Table 1.

Demographic characteristics of the studies included in the meta-analysis.

Study	Country	Study type	Sex		Cases		Average age (years)		BMI
			M	F	RA	FH	RA	FH	RA	FH
Cui et al. (25)	China	RCT	10	38	23	25	51.3 ± 9.8	54.1 ± 10.2	N/A	N/A
Fan et al. (26)	China	RCT	82	45	61	66	49	49.5	23.65 ± 4.1	24.47 ± 3.94
Feng et al. (20)	China	RCT	31	49	40	40	63.45 ± 4.56	64.22 ± 6.19	N/A	N/A
Han et al. (27)	China	RCT	113	121	115	119	54.6 ± 11.3	56.1 ± 11.4	25.7 ± 4.1	24.9 ± 2.9
Hyun et al. (28)	Korea	RCT	17	43	30	30	66.5 ± 8.1	66.8 ± 8.9	24.7 ± 2.6	25.8 ± 3.3
Kim et al. (29)	Korea	RCT	41	37	37	41	65.4 ± 10.4	66.0 ± 8.6	25.9	25.3
Li et al. (30)	China	RCT	7	10	7	10	47.4 ± 12.9	49.9 ± 10.9	24.3 ± 1.8	24.6 ± 2.6
Ringel et al. (31)	Germany	RCT	26	34	30	30	68	67	26	28
Roser et al. (32)	Germany	RCT	N/A	N/A	18	10	N/A	>18	N/A	N/A
Wang et al. (33)	China	RCT	63	19	40	42	42.7 ± 8.0	43.1 ± 9.1	N/A	N/A
Hou et al. (34)	China	RCT	49	13	32	30	43.1 ± 8.91	44.2 ± 9.10	26.15 ± 3.97	25.97 ± 4.02
Wang & Kedong (35)	China	RCT	27	33	28	32	55.7 ± 6.2	56.0 ± 7.4	26.3 ± 3.1	25.9 ± 2.9
Huang et al. (57)	China	RCT	33	27	28	32	54.32 ± 6.54	54.81 ± 7.56	26.22 ± 5.07	25.81 ± 3.42
Xu et al. (37)	China	RCT	25	18	24	19	45.2 ± 9.2	50.6 ± 10.7	N/A	N/A
Wei et al. (38)	China	RCT	17	23	23	17	55.5 ± 10.1	52.0 ± 14.1	N/A	N/A
Zhai et al. (39)	China	RCT	11	20	16	15	16.7 ± 7.0	15.4 ± 4.6	N/A	N/A
Zhang et al. (43)	China	RCT	47	43	44	46	54.82 ± 3.51	55.06 ± 3.57	N/A	N/A
Yang et al. (40)	China	RCT	49	39	45	43	45.27 ± 7.71	47.83 ± 6.82	N/A	N/A
Cao et al. (41)	China	RCT	19	11	15	15	16.08 ± 2.31	16.16 ± 2.26	N/A	N/A
Li et al. (42)	China	RCT	N/A	N/A	12	10	N/A		N/A	N/A

FH, freehand; RA, robot-assisted; RCT, randomized controlled trial.