Predictors of successful primary care detoxification treatment for medication-overuse headache

Objectives: To investigate predictors for successful treatment outcome after a brief intervention (BI) for medication-overuse headache (MOH). Materials and methods: This study evaluated predictors of successful withdrawal among patients initially participating in a pragmatic cluster-randomized controlled trial with single crossover in Norwegian general practice (the BIMOH study). BI (early or after crossover) was compared to business as usual (BAU) for the treatment of MOH. Patients were followed up 3 months after the BI. Results: In total, 46 patients had the chance to receive the BI (24 early and 22 after crossover) and were included in the predictor analyses. The mean reduction in headache and medication days/month from baseline for the BI was 6.9 (95% CI: 4.8-9.1) and 10.9 (8.1-13.6). The mean percentage reduction in headache and medication days was 30.5% (21.4-39.7) and 50.4% (39.5-61.3). Only five patients started prophylactic medication. Neither age, gender, co-occurrence of migraine, main type of overused drug at baseline nor Severity of Dependence Scale score at baseline predicted successful withdrawal in the prespecified analyses. Headache days/month and medication use at baseline were significant predictors in exploratory analyses with more headache and medication days predicting worse outcome. Conclusions: Brief intervention for MOH is a simple and effective intervention in primary care. As the only identified predictors were frequency of headache and medication use, we conclude that treatment for all MOH patients should be attempted in primary care before referral. A raised awareness of MOH is important, as the condition is highly preventable and treatable.