Network analysis of adolescent non-suicidal self-injury subgroups identified through latent profile analysis

Table 1 Measures of variables in risk factor-resilience networks across all study participants

Measure	Description	Scoring	Total score/subscales	α
PHQ-9 (Martin et al[34], 2006)	Measures the severity of depression	9 items 4-point scale ranging from "never" (1 point) to "very often" (4 points)		0.886
MASHS (Feng et al[35], 2008)	Measure the method and severity of self-harming behavior in an adolescent's lifetime	18-item, the first part: A 4-point scale ranging from (0, 1, 2–4, 5, and more); the second part: A 5-point scale (0 = none to 5 = extremely severe	The frequency of NSSI behavior is categorized into two parts (frequency and severity)	0.84
S-EMBU-C ( Jiang et al[36], 2010)	Assess parenting styles experienced during childhood years	21 items. 4-point scale ranging from “Never” (1 point), “Occasionally” (2 points), “Frequently” (3 points), and “Always” (4 points)	Two parts to three dimensions: Rejection, emotional warmth, and overprotection	0.827
CTQ-SF (Bernstein and Fink[37], 1998)	Measure traumatic childhood experiences	28-item 5-point scale (1 = never, 2 = once, 3 = twice to four times, 4 = five times or more)	PA, EA, SA, PN, and EN	0.871
OBVQ (Solberg and Olweus[38], 2003)	Evaluate traditional school bullying, encompassing physical, verbal, and relation and attitude to bully	14 item 5-point Likert scale (1 = never happened, 2 = altogether once or twice, 3 = 2–3 times per month, 4 = once a week, 5 = several times a week)	Traditional bullying, another to physical bullying, and a third to attitudes towards bullying behaviors	0.72
RSCA (Hu and Gan[39], 2008)	Assess resilience	27-item 5-point scale (1 = never, 2 = once, 3 = twice to four times, 4 = five times or more)	Five components of resilience (goal concentration, emotion regulation, positive perception, FS, and interpersonal help)	0.82
MPAI(Leung[40], 2008)	Assess the levels of mobile phone addiction among the participants, and it has good reliability and validity	17 items 5-point Likert scale (1 = never, 5 = always)	4 subscales: ICCS, FALS, WES, and PLS	0.86

PHQ-9: The Patient Health Questionnaire nine-item depression scale; MASHS: Modified adolescents self-harm survey; S-EMBU-C: The short Chinese Egna Minnen av Barndoms Uppfostra; CTQ-SF: The Childhood Trauma Questionnaire-Short Form; OBVQ: The Chinese version of the Orvis Bullying/Victimization Questionnaire; RSCA: Resilience Scale for Chinese Adolescents; MPAI: The mobile phone addiction index scale amended by Leung; PLS: The productivity loss subscale; WES: The withdrawal and escape subscale; FALS: The feeling anxious and lost subscale; ICCS: The inability to control cravings subscale; FS: Family support; EN: Emotional neglect; PN: Physical neglect; SA: Sexual abuse; EA: Emotional abuse; PA: Physical abuse; NSSI: Non-suicidal self-injury.

Table 2 Overview of influence factors (including means and standard deviations) from subgroup data

No.	Risk factor	Short codes	M (SD)
			X1	X2	X3
1	Paternal warmth	PW	19.73 (4.99)	21.21 (5.03)	20.85 (5.04)
2	Maternal warmth	MW	20.68 (5.05)	20.71 (4.82)	21.89 (4.66)
3	Father reject	FR	8.17 (2.76)	7.54 (2.44)	7.7 (2.49)
4	Mother reject	MR	9.94 (2.28)	9.7 (2.01)	9.73 (2.15)
5	Father overprotective	FO	15.91 (3.8)	15.18 (4.01)	15.39 (3.9)
6	Mother overprotective	MO	16.85 (4.05)	16.16 (4.44)	16.21 (4.18)
7	Emotional abuse	EA	6.78 (2.53)	6.68 (2.53)	6.81 (2.62)
8	Physical abuse	PA	5.71 (1.48)	5.72 (1.6)	5.84 (1.8)
9	Sexual abuse	SA	5.12 (0.6)	5.15 (0.66)	5.14 (0.67)
10	Emotional neglect	EN	10.5 (4.01)	10.4 (4.19)	10.41 (4.23)
11	Physical neglect		6.71 (2.29)	6.62 (2.43)	6.74 (2.47)
12	Bullied	BL	8.56 (2.76)	7.26 (0.67)	8.04 (2.44)
13	Attitudes bullying	AB	17.08 (3.4)	17.45 (3.16)	17.46 (3.29)
14	Bullying	PB	6.5 (1.21)	6.07 (0.53)	6.17 (0.65)
15	Targeted focus	TF	17.95 (4.52)	19.38 (4.28)	18.72 (4.67)
16	Emotional control	EC	19.39 (4.05)	20.47 (4.04)	20.3 (4.02)
17	Positive cognition	PC	14.53 (3.72)	15.32 (3.47)	14.97 (3.73)
18	Interpersonal interactions	II	20.84 (5.92)	22.33 (5.79)	22.25 (5.77)
19	Family support	FS	23.82 (4.56)	23.42 (4.68)	23.3 (4.67)
20	Smartphone addiction - withdrawal	SW	6.9 (3.76)	5.84 (3.01)	6.35 (3.54)
21	Smartphone addiction - out of control	SO	17.23 (7.31)	15.72 (7.25)	15.89 (7.39)
22	Smartphone addiction - avoidance	SV	7.41 (3.59)	6.52 (3.35)	6.92 (3.62)
23	Smartphone addiction - inefficiency	SI	5.42 (2.66)	4.89 (2.44)	5.08 (2.61)

Influence factor names and No. Short codes were applied completely by paper.

Table 3 Fit indices for three models using latent profile analysis (n = 3967)

M	df	χ2	G2	aBIC	AIC	Entropy	LMR	BLRT	Group size for each profile (%)
									1	2	3	4
1	2963	16130	312372	386431	380120.1	-	-	-	3967 (100)
2	2742	12040	290985.2	366874.6	359174.5	0.781	0.043	0.001	1225 (35.7)	2742 (64.3)
3	1121	23910	282288.2	371608.7	353719.4	0.742	0.342	0.001	488 (12.3)	747 (18.8)	2732 (68.9)
4	1292	26059	279126.3	367029.9	350215.5	0.670	0.471	0.001	1067 (26.9)	603 (15.2)	1944 (49)	353 (0.088)

Numbers in bold indicate “best” fit. AIC: Akaike information criterion; BIC: Bayesian information criterion; aBIC: Adjusted Bayesian information criterion; pLMR: P value for LoMendell-Rubin adjusted likelihood ratio test for K vs K-1 profiles; pBLRT: P value for bootstrapped likelihood ratio test.

Table 4 Centrality measures of key risk and resilience factors across non-suicidal self-injury subgroups

Factor	NSSI-ND (strength)	NSSI-D (strength)	NNSSI-ND (strength)
Paternal warmth	0.72	0.68	0.75
Maternal warmth	0.69	0.71	0.74
Family support	0.63	0.60	0.70
Bullying	0.75	0.78	0.65

NSSI-ND: Non-suicidal self-injury-without depression; NSSI-D: Non-suicidal self-injury-with depression; NNSSI-ND: No non-suicidal self-injury-without depression.