Table 5.

Assumptions adopted when calculating the health effects

Efficacy
Efficacy of medications, migraine	ASA 1 g = 0.39 [30] Sumatriptan 50 mg = 0.35 [22] Amitriptyline 100 mg daily = 0.44 [23]
Efficacy of medications, TTH	ASA 1 g = 0.75 (expert opinion) Paracetamol 1 g = 0.59 [31] Amitriptyline 100 mg daily = 0.3 (expert opinion)
Efficacy of withdrawal, MOH	Efficacy = reverted to migraine 85%*2/3 + reverted to TTH 85%*1/3 + unchanged but off medications 15% (expert opinion)
Uptake
Uptake of medications, migraine	ASA 1 g = 0.635 (expert opinion) Sumatriptan 50 mg = 0.005 (expert opinion) Amitriptyline 100 mg = 0.007 (expert opinion)
Uptake of medications, TTH	Analgesic ASA 1 g = 0.1 (expert opinion) Paracetamol 1 g = 0.456 (expert opinion) Amitriptyline 100 mg = 0 (expert opinion)
Treatment efficacy (weighted by medications uptake)
Efficacy*uptake calculations	One medication = [proportion with effect] * [effect] * [uptake]; Combination of two medications = [(proportion with effect)medication A * (effect)medication A * (uptake)medication A] + [(proportion with effect)medication B * (effect)medication B * (uptake)medication B]
Healthy life years (HLYs)
HLYs untreated = DW * proportion of time with headache (= number/year * duration in years); HLYs treated = HLYs untreated - HLY gained from treatment; HLYs gained = HLYs untreated * efficacy; Total HLYs gained per person = sum of (gains from each treatment * probability of having each treatment) HLYs gained across the population = HLY gained per person affected * prevalence.
HLYs MOH treated = unchanged in 15% + migraine treated HLYs in 2/3*42.5% + TTH treated HLYs in 1/3*42.5%.