or the 2017 cost data for comparison are available in BEACON publication by Kowal S et al.5

Figure 3

Cost-effectiveness analysis

ASCS use was cost-saving for both FT/mixed-depth and DPT burns across all TBSA ranges. The major cost saving factor was the reduced number of autografting procedures due to ASCS use, which resulted in shorter LOS. LOS reductions are likely due to the reduced need for donor skin harvesting and associated morbidities. In both, FT/mixed depth and DPT burns, cost-savings increased notably with increase in burn size due to overall reduction in the number of operations, dressing time, and associated costs compared to SOC. The number of SOC autograft procedures increased with larger burn size, leading to a greater difference in costs compared to ASCS. LOS was reduced for all patient profiles, but the relative shift in LOS was most favorable for large burns. The savings from LOS reduction with ASCS, relative to SOC estimates, was most favorable for DPT burns as well as for burns with TBSA of 40% or more, which led to greater reductions in LOS and associated inpatient costs for these patients. Notably, for FT/mixed depth burns of 40% TBSA, the projected reduction in LOS was almost 28 days (SOC, 59.4 days; ASCS, 31.3 days). Further, large relative LOS reductions were seen across all TBSA ranges for DPT, with ASCS-reductions in LOS increasing along with increases in TBSA percentages. Savings due to ASCS were higher in DPT burns relative to FT/mixed-depth burns with 10% (24.6% vs 1.0%), 20% (25.5% vs 3.7%), 30% (28.4% vs 4.9%) TBSA due to fewer autograft procedures and LOS days. However, savings due to ASCS were slightly lower in DPT burns with 40% TBSA (40.5%) compared to FT/mixed-depth burns (42.9%) mainly due to higher incremental difference in LOS and graft surgeries in FT burns. Across all patient profiles, the use of ASCS translates to over 20% reduction in rehabilitation costs (ranging from $1,375 in 10% TBSA to $3,302 in 40% TBSA FT burns; and ranging from $,1,443 in 10% TBSA to $2,727 in 40% TBSA DPT burns), due to a reduced proportion of patients requiring surgical procedures for contracture release and reduced number of days as inpatients with physical therapy and occupational therapy visits. CEM results are reported in Table 4.

Table 4

Burn depth	TBSA	Results measure	SOC	ASCS	Difference $/days (%)
Full-thickness/ mixed-depth thickness	10%	Total Costs	$203,043	$200,913	-$2,130 (-1.0%)
		Total LOS	21.2	20.8	-0.42 (-2.0%)
		No. Grafting Surgeries	1.2	1.0	-0.2 (-16.6%)
	20%	Total Costs	$341,571	$328,990	-$12,581 (-3.7%)
		Total LOS	32.4	31.8	-0.65 (-2.0%)
		No. Grafting Surgeries	2.2	1.0	-1.2 (-53.9%)
	30%	Total Costs	$534,617	$508,566	-$26,051 (-4.9%)
		Total LOS	45.0	44.1	-0.9 (-2.0%)
		No. Grafting Surgeries	2.6	1.0	-1.6 (-61.4%)
	40%	Total Costs	$726,795	$415,144	-$311,652 (-42.9%)
		Total LOS	59.4	31.3	-28.17 (-47.4%)
		No. Grafting Surgeries	3.8	1.0	-2.8 (-73.8%)
Deep-partial thickness	10%	Total Costs	$154,518	$116,486	-$38,032 (-24.6%)
		Total LOS	15.6	10.9	-4.69 (-30.0%)
		No. Grafting Surgeries	1.1	1.0	-0.1 (-12.1%)
	20%	Total Costs	$234,740	$174,985	-$59,755 (-25.5%)
		Total LOS	21.2	14.9	-6.36 (-30.0%)
		No. Grafting Surgeries	1.8	1.0	-0.8 (-45.1%)
	30%	Total Costs	$354,584	$253,792	-$100,792 (-28.4%)
		Total LOS	28.1	19.7	-8.44 (-30.0%)
		No. Grafting Surgeries	2.4	1.0	-1.4 (-58.7%)
	40%	Total Costs	$471,773	$280,859	-$190,914 (-40.5%)
		Total LOS	37.0	19.5	-17.55 (-47.4%)
		No. Grafting Surgeries	3.0	1.0	-2.0 (-66.7%)

Note that only differential grafting surgeries are shown in this Table 4, as treatment phases preceding definitive closure were assumed non-differential. (Please refer to Table 1 in BEACON publication by Kowal S et al., for information on number of debridement and excision procedures.

