Table 4.

Top ten keywords with centrality and frequency.

Ranking	Frequency	Keyword	Centrality	Ranking	Centrality	Keyword	Frequency
1	452	Acupuncture	0.19	1	0.61	Trial	35
2	236	Migraine	0.24	2	0.60	Pain	144
3	218	Headache	0.06	3	0.53	Low back pain	92
4	144	Pain	0.6	4	0.50	Electroacupuncture	48
5	126	Tension-type headache	0.40	5	0.43	Analgesia	19
6	97	Efficacy	0.19	6	0.40	Tension-type headache	126
7	92	Low back pain	0.53	7	0.40	Quality of life	38
8	91	Double-blind	0.33	8	0.33	Double-blind	91
9	87	Randomized controlled trial	0.07	9	0.32	Amitriptyline	5
10	81	Placebo	0.02	10	0.24	Migraine	236