Table 1.

Characteristics of studies included in the meta-analysis.

References	Sample size			Age (years)	Place	FCV-19S mean score
	Total	Male	Female			Total	Male	Female
Saravanan et al. (34)	433	278	155	21.00 ± 2.90	United Arab Emirates	16.60 ± 6.30	–	–
Rodríguez-Hidalgo et al. (23)	640	179	461	21.69 ± 4.09	Spain	14.37 ± 5.38	–	–
Nguyen et al. (21)	5,423	2,602	2,821	22.00 ± 2.00	Vietnam	16.70 ± 5.30	16.20 ± 5.60	17.00 ± 4.80
Martínez-Lorca et al. (38)	606	109	497	21.59 ± 3.04	Spain	16.79 ± 6.04	–	–
Konstantinov et al. (35)	466	154	312	19.00 ± 2.70	Kazakhstan	22.10 ± 5.80	–	–
Reznik et al. (22)	228	–	–	–	Russia and Belarus	18.00 ± 4.50	–	–
Zolotov et al. (36)	366	77	289	25.20 ± 3.10	Israel	14.95 ± 4.80	–	–
Perz et al. (42)	237	64	173	30.30 ± 10.20	USA	18.10 ± 7.10	–	–
Yehudai et al. (44)	288	46	242	24.40 ± 5.50	Israel and Russia	22.00 ± 6.30	–	–
Masuyama et al. (13)	629	320	309	–	Japan	18.71 ± 5.65	–	–
Isralowitz et al. (45)	593	173	420	–	Israel, Russia, and Belarus	21.20 ± 6.10	–	–
Hasratian et al. (43)	175	58	117	19.83 ± 1.74	USA	15.33 ± 5.75	–	–
De Pasquale et al. (39)	469	221	248	22.47 ± 2.70	Italy	15.90 ± 6.06	15.02 ± 6.02	16.68 ± 6.00
De Pasquale et al. (40)	194	86	108	21.74 ± 2.39	Italy	15.53 ± 6.01	14.01 ± 5.80	16.75 ± 6.24
Muyor-Rodríguez et al. (41)	517	108	409	21.03 ± 4.32	Spain	18.5 ± 5.88	–	–
Green et al. (37)	608	258	350	24.76 ± 3.52	Pakistan	16.74 ± 6.68	15.10 ± 5.88	17.94 ± 6.98