Economic burden of transformed migraine: results from the American Migraine Prevalence and Prevention (AMPP) Study.

OBJECTIVE To evaluate the impact of incident transformed migraine on health care resource utilization, medication use, and productivity loss. In addition, the study estimates the total direct and indirect costs associated with transformed migraine. BACKGROUND Emerging evidence indicates that migraine may be a chronic progressive disorder characterized by escalating frequency of headache attacks, often termed transformed migraine. Little is known about the economic impact of transformed migraine. METHODS AMPP is a 5-year, national, longitudinal survey study of headache in the US. The study utilized data from the 2006 follow-up survey based on an initial sample of 14,544 adults identified as having migraine in either the 2004 screening or 2005 baseline survey. A diagnosis of migraine was assigned based on criteria proposed by the International Classification of Headache Disorders, 2nd Edition. Participants completed self-administered, validated questionnaires on headache features, frequency, impairment, resource use, medication use, and productivity loss. Direct and indirect headache-related costs were estimated using unit cost assumptions from the PharMetrics Patient-Centric database, wholesale acquisition costs (Red Book), and wage data from the US Bureau of Labor Statistics. Those who developed transformed migraine were compared with those who did not develop transformed migraine in the 1-2 year interval between screening/baseline and follow-up. RESULTS A total of 7796 (54%) identified migraine cases completed the 2006 follow-up survey. Of those cases, 359 (4.6%) developed transformed migraine. Participants who developed transformed migraine reported significantly more primary care visits, neurologist or headache specialist visits, pain clinic visits, and emergency room visits compared with participants whose migraine remained episodic. Hospital nights and urgent care visits did not reach statistical significance. Transformed migraine participants reported significantly more time missed at work or school because of headaches and more time where work or school productivity was reduced by >50% in the previous 3 months because of headaches. Average per-person annual total costs, including direct and indirect costs, were 4.4-fold greater for those who developed transformed migraine ($7750) compared with those who remained episodic ($1757). CONCLUSION Transformed migraine exacts a significantly higher economic toll on patients and health care systems compared with other forms of migraine. Our findings support the need to prevent migraine progression and to provide appropriate management and treatment of transformed migraine.