Brief intervention for medication-overuse headache in primary care. The BIMOH study: a double-blind pragmatic cluster randomised parallel controlled trial

Background Medication-overuse headache ( MOH) is common in the general population. We investigated effectiveness of brief intervention ( BI) for achieving drug withdrawal in primary care patients with MOH. Methods The study was double-blind, pragmatic and cluster-randomised controlled. A total of 25 486 patients ( age 18-50) from 50 general practitioners ( GPs) were screened for MOH. GPs defined clusters and were randomised to receive BI training ( 23 GPs) or to continue business as usual ( BAU; 27 GPs). The Severity of Dependence Scale was applied as a part of the BI. BI involved feedback about individual risk of MOH and how to reduce overuse. Primary outcome measures were reduction in medication and headache days/month 3 months after the intervention and were assessed by a blinded clinical investigator. Results 42% responded to the postal screening questionnaire, and 2.4% screened positive for MOH. A random selection of up to three patients with MOH from each GP were invited ( 104 patients), 75 patients were randomised and 60 patients included into the study. BI was significantly better than BAU for the primary outcomes ( p<0.001). Headache and medication days were reduced by 7.3 and 7.9 ( 95% CI 3.2 to 11.3 and 3.2 to 12.5) days/month in the BI compared with the BAU group. Chronic headache resolved in 50% of the BI and 6% of the BAU group. Conclusions The BI method provides GPs with a simple and effective instrument that reduces medication-overuse and headache frequency in patients with MOH.