Predicting prognostic factors in a randomized controlled trial of acupuncture versus topiramate treatment in patients with chronic migraine.

Background: This study aimed to identify predictive factors of outcome in patients with chronic migraine (CM) treated with acupuncture or topiramate in a randomized controlled trial.

Methods: Sixty-six consecutive CM patients were treated with either acupuncture (n=33) or topiramate (n=33) in a 12-week period. Data on potential predictive factors were collected at baseline, and secondary data analysis was performed to identify factors associated with treatment response. Treatment prognosis was defined as the change in mean number of moderate/severe headache days per 4 weeks from the 4-week baseline periods.

Results: The median change in mean number of moderate/severe headache days per 4 weeks for patients with higher baseline headache days (>20 d) was significantly greater than that for lower baseline headache days (≤ 20 d) (median ± interquartile range: -12 ± 2 vs. -10 ± 1 d, P=0.01) in acupuncture group. There was a greater change in mean number of moderate/severe headache days per 4 weeks for high moderate/severe headache days (>20 d) than in low days (≤ 20 d) (-12 ± 1 vs. -10 ± 2 d, P=0.015) in acupuncture group. patients with throbbing symptoms had better prognosis with acupuncture than those without throbbing (-12 ± 2 vs. -9.5 ± 2.5 d, P=0.004). Higher score (>5 points) in the general expectations for improvement predicted better response in both treatment groups (>5 vs. ≤ 5 points: -12 ± 2 vs. -9 ± 2 d for acupuncture group; -10 ± 3 vs. -7 ± 4 d for topiramate group; P<0.001).

Conclusions: Some variables can predict outcome in acupuncture or topiramate treatment of CM patients. Identifying predictors of prognosis of both treatments for CM may help improve outcomes in future work.