The overall findings were similar to the Kowal S et al publication with slightly lower cost-savings using the latest real-world survey data due to the overall reduction in number of SOC autograft procedures compared to 2011. Savings due to ASCS across burn depths and TBSA ranges are shown in Figure 4.

Figure 4

Costs by category (341 patients)	Standard of care	ASCS integrated into standard of care	Difference $ (%)
Wound assessment	$843,529	$843,529	$0 (0.0%)
Debridement/Excision	$5,655,361	$5,655,361	$0 (0.0%)
Temporary coverage	$0	$0	$0 (0.0%)
Definitive closure	$12,116,503	$9,336,092	-$2,790,411 (-23.0%)
Rehabilitation	$1,634,459	$1,267,647	-$366,812 (-22.4%)
LOS	$68,849,502	$56,996,179	-$11,853,324 (-17.2%)
Othera	$1,836,542	$1,836,542	$0 (0.0%)
Total costs	$90,935,896	$75,096,331	-$15,839,565 (-17.4%)
Average cost per patient (FT and DPT burns only)	$456,964	$377,368	$79,596 (-17.4%)

^aOtherincludes: costs for anesthesia and escharotomy

The previously developed BEACON model evaluated the cost-effectiveness and burn center budget-impact of the use of ASCS compared to conventional STSG for the management of inpatient burns using NBR data from 2002-2011 and cost data from 2017. Although the NBR is a large repository of useful data from most US burn centers, one of its limitations includes a time delay with respect to data analysis which may defer insights on new interventions and constrain the utility of the NBR to burn centers for benchmarking performance. Therefore, this study was conducted to re-assess the potential economic impact of ASCS given the new trends in burn care treatment at individual burn centers via a survey administered to 10% sample of U.S. burn centers and to provide real-world data updates to supplement the NBR by adding important granularity and transparency on detailed patterns for patient outcomes. Using the 2019 burn center survey data, we provide updated values relative to burn care practices for estimating of the value of new interventions relative to SOC given current trends in treatment patterns and patient demographics. Comparison of key clinical, cost and resource utilization inputs relative to the NBR demonstrate a significant increase in the proportion of severe burns treated in an inpatient setting compared to 2011. Results suggest an overall increase in costs and a decreasing trend in the resource use since 2017 and higher costs also create an opportunity for greater savings as a benefit of adopting a cost-saving intervention such as ASCS.

The impact of ASCS use on patient LOS, number and duration of definitive closure procedures, inpatient resource utilization, and the estimated cost impact to a burn center for treatment of severe burns in the U.S. were shown to be favorable cost savings across all patient profiles (by burn depth and TBSA) compared to SOC. The major cost driver is the reduced number surgical procedures due to ASCS use which is due to the reduced need for donor skin. In both, FT/mixed depth and DPT burns, cost-savings increased notably with burn size due to the overall reduction in the number of operations, dressing time, and associated costs compared to SOC. OWSA results suggests that model results remain robust across expected uncertainties or variations in individual model parameters. Leveraging the individual patient results from the CEM, the BIM considered the mix of patients and burn characteristics expected to present in the U.S. annually. Considering the budget across 341 patients distributed across patient profiles consistent with the US severe (TBSA 10%+) burn population (survivors only), the BIM found that changing current treatment strategy to ASCS would be cost saving to a burn center overall. The findings of this study illustrate how the benefits of ASCS use, which include reduced donor skin site harvesting and thus a reduced number of grafting procedures and a faster healing time can translate into economic savings to the burn center 15, 16, 17 . The overall study findings corroborate the original BEACON model which also reported cost savings due to ASCS in comparison to SOC using NBR v8.0 data 5. Currently, there are no other studies available which have conducted an economic evaluation of novel interventions used for definitive closure in inpatient burn care treatment.

