Long-term predictors of remission in patients treated for medication-overuse headache at a specialized headache center: A prospective cohort study.

Objective To evaluate long-term predictors of remission in patients with medication-overuse headache (MOH) by prospective cohort study. Background Knowledge regarding long-term predictors of MOH outcome is limited. Methods Two hundred and forty MOH patients recruited from 2000 to 2005 were included in a one-year follow-up study and then subsequently followed until 31 December 2013. The median follow-up was three years (interquartile range, three years). Predictive values of selected variables were assessed by the Cox proportional hazard regression model. Results At the end of follow-up, 102 (42.5%) patients were in remission. The most important predictors of remission were lower number of headache days per month before the one-year follow-up (HR-hazard ratio = 0.936, 95% confidence interval (CI) 0.884-0.990, p = 0.021) and efficient initial drug withdrawal (HR = 0.136, 95% CI 0.042-0.444, p = 0.001). Refractory MOH was observed in seven (2.9%) and MOH relapse in 131 patients (54.6%). Conclusions Outcome at the one-year follow-up is a reliable predictor of MOH long-term remission.