Table 2.

Characteristics of the included reviews.

Studies	Country	Trials (subjects)	Treatment intervention	Control intervention	Quality assessment	Results
Li [9]	China	6 (459)	AA	CM	Jadad	AA can reduce the PSQI score and improve the sleep of patients with insomnia.
Yang [10]	China	7 (939)	AA	CM	Cochrane criteria	AA has a certain effect on insomnia and improves patients' sleep quality.
Tan [11]	China	8 (894)	AA	CM; placebo	Cochrane criteria	AA can effectively improve sleep quality, but due to the low evidence quality, cautious attitude should be taken on this conclusion.
Lan [12]	China	15 (1381)	AA	CM; placebo	Cochrane criteria	Statistical analyses of the outcomes reveal a positive effect of AA for insomnia.
Yeung [13]	China	40 (4115)	AA	CM; placebo	Cochrane criteria	Owing to the methodological limitations of the studies and equivocal results, the current evidence does not allow a clear conclusion on the benefits of AA for insomnia.
Lee [14]	Korean	10 (1540)	AA	CM; placebo	Jadad	Because of the paucity and of the poor quality of the data, the evidence for the effectiveness of AA for the symptomatic treatment of insomnia is limited.
Chen [15]	China	6 (673)	AA	CM; placebo	Cochrane criteria	AA appears to be effective in treating insomnia. Further clinical trials with higher design quality, longer duration of treatment, and longer follow-up should be conducted.

AA: auricular acupuncture; CM: conventional medication.