Fig. 4

Migraine class among those with HFEM at baseline at month 3 (A) and month 6 (B) after follow-up

Abbreviations: CM: chronic migraine; HFEM: high-frequency episodic migraine; LFEM: low-frequency episodic migraine; OMPM: oral migraine preventive medication; VLFEM: very low-frequency episodic migraine