Table s1

Results of subgroup analysis of risk factors and clinical features of septic arthritis in children by age group

Risk factor or clinical feature	Age group	Number of studies	Pooled estimate (95% CI)	I2 (%)
Age younger than 3 years	<3 years	12	1.00 (reference)	0
	≥3 years	12	0.43 (0.32–0.57)	0
Male sex	<3 years	14	1.00 (reference)	0
	≥3 years	14	0.97 (0.81–1.16)	0
Previous joint problems or surgery	<3 years	10	1.00 (reference)	0
	≥3 years	10	0.77 (0.51–1.16)	0
Immunodeficiency	<3 years	9	1.00 (reference)	0
	≥3 years	9	0.69 (0.46–1.04)	0
Recent infection or injury	<3 years	8	1.00 (reference)	0
	≥3 years	8	1.02 (0.72–1.45)	0
Fever	<3 years	22	0.81 (0.74–0.88)	67
	≥3 years	22	0.76 (0.69–0.84)	67
Joint pain	<3 years	18	0.90 (0.84–0.96)	56
	≥3 years	18	0.83 (0.77–0.90)	56
Joint swelling	<3 years	18	0.87 (0.81–0.93)	58
	≥3 years	18	0.82 (0.76–0.88)	58
Hip joint	<3 years	24	0.34 (0.27–0.42)	88
	≥3 years	24	0.29 (0.23–0.36)	88
Ankle joint	<3 years	18	0.10 (0.07–0.13)	80
	≥3 years	18	0.09 (0.06–0.12)	80
S. aureus infection	<3 years	28	0.64 (0.56–0.72)	82
	≥3 years	28	0.59 (0.51–0.68)	82