An economic evaluation of rizatriptan in the treatment of migraine.

BACKGROUND: Migraine is a common, chronic, neurovascular disorder, generally characterised by attacks of severe headache and autonomic nervous system dysfunction. Triptans are selective serotonin 5-HT(1B/1D) receptor agonists that represent effective therapeutic options for moderate-to-severe migraine attacks but with higher acquisition costs relative to usual care therapies.

OBJECTIVE: The objective of this study was to examine the cost effectiveness of rizatriptan treatment compared with 'Usual Care' or other triptans available in Canada for patients with moderate-to-severe migraine for whom other therapies (e.g. NSAIDs, simple analgesics) are insufficient or contraindicated.

METHODS: A decision-analysis model was created to estimate migraine treatment costs over a 24-hour period in patients with a diagnosis of moderate-to-severe migraine as defined by the International Headache Society criteria. Costs and clinical outcomes were observed over a 24-hour period from therapy initiation. Efficacy measures consisted of 'pain-free response at 2 hours' and 'sustained pain free for 2-24 hours'. Oral rizatriptan 10 mg was compared with other oral triptans (i.e. sumatriptan 50 or 100 mg), naratriptan 2.5 mg and zolmitriptan 2.5 mg, based on a meta-analysis and compared with 'Usual Care' based on a naturalistic study of people who experience migraine and who were similar to the target population. 'Usual Care' was defined as an aggregate of medications prescribed for the Canadian population for the indication of migraine, weighted by the relative frequency of use of prescriptions over a 1-year period. Analyses were conducted from the Ontario (Canada) Ministry of Health and Long-Term Care (MOH<C) perspective and the broader societal perspective. Results are presented as the cost per migraine attack aborted (i.e. pain free at 2 hours), as well as the cost per QALY. Several one-way sensitivity analyses were conducted to test the robustness of the model. All costs are expressed in 2002 $Can.

RESULTS: Cost estimates are similar to previously published Canadian studies. Rizatriptan compared with 'Usual Care' produced an incremental cost per attack aborted of $Can49.82 and a cost per QALY gained of $Can31 845 from the MOH<C perspective. When a societal perspective was considered (which included time loss from paid and unpaid work activities), rizatriptan dominates 'Usual Care': that is, it is cost saving and more effective. All other triptans are also dominated by rizatriptan as they offer higher costs and lower efficacy.

CONCLUSIONS: This study shows that rizatriptan treatment for patients who experience moderate-to-severe migraines may represent a cost-effective strategy for improving care of migraine patients in Canada.