From: 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 trial
Candidate variable
Weight
Effect
Frequency of headache
0.17
0.26
Length of episode
0.02
0.03
Sport activity
0.13
0.25
Sleep duration
− 0.13
− 0.40
Trauma experience
0.05
History of neck pain
0.21
0.43
Headache in the family
0.19
0.33