Table 2.

Risk factor categories.

Risk factor	No. of studies	Heterogeneity		Pooled OR	95% CI	Pooled effect size test
		I² (%)	tau²			Z	P
Adverse Childhood Experiences	15	94·9%	0·286	2·49	1·85–3.34	6·056	0·000
Bullying	7	95·5%	0·237	1·98	1·33–2·95	3·348	0·001
Low Health Literacy	2	95·6%	0.044	2·20	1·63–2·96	5·182	0·000
Female Gender	8	20·3%	0·012	2·89	2·43–3·43	12·132	0·000
Mental Disorders	21	99·2%	0·123	1·89	1·60–2·24	7·519	0·000
Physical Symptoms	5	92·8%	0·640	2·85	1·36–5·97	2·771	0·006
Problem Behaviours	21	91·8%	0·099	2·36	2·00–2·77	10·274	0·000
Overall	80	98·3%	0·154	2·25	2·04–2·48	16·125	0·000