TABLE 4.

Prevalence of non-suicidal self-injury among adolescents based on subgroup analyses.

Subgroup	Number of studies, n	Number of adolescents, n	NSSI prevalence, %	95% CI, %	Heterogeneity test		Subgroup differences
					I2/%	p	OR	95% CI	Z	p
Gender
Male	43	107,285	22.0	19.2–25.0	99.268	<0.001	0.839	0.768–0.918	–3.835	<0.001
Female	43	102,473	25.4	22.4–28.6	99.202	<0.001
Living place
Urban areas	10	37,514	26.6	20.6–33.5	99.428	<0.001	1.048	0.923–1.190	0.727	0.467
Rural areas	10	28,404	25.8	20.9–31.4	98.930	<0.001
Smoking history
Yes	3	1,479	24.7	12.4–43.1	93.050	<0.001	2.588	1.470–4.559	3.293	<0.001
No	3	4,072	10.1	3.2–27.6	99.149	<0.001
Drinking history
Yes	3	2,721	24.4	12.2–42.9	96.610	<0.001	3.014	1.487–6.108	3.060	0.002
No	3	2,850	9.3	3.1–24.8	98.677	<0.001
One child
Yes	16	49,014	25.8	22.5–29.3	98.611	<0.001	0.939	0.889–0.991	–2.269	0.023
No	16	86,402	27.0	24.0–30.3	99.077	<0.001
Single-parent family
Yes	4	1,203	30.1	27.6–32.8	1.758	0.383	1.200	1.056–1.363	2.379	0.017
No	4	19,959	23.5	19.0–28.5	97.183	<0.001