Fig. 6From: 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 trialReduction in mean GPE by chiropractic treatment at two selected values for each candidate variables. The estimates are based on a model assuming a linear change of the treatment effect in dependence on the values. Interactions refer to the difference in reduction between the two selected values. Positive interactions indicate a more distinct advantage of chiropractic manipulation in case of the second (larger) value selectedBack to article page