This study provides a more realistic and up-to-date economic value assessment of ASCS using current real-world data in the treatment of burn care as inpatient treatment patterns for burns can vary widely in the U.S. It also confirms the opportunity to use the BEACON model to assess any future novel interventions as the treatment of burns varies widely at the burn center level or even by surgeon. It highlights the significance of obtaining current patient characteristics, burn features and surgeon practices as each impacts important steps in burn wound management, ranging from the size of wound excised, amount of donor-skin used, number of autograft surgeries, timing of excision and autograft, type of wound coverage, facility cost structure, daily cost per bed, cost per hour of OR time, as well as timing for patient discharge and outpatient follow-up. In addition, the study also helps to address challenges in understanding the likely impact of a new treatment alternative in terms of costs, provider practices and patient outcomes. This analysis also provides an example of how real-world data coupled with NBR data facilitates a more effective evaluation of new and existing technologies and methods in the burn care pathway in order to improve our understanding of the real-world effectiveness of treatment options in burn care. These findings support the ABA’s goal of improving the quality, outcomes, patient care, effectiveness and cost of burn care through the collection and exchange of information.

As with any economic model, this study is subject to limitations that should be considered when interpreting results. First, costs and resource use were derived from a survey of burn care surgeons, which represent average costs as reported by the burn centers. Second, several assumptions were made to develop a transparent economic model, BEACON (such as individual unit costs and temporary coverage interventions were not considered in detail, and the model also assumes correct diagnosis when determining pathways for a diagnosed burn; please see Kowal S et al publication for detailed assumptions). Where data were unavailable from burn centers, default values from original BEACON model were used. While the above limitations exist, best-practice modeling methods were considered, and key assumptions were validated by burn surgeons to ensure that the analytic conclusions are methodologically sound and have practical application for the burn community.

This survey research to obtain the latest real-world data for input into the BEACON model re-evaluates the impact of ASCS on burn care outcomes and costs for severe burns in the US. Inpatient burn management for individual patient profiles and for burn centers is estimated. Given the changes in current standard of care practice patterns and the distribution of patient characteristics seen nationally, BEACON demonstrates the impact of ASCS use in reducing costs associated with the current treatment of severe burns (10%+ TBSA), particularly in large burns and in burns of indeterminate depth. The cost reductions are due to decreasing LOS, reducing the number of procedures required to close the burn wound, decreasing the donor site size and associated donor site wound care, and reducing the number of downstream contracture procedures.

Acknowledgements:

The authors would like to thank the following burn centers for their contributions to this study:

Arizona Burn Center at Valleywise Health Medical Center, Phoenix AZ

Connecticut Burn Center at Bridgeport Hospital, Bridgeport CT

Lehigh Valley Health Network Regional Burn Center, Allentown PA

Maine Medical Center, Portland ME

MedStar Washington Hospital Center, Washington DC

MetroHealth Burn Care Center, Cleveland OH

N.C. Jaycee Burn Center, Chapel Hill NC

Richard M. Fairbanks Burn Center at Eskenazi Health, Indianapolis IN

UMC Timothy J.Harnar Regional Burn Center, Lubbock TX

UMCNO Burn Center, New Orleans LA

University of California San Francisco Fresno, Fresno CA

University of Missouri Health Care, Columbia MO

University of Tennessee Health Science Center: Firefighters Regional Burn Center, Memphis TN

Wake Forest Baptist Burn Center, Winston-Salem NC

This study was funded by Avita Medical, Valencia, CA.

Conflict of Interest:

This study was sponsored by Avita Medical, Valencia, CA. IQVIA received funding from Avita Medical assist with the survey development, conduct study analyses, and to prepare the manuscript. C Ferrufino, S Kowal and P Vadagam are employees of IQVIA, Inc, which provides consulting and other research services to biopharmaceutical companies.