Table 1.

Basic characteristics of included studies.

Author(s)	Year	Blinding	Intervention 1				Intervention 2				Outcomes
			Treatment	Mean age	Male	Size	Treatment	Mean age	Male	Size	Response rate	Pain change
Ghahreman et al.20	2010	1	Corticosteroid	49	60.7%	28	Control	44	51.4%	37	✓	✓
		–	Corticosteroid	49	53.6%	30	Control	46	70.0%	28	✓	✓
Kuijper et al.24	2009	0	Collar	47.0	69.1%	69	Physiotherapy	46.7	69.4%	70		✓
			Control	47.7	66.7%	66
Ozturk et al.27	2006	–	Traction	40.2	58.3%	24	Physiotherapy	52.7	36.4%	22	✓	✓
Osterman et al.26	2006	–	Surgery	37	53.6%	28	Control	38	67.9%	28		✓
Kanayama et al.22	2005	–	Serotonin	31.6	45.0%	20	NSAID	33.9	55.0%	20		✓
Vad et al.32	2002	0	Corticosteroid	41.3	–	25	Control	42.1	–	23		✓
Shakoor et al.29	2002	–	Traction	46.66	55.8%	100	NSAID	47.66	55.8%	99		✓
Karppinen et al.23	2001	2	Corticosteroid	43.8	64.0%	79	Control	43.7	58.0%	79		✓
Hofstee et al.21	2002	–	Physiotherapy	38.0	54.2%	80	Control	41.9	62.7%	83	✓	✓
Liu and Zhang25	2000	–	Physiotherapy	–	72.6%	62	Traction	–	34.0%	50	✓	✓
Burton et al.18	2000	1	Physiotherapy	41.9	47.5%	20	Chemonucleolysis	41.9	47.5%	20		✓
Persson et al.28	1997	–	Surgery	45	59.0%	27	Physiotherapy	48	41.0%	27		✓
			Collar	49	63.0%	27
Dilke et al.19	1973	2	Corticosteroid	38.7	53.0%	35	Control	42.3	58.0%	36	✓
Snoek et al.31	1977	2	Control	46.5	54.2%	27	Corticosteroid	43.8	48.1%	24	✓
Brewerton17	1966	–	Traction	20–80	41.2%	114	Collar	–	–	120	✓
Shanthanna et al.30	2014	3	PRF	62	62.5%	16	Control	57	53.3%	14	✓

NSAID: non-steroidal anti-inflammatory drugs; PRF: pulsed radiofrequency.