Thirty four trials (n=3,167) were included in the review. In terms of study quality, seven trials were considered moderately biased and 27 trials were considered highly biased. The main reasons for bias within trials were lack of allocation concealment, no details on randomisation method and no details on blinding. Assessment of funnel plots indicated asymmetry and a high risk of publication bias.
Short-term effects of traditional Chinese medicine versus methylphenidate (28 trials, n=2,896 participants):
Overall, traditional Chinese medicine significantly improved outcomes compared to methylphenidate (RR 1.04, 95% CI 1.00 to 1.07, I2=0%).
When outcome measures were formed into subgroups, only criteria of diagnosis and therapeutic effect of internal disease and syndromes showed a benefit of traditional Chinese medicine versus methylphenidate (RR 1.09, 95% CI 1.02 to 1.16, I2=14%).
Only two of the 14 trials that used Connor's Hyperactivity Index (I2>75%, hence narrative synthesis) found an advantage of traditional Chinese medicine over methylphenidate; all other trials found no significant difference.
Short-term effects of traditional Chinese medicine in combination with methylphenidate versus methylphenidate (seven trials, n=598 participants):
Overall, traditional Chinese medicine with methylphenidate had significantly improved outcomes compared to methylphenidate alone (RR 1.22, 95% CI 1.12 to 1.32, I2=0%).
When outcome measures were formed into subgroups, all subgroups were statistically significant: new criteria of disease diagnosis and treatment at home and abroad (RR 1.16, 95% CI 1.02 to 1.30, I2=0%; three trials); criteria of diagnosis and therapeutic effect of internal disease and syndromes in traditional Chinese medicine (RR 1.22, 95% CI 1.09 to 1.37, I2=0%; three trials); and outcome measures not clear (RR 1.57, 95% CI 1.14 to 2.18, I2 not applicable as based on one trial only).
All three trials that assessed Connor's Hyperactivity Index found a significant advantage of traditional Chinese medicine in combination with methylphenidate compared with methylphenidate alone.
Long-term effects:
Five trials of traditional Chinese medicine versus methylphenidate indicated that traditional Chinese medicine was superior to methylphenidate (follow-up ranged from three months to two years).
Two trials of traditional Chinese medicine combined with methylphenidate versus methylphenidate indicated that traditional Chinese medicine in combination with methylphenidate was superior to methylphenidate alone (follow-up ranged from 12 weeks to six months).