Traumatic Brain Injury and Migraine Risk

Both the cohorts were followed up from the index date to the date of migraine onset, withdrawal from the NHI program, or the end of follow-up. For outcome measurement, migraine was defined using the ICD-9-CM diagnostic code 346 and the ICD-10-CM diagnostic code G43. Patients who received a diagnosis of migraine from a neurologist or an otolaryngologist were enrolled into this study. The cumulative incidence of migraine was estimated according to the TBI status using the Kaplan–Meier method, and differences between the cumulative incidence rates were compared using a log-rank test. Moreover, Cox proportional hazards models were used to compute the crude and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for migraine between the TBI and non-TBI groups and between different TBI subgroups. Injury severity scores (ISS) [32 (link),33 (link)] were used to assess the severity of injury and to predict mortality, morbidity, and length of hospital stay. The ISS ranges from 1 to 75. As per the NHI program in Taiwan, ISS ≥ 16 denotes the presence of major trauma and a catastrophic illness. Patients with any defined catastrophic illness can benefit from copayment exemptions.