Patterns of medical diagnosis and treatment of migraine and probable migraine in a health plan

The objectives of this study were to assess the proportion of subjects with strict migraine (SM, migraine with and without aura), probable migraine (PM), and all migraine (AM, SM and PM pooled together), who receive a medical diagnosis or a specific treatment within a health plan. Eligible participants were 18-55-year participants of a non-profit health maintenance organization (HMO) who had received out-patient, emergency department, or in-patient care from a physician within the past year. We used a validated computer-assisted telephone interview (CATI) survey to identify SM, PM and controls (received out-patient, emergency department, or in-patient care from a physician for any reason within the past year, but did not have SM or PM). Medical and prescription drug claims for the 24-month period were linked to participant files. Among 8579 respondents, we identified 1265 SM sufferers and 1252 PM sufferers, which were compared with 960 randomly selected controls. Just 194 (15.3%) SM, 21 (1.7%) PM, and 215 (8.5%) AM sufferers received an in-patient or out-patient primary migraine claim in the previous 24 months, compared with six (0.5%) controls; 240 (18.9%) SM, 39 (3.1%) PM, 279 (11.1%) AM sufferers, and eight controls (0.6%) received any migraine claim. There were claims for migraine drugs (ICD-9 code for triptans or ergot compounds) for just 140 (11.1%) SM and 34 (2.7%) PM sufferers, and migraine analgesics (butalbital and isomethepthene compounds), for 6.3% SM and 2.2% PM sufferers (0.7% of the controls). Migraine preventives were used for a larger number of SM and PM sufferers (19.6% and 13.1%), but also for controls (10.5%), indicating that they were probably used for other medical reasons. Both SM and PM are underdiagnosed and undertreated within a health plan. Educational strategies should focus on physician education addressing diagnosing the full spectrum of migraine and physician management of migraine with specific migraine therapy in appropriate patients.