Impact of insurance status on migraine care in the United States: a population-based study.

OBJECTIVE: To determine whether insurance status is associated with differential outpatient treatment of migraine in the United States.
METHODS: We analyzed 11 years of data from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey (1997-2007), which survey patient visits to doctors' offices, hospital outpatient departments, and emergency departments (EDs) in the United States. We used logistic regression to determine whether insurance status was associated with the prescription of standard migraine therapy, defined as 1) a triptan or dihydroergotamine and 2) a prophylactic agent.
RESULTS: We identified 6,814 individual patient visits for migraine, representing 68.6 million visits nationally. After controlling for age, gender, race/ethnicity, geographic location, and year, migraineurs with no insurance or Medicaid were less likely than the privately insured to receive abortive therapy (odds ratio [OR] for failure to receive medication 2.0 [95% confidence interval (CI) 1.3, 3.0] and 1.6 [95% CI 1.1, 2.3]) and prophylactic therapy (OR 2.0 [95% CI 1.3, 2.9] and 1.5 [95% CI 1.0, 2.1]). Adding site of care to the regression model suggested that one mechanism for this discrepancy was the reliance of the uninsured on EDs for migraine care, a site where standard migraine care is often omitted (OR for failure to receive abortive and prophylactic medication in the ED relative to physicians' offices 4.8 [95% CI 3.6, 6.3] and 8.7 [95% CI 6.4, 11.7]).
CONCLUSIONS: The uninsured, and those with Medicaid, receive substandard therapy for migraine, at least in part because they receive more care in emergency departments and less in physicians' offices.