TABLE 1.

Population and cost input parameters

Parameter	Value	Source	Notes
Adult population size (18+ y)	United States: 256 943 733 United Kingdom: 52 673 433 France: 52 641 954	US Census Bureau 18 , 19 UK Office for National Statistics 20 , 21 French National Institute of Statistics and Economic Studies 22	Most recent available data were used: United States: population estimates from December 9, 2020, age breakdown from July 1, 2019 United Kingdom: mid‐2019 France: January 2020
Annual incidence of TMA	6.5 per million	Calculation based on Bendapudi et al, 23 Schönermarck et al, 24 Veyradier et al 13	Same incidence used across study countries
Breakdown of individuals with TMA by diagnosis	23.0% TTP (1.5/m) 13.4% aHUS (0.9/m) 2.3% STEC‐HUS (0.1/m) 61.4% Other (4/m)	Calculation based on Bendapudi et al 23 and Schönermarck et al 24	Same breakdown of TMA used across study countries
Cost of one TPE treatment	United States: $5103.70 United Kingdom: £1822.50 France: €3032.05	United States: Average of figures from Goshua et al, 25 Connell et al 4 and Kim et al 3 United Kingdom: NHS reference costs 2019 (average of costs for the procedure performed as nonelective short and elective or long stays) 26 plus cost for Octaplas 27 (14 units estimated 7 ) France: Public hospital tariff for plasma exchange from ATIH (tariff for GHS9615 GHM28Z16Z) 28 plus costs for fresh frozen plasma (F. Provôt, personal communication)	Older cost estimates inflated to 2019 values using medical care inflation rates
Cost per HemosIL AcuStar ADAMTS‐13 Activity test	United States: $500 United Kingdom: £365.69 France: €412.98	Instrumentation Laboratory, personal communication	Average cost provided in $ and converted to £ and € using xe.com
Cost per standard ADAMTS‐13 activity test	United States: $312.62 United Kingdom: £100 France: €89	United States: Average of figures from Connell et al, 4 Kim et al, 12 Kim et al 3 United Kingdom: University College London Hospitals (Health Services Laboratories) 29 France: Eurofins Biomnis 30	Older cost estimates inflated to 2019 values using medical care inflation rates

Abbreviations: aHUS, atypical (complement‐mediated) hemolytic uremic syndrome; ATIH, Agence Technique de l’Information sur l’Hospitalisation; NHS, National Health Service; STEC‐HUS, Shiga toxin–producing Escherichia coli–associated hemolytic uremic syndrome; TMA, thrombotic microangiopathy; TPE, therapeutic plasma exchange; TTP, thrombotic thrombocytopenic purpura.