Table 1.

Baseline characteristics of the studies included in the review

Study	Year	Country	Sample size	SRNS vs. SSNS	Male n, (%)	Age (years) Mean ± SD / median (range)
Bennet et al. [17]	2012	US	29	15 vs. 14	19 (65.5%)	8.75 ± 5.3
Bennet et al. [18]	2017	US	50	20 vs. 30	34 (68%)	9.4 ± 2.6
Bienias et al. [19]	2015	Poland	59	n/a	49 (83%)	13.7 (4–18)
Chehade et al. [20]	2013	Switzerland	44	n/a	n/a	10 (5–13)
Choudhary et al. [21]	2020	India	84	28 vs. 28	54 (60.7%)	8.06 ± 4.3
El-Gamasy et al. [22]	2017	Egypt	120	45 vs. 45	99 (82.5%)	5.4 ± 2.6
Ezzat et al. [23]	2011	Egypt	45	12 vs. 15	28 (62.2%)	8.7 ± 2.9
Gacka et al. [24]	2016	Poland	31	n/a	n/a	9.2 (3–12)
Gheissari et al. [25]	2013	Iran	104	n/a	69 (66.7%)	10.4 ± 3.73
Jwda et al. [26]	2022	Iraq	57	20 vs. 20	n/a	(range 3–13)
Kumar et al. [27]	2023	India	45	15 vs. 15	28 (62.2%)	(range 1–12)
Murugesan et al. [28]	2023	India	70	3 vs.32	(58.5%)	5.3 ± 3.2
Nickavar et al. [29]	2015	Iran	52	27 vs. 25	34 (65.4%)	(range 1–16)
Ochocinska et al. [30]	2018	Poland	102	14 vs. 29	53 (52%)	9 ± 5
Pradeepchandran et al. [31]	2022	India	79	7 vs. 72	44 (55.7%)	7.18 ± 2.86
Wasilewska et al. [32]	2010	Poland	37	n/a	24 (74%)	9.88 ± 5.73