Fig. 3From: The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regressionMean change in placebo response A) adjusted for patient age, sex, route of administration, Cochrane risk of bias, and year of publication and B) adjusted for study duration, type of efficacy outcome, permission to use other prophylaxis medications along with predictors listed in ‘A’Back to article page