Table 2.

Cost inputs

	Base case value	Sensitivity low	Sensitivity high	Sources
Drug acquisition costa
Cost per unit (2022 USD)
FMBL	$9000	$6750	$11,250	Redbook [18]
SOC	$0	N/A	N/A	Assumption
Subsequent antibiotic useb
Vancomycin	$26.85	$20.14	$33.56	Redbook [19]
Fidaxomicin	$194.14	$145.61	$242.68	Redbook [19]
Strength per unit
FMBL	150 ml	N/A	N/A	PUNCH CD3 [6]
SOC	N/A	N/A	N/A
Subsequent antibiotic useb
Vancomycin	125 mg	N/A	N/A	Redbook [19]
Fidaxomicin	200 mg	N/A	N/A	Redbook [19]
Total units required per regimen
FMBL	1	N/A	N/A	PUNCH CD3 [6]
SOC	N/A	N/A	N/A	Assumption
Subsequent antibiotic useb
Vancomycin taper-pulse	83	N/A	N/A	IDSA 2021 guidelines [2]
Fidaxomicin	20	N/A	N/A	IDSA 2021 guidelines [2]
Treatment distribution among subsequent antibiotic users
Vancomycin	93.1%	N/A	N/A	PUNCH CD3 [6]
Fidaxomicin	6.9%	N/A	N/A	PUNCH CD3 [6]
Total drug acquisition cost per regimen (2022 USD)
FMBL	$9000	$6750	$11,250	Calculation
SOC	$0	N/A	N/A
Subsequent antibiotic useb	$2342.36	N/A	N/A
Drug administration cost
Unit cost per admin or pharmacy dispensing (2022 USD)
FMBL	$113.85	$85.39	$142.31	CMS physician fee schedule [20]
SOC	$0	N/A	N/A	Assumption
rCDI-related medical cost
Unit cost (2022 USD)
Hospitalization per day	$2039.06	$1529.30	$2548.83	HCUPnet [21]
ICU per day	$5232.00	$3924.00	$6540.00	Halpern 2016 [22]
ED per visit	$1003.73	$752.80	$1254.66	Nelson 2021 [23]
Post-acute care per day	$562.12	$421.59	$702.65	Nelson 2021 [23]
Outpatient per visit	$208.67	$156.50	$260.84	Optum360 National Fee Analyzer [24]
Stool test	$58.35	$43.76	$72.94	Rodrigues 2017 [25]
Resource use per year
Hospitalization stays	1.60	1.20	2.00	Rodrigues 2017 [25]
LOS per hospitalization	15.80 days	N/A	N/A	Rodrigues 2017 [25]
ICU days	0.18	0.14	0.23	Rodrigues 2017 [25]
ED visits	0.12	0.09	0.15	Rodrigues 2017 [25]
Post-acute care days	21.08	15.81	26.36	Rodrigues 2017 [25]; Nelson 2021 [23]
Outpatient visits	2.20	1.65	2.75	Rodrigues 2017 [25]
Stool tests	4.40	3.30	5.50	Rodrigues 2017 [25]
Total rCDI-related medical costs (excluding colectomy-related cost and terminal care cost)
Medical cost per year	$64,810.39	N/A	N/A	Calculation
Medical cost per 8 weeksc	$9970.83	N/A	N/A	Calculation
Colectomy-related costs
Cost per event (2022 USD)
Colectomy	$54,421.37	$40,816.03	$68,026.71	Rodrigues 2017 [25]
Ileostomy reversal	$46,297.54	$34,726.16	$57,871.93	Wilson 2013 [26]
Terminal care costs
One-time cost (2022 USD)
Terminal care	$53,332.75	39,999.56	66,665.94	Byhoff 2017 [27]

Cost parameters were varied by ± 25% in the sensitivity analysis

CMS Centers for Medicare & Medicaid Services, ED emergency department, FMBL fecal microbiota, live-jslm, HCUP Healthcare Cost and Utilization Project, ICU intensive care unit, LOS length of stay, N/A not applicable, rCDI recurrent C. difficile infection, SOC standard of care, USD United States dollar

^aThe dosing schedules for subsequent antibiotics were based on IDSA 2021 guidelines (vancomycin taper-pulse over 6 weeks, fidaxomicin 10 days)

^bDrug costs of subsequent antibiotics were estimated on the basis of the average wholesale acquisition cost of oral forms (tablet or solution) of vancomycin and fidaxomicin taken from Redbook

^cThe total annual rCDI-related medical costs were calculated as the sum of the resource use per year multiplied by the unit cost across care settings and then were converted to cost per 8-week cycle (8 out of 52 weeks of the annual cost) and applied to patients that stayed in the rCDI health state per model cycle