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Migraine in Primary Care Advisors

MIPCA Projects

How to evaluate clinical trial evidence

This project produced guidance on how to evaluate clinical evidence as published in original articles and reviews. Large, randomised, double-blind, controlled clinical trials form the gold standard of clinical evidence for evaluating new medications. Meta-analyses and post hoc analyses of existing trials are increasingly used to compare therapies, in part to spare the expense and time required to conduct direct comparator studies. However, these analyses have been criticised methodologically, and should not be used on their own to evaluate therapies.

Controlled clinical trials evaluating triptans in the acute treatment of migraine demonstrate clear superiority of the drugs over placebo, but only small differences are reported in studies comparing individual triptans and triptans with non-triptan medications. In contrast, patients can clearly distinguish between triptans and non-triptans and between different triptans in clinical practice. This incongruence may be due to the relative insensitivity of the standard clinical trial endpoint, relief of headache.

New and more sensitive clinical trial endpoints are required for use in clinical studies that reflect everyday general practice (naturalistic studies). Among the potential endpoints are assessments of patient preference, impact on the patient’s daily life and quality of life. However, novel endpoints may be needed that can summarise the whole migraine experience. One potential new endpoint is the 4-item Migraine Assessment of Current Therapy (Migraine-ACT) questionnaire, which is a reliable and valid measure of acute treatments


Dowson AJ, Kilminster S, Peters M et al. Understanding the evidence: evaluating the efficacy of migraine medications in clinical practice. Headache Care 2005;2:133–43


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