In patients with migraine, effective preventive treatments that reduce the number of monthly migraine days (MMDs) may decrease the need for acute medication (AM) and loss of work productivity, according to new research published in PharmacoEconomics.
Migraine is linked to high direct and indirect health care costs, which entail lost productivity. Productivity loss includes absenteeism or presenteeism, where the patient works with decreased productivity. Indirect costs are thought to account for 50%-70% of the total costs associated with migraines.
“Accurate quantification of AM costs and productivity losses is essential when assessing the economic impact of migraine and cost-effectiveness of migraine prevention. Indirect costs are substantial and have been considered in previous studies of the cost burden of migraine,” wrote the authors, led by Joshua K. Porter, Economic Modeling Center of Excellence, Amgen (Europe) GmbH, Rotkreuz, Switzerland.
In this study, Porter et al. pooled results from three clinical trials of erenumab to determine how MMD differences during the double-blind period in the clinical trials affected the level of AM use and workplace productivity losses in patients.
Erenumab is a fully human monoclonal antibody that blocks the calcitonin gene-related peptide receptor complex, and is FDA-approved for migraine prevention in adults. This biologic has been shown to significantly decrease MMD frequency in patients with episodic migraine (EM) and chronic migraine (CM) vs placebo, reducing treatment costs and disability in some patients.
The three erenumab studies included in this analysis were the phase 3 STRIVE (EM; n=955) and ARISE studies (EM; n=577), and a phase 2 study (CM; n=667). Aside from MMD eligibility criteria, patient characteristics were similar, with most patients being white and female.
Those in the experimental arms of the study received either 70 mg or 140 mg of erenumab, whereas the control groups received placebo. In the STRIVE and ARISE studies, data were available for as many as 24 weeks, and in the phase 2 study, for 12 weeks.
The team calculated the number of days monthly in which patients used AM as a function of MMD. They assessed productivity losses based on patient responses to the Migraine Disability Assessment (MIDAS) questionnaire. Using zero-inflated Poisson regression models, they predicted AM use and productivity losses per MMD.
“The regression predictions show that as MMD rises, the expected AM use and productivity loss also increases, but the relationship is non-linear,” wrote the authors. “By lowering the MMD of patients, migraine preventives may reduce lost productive time and the requirement for AM.”
The team suggested that, because these relationships were nonlinear and the impact of each additional migraine day was not constant, mean MMD alone may misrepresent economic outcomes. In assessing migraine patient outcomes, the distribution of patients by MMD should be accounted for.
The investigators conceded that their study had limitations. For instance, the MIDAS questionnaire failed to capture proportion of time lost secondary to migraine, as well as work type.
“This analysis shows how lowering MMD via successful prevention can result in lower AM use and productivity losses, and provides a framework for translating clinical endpoints in migraine to potential economic savings,” concluded the authors.
This study was funded by Amgen.