Table 3 Some sources for differences in economic evaluations (models).

Topic	Differences
Outcome measure	Disease‐specific (eg, proportion reaching ACR20)
	Generic (eg, QALY)
Underlying data	Primary data
	Summary data from the literature
Perspective	Society or health insurance
Definition of sample	Specific clinical trial population
	General sample from clinical practice
Costs	Tariffs versus opportunity costs
	Valuation method for indirect costs
Time horizon	Short (within trial)
	Medium (5–10 years)
	Lifetime
Assumptions	Extrapolation beyond the clinical trial
	Missing information

QALY, quality‐adjusted life years.