Migraine day frequency in migraine prevention: longitudinal modelling approaches

Background Health economic models are critical tools to inform reimbursement agencies on health care interventions. Many clinical trials report outcomes using the frequency of an event over a set period of time, for example, the primary efficacy outcome in most clinical trials of migraine prevention is mean change in the frequency of migraine days (MDs) per 28 days (monthly MDs [MMD]) relative to baseline for active treatment versus placebo. Using these cohort-level endpoints in economic models, accounting for variation among patients is challenging. In this analysis, parametric models of change in MMD for migraine preventives were assessed using data from erenumab clinical studies. Methods MMD observations from the double-blind phases of two studies of erenumab were used: one in episodic migraine (EM) (NCT02456740) and one in chronic migraine (CM) (NCT02066415). For each trial, two longitudinal regression models were fitted: negative binomial and beta binomial. For a thorough comparison we also present the fitting from the standard multilevel Poisson and the zero inflated negative binomial. Results Using the erenumab study data, both the negative binomial and beta-binomial models provided unbiased estimates relative to observed trial data with well-fitting distribution at various time points. Conclusions This proposed methodology, which has not been previously applied in migraine, has shown that these models may be suitable for estimating MMD frequency. Modelling MMD using negative binomial and beta-binomial distributions can be advantageous because these models can capture intra- and inter-patient variability so that trial observations can be modelled parametrically for the purposes of economic evaluation of migraine prevention. Such models have implications for use in a wide range of disease areas when assessing repeated measured utility values

Preventive treatment in migraine and the new US guidelines

E Estemalik, S TepperCleveland Clinic, Neurological Center for Pain, Cleveland, Ohio, USAAbstract: Migraine headaches are among the most common headache disorders seen in various practices. The prevalence of migraine headaches is 18% in women and 6% in men. While millions of Americans suffer from migraine headaches, roughly 3%–13% of identified migraine patients are on preventive therapy, while an estimated 38% actually need a preventive agent. The challenge among physicians is not only when to start a daily preventive agent but which preventive agent to choose. Circumstances warranting prevention have been described in the past, and in 2012, a new set of guidelines with an evidence review on preventive medications was published. A second set of guidelines provided evidence on nonsteroidal anti-inflammatory drugs, herbs, minerals, and vitamins for prevention of episodic migraine. This article describes the updated US guidelines for the prevention of migraines and also outlines the major studies from which these guidelines were derived.Keywords: US guidelines, Canadian guidelines, classification, preventive medicatio