Table 1.

PICOSTEPS applied in the highly active relapsing MS cost assessment model (CAM) input

PICOSTEPS [16, 21–23]	Definition	Respective sources
P: patients	Disease: highly active relapsing MS	[9–12, 24, 25]
	Feasible MS population in Finland: 280 patients	Sales statistics estimate for dynamic population
	Gender: 72% women	[16]
	Weight: 86.4 kg male, 72.4 kg female	[26]
I: intervention	Cladribine tablets	[10]
C: comparators	Fingolimod and natalizumab, and a treatment mix (80% use fingolimod, 20% use natalizumab)	[11], Finnish clinical practice for natalizumab, sales statistics for the treatment mix
O: outcomes	Expected annual and cumulative drug-associated costs, cost dispersion	Rationale: [27, 28]
S: setting	Modelled specialist care in Finland	[10–12]; clinical practice
T: time	Four years drug acquisition costs at June 2019 values, hospital district tariffs at 2019 values, other costs at year 2018 values, no discounting	Rationale: [27, 28]
E: effects	Drug-associated costs (screening, acquisition, administration, monitoring, adverse events, travelling, productivity)	SmPCs [10–12] or clinical practice; see Tables 2 and 3
P: perspective	Drug-related costs (partially societal)	Logical assumption
S: sensitivity analyses	P: 50% or 90% female	Assumption
	P: average age 36 years	[16]
	P: age–weight distribution	[26]
	I: adherence decreases 10% each year	As above, assumption
	C: adherence decreases 10% each year	Assumption
	S: no screening	Assumption
	T: 3-year results	Assumption
	E: fingolimod use based on clinical practice	Finnish clinical practice (fingolimod)
	E: natalizumab use based on Tysabri SmPC	[12]
	E: natalizumab administration based on Finnish price tariffs	[29, 30]
	E: All cost inputs ±20%	Assumption
	E: fingolimod used after cladribine tablets (sequential approach)	Assumption (risks: [31])
	P: direct costs	[32]
	P: direct costs without travelling costs	[32]
	P: drug costs alone	[32]