Fig. 5From: Potential effect modifiers for treatment with chiropractic manipulation versus sham manipulation for recurrent headaches in children aged 7–14 years: development of and results from a secondary analysis of a randomised clinical trialThe mean GPE stratified by treatment group and 16 candidate variables. The candidate variables have been partially categorized to obtain three to five groups of roughly equal size. (red = chiropractic manipulation group; blue = sham manipulation group. GPE is coded with 1 = ’completely recovered’ and 7 = ’a lot worse’Back to article page