OnabotulinumtoxinA (BTX) has become a mainstream treatment for chronic migraine (CM). Patients often have varied expectations for treatment success but little is known about how these initial impressions influence continuation of therapy.
To record expectations of benefit and procedural discomfort (PD) from initial BTX treatment and to investigate their association with treatment success, defined as continuation of treatment for >3 sessions within a 2-year period.
A retrospective chart review of CM patients receiving initial treatment with BTX was performed. Patients were questioned about their expectations of benefit and PD as rated on a 0-10 scale. Responses were then compared with continuation of therapy beyond 3 sessions to identify the presence of significant association.
Responses from patients (N = 297) were analyzed. About 173 subjects continued with BTX therapy for more than 3 sessions (173/297, 58.3%). Unadjusted odds ratios (OR) for expectation of benefit (EOB) (OR 1.11, 95% CI 0.99-1.24, P = .087) and PD (OR 1.02, 95% CI 0.90-1.16, P = .780) were not significantly predictive of continuing treatment. After considering sex, age, year of treatment, and previous headache preventative trials, only female sex (OR 2.02, 95% CI 1.09-3.74, P = .025) was found to be significantly associated with treatment continuation.
In the usual care setting, PD and EOB are not significantly associated with therapy continuation in patients receiving initial treatment with BTX for the prevention of CM. However, after considering sex, age, year of treatment, and number of previous headache preventives attempted, we found that female patients had twice the likelihood of continuing with BTX therapy compared to male patients with CM.

© 2020 American Headache Society.