Table 4.

Variables ranked by order of importance for clustering.

Variable	p-value
Doctor in charge of the follow-up	3.74e-43
Maximal number of days of medication intake	1.55e-37
Type of diagnosis	2.28e-36
Date of the last consultation	9.44e-35
Impact of headache on everyday life	2.68e-26
Medication overuse	2.91e-26
Headaches' frequency	3.56e-21
Socio-professional category	1.14e-16
NSAIDs' consumption	3.38e-15
Triptans' consumption	1.84e-14
Self-medication	4.91e-12
Neurological comorbidity	4.29e-11
Region	2.72e-10
Opioids' consumption	1.03e-9
Acetaminophen's consumption	1.93e-9
Regular exercise	2.51e-9
Alternative medicines	6.5e-8
Drinking status	1.39e-7
Gender	7.37e-7
Number of intakes	0.0000213
Respiratory comorbidity	0.0026
Coffee intake	0.00313