OBJECTIVES : Medication-overuse headache (MOH), the worsening of a pre-existing headache disorder from frequent use of medications to treat primary headache disorders, can be disabling and costly. Characteristics and healthcare costs in patients with MOH + migraine vs migraine only were compared to study the additional burden of MOH vs migraine alone.

METHODS : Patients diagnosed with migraine with or without (MOH identified from ICD-10 code G44.40 [drug-induced headache]) between 1/1/2019 and 12/31/2019 were identified using the IBM MarketScan Commercial Research Database. Demographics, comorbidities, hospitalization claims, and costs were analyzed. Hospitalization costs were based only on inpatient claims. Annual healthcare costs included inpatient, outpatient, and drug costs, and were adjusted for age, sex, healthcare plan type, and Charlson Comorbidity Index (CCI) using gamma distribution and log link.

RESULTS : Data from 524,417 eligible patients were examined (520,794 migraine only; 3623 MOH + migraine). The groups were similar in age (mean, 40–41 years), sex (women, 80%–84%), and healthcare plan type (employer, 76%–79%). There were no meaningful between-group differences in individual comorbidities, but the mean (SD) CCI was slightly higher in patients with MOH + migraine vs migraine only (0.056 [0.30]) vs 0.050 [0.30]). Hospitalizations were more frequent in the MOH + migraine group vs migraine only (8.5% vs 6.3%). Hospitalization costs in those hospitalized were similar in both groups ($34,957–$36,464). Mean total unadjusted annual costs were higher for MOH + migraine vs migraine only ($18,471 vs $11,757). These cost differences were statistically significant before and after covariate adjustments (P<0.0001).

CONCLUSIONS : This study found that MOH was rarely coded in people with migraine (0.69%), suggesting it is under-coded. Patients with MOH + migraine had a greater likelihood of hospitalization and 57% higher annual healthcare costs vs patients with migraine only. Further studies examining the diagnosis and coding of MOH are warranted.