HMO direct costs and health care resource use after implementation of a monthly limit on sumatriptan

The health care casts and resource use of patients with migraine before and after a quantity limit on sumatriptan was introduced in an HMO were compared. A longitudinal, retrospective review of a medical claims database and a pharmacy claims database was conducted for two six-month periods before and after a monthly limit (four tablets or injections) on sumatriptan reimbursement was instituted at an independent practice association-model HMO in February 1997. Patients with at least one medical claim with a diagnosis code for migraine or at least two pharmacy claims for sumatriptan, methysergide, ergotamine, dihydroergotamine, or an ergotamine combination product in 1996 or 1997 were eligible for inclusion. A total of 557 patients were included in the analysis. Migraine-related medical costs and total medical costs increased 1.5% and 24.4%, respectively; neither change was statistically significant. Physician office visits related to migraine increased by 7.8%. The number of hospital admissions for the cohort increased from three to five, but hospital costs decreased by 55.0%. The overall costs of medications for migraine therapy decreased by 4.5%. There was an 8.2% increase in prescriptions for drugs to treat migraine but a 40.0% decrease in their cost, primarily because of decreased sumatriptan use. There was a 33.9% increase in prescriptions for medications that could be used as prophylaxis for migraine and a 49.6% increase in their cost. Implementation of a monthly limit on sumatriptan decreased an HMO's pharmacy costs but did not significantly alter migraine-related direct medical costs and health care resource use of patients with migraine.