Table 1. Clinical severity according to age and sex in children with HSP.

			Incidence (per 1,000 children with HSP)	HR	95% CIs
Hospitalization
	Total		20.556
	Male		22.511
	Female		18.664	0.856	0.811–0.904
	0–8 yr		26.484
	9–17 yr		11.408	0.455	0.426–0.486
Re-hospitalization
	After 3 months
		Total	3.449
		Male	3.448
		Female	3.450	0.999	0.879–1.135
		0–8 yr	3.644
		9–17 yr	3.124	0.868	0.758–0.993
	After 6 months
		Total	2.867
		Male	2.857
		Female	2.876	1.003	0.869–1.158
		0–8 yr	2.991
		9–17 yr	2.660	0.899	0.773–1.045
	After 12 months
		Total	2.222
		Male	2.197
		Female	2.246	1.022	0.862–1.212
		0–8 yr	2.387
		9–17 yr	1.946	0.822	0.686–0.985
Comorbidity
	Intussusception
		Male	0.643
		Female	0.450	0.733	0.534–1.007
		0–8 yr	0.813
		9–17 yr	0.102	0.129	0.070–0.238
	Abdominal intervention
		Male	0.153
		Female	0.110	0.750	0.394–1.428
		0–8 yr	0.189
		9–17 yr	0.037	0.202	0.072–0.569
	HSP arthritis
		Male	0.433
		Female	0.463	1.103	0.781–1.558
		0–8 yr	0.600
		9–17 yr	0.195	0.328	0.205–0.523
	HSP nephritis
		Male	2.413
		Female	2.043	0.849	0.726–0.993
		0–8 yr	2.413
		9–17 yr	1.916	0.809	0.685–0.955

HSP = Henoch-Schӧnlein purpura, HR = hazard ratio, CI = confidence interval.