Table 3. HR for urticaria.

	1:4 age and sex matching		1:2 PSM
	Adjusted HR (95% CI)	P value	Adjusted HR (95% CI)	P value
Mycoplasma pneumonia	1.2(1.0–1.4)	0.0086	1.1(1.0–1.3)	0.1058
Sex
Female	Reference		Reference
Male	0.8(0.8–0.9)	0.0017	0.8(0.7–0.9)	0.0011
Age
<6	Reference		Reference
6–11	1.0(0.9–1.2)	0.5678	1.1(0.8–1.4)	0.6129
12–19	1.0(0.8–1.2)	0.7956	0.9(0.7–1.3)	0.6362
20–39	1.0(0.8–1.3)	0.8758	1.2(0.9–1.6)	0.2436
40–59	0.9(0.6–1.1)	0.2882	1.0(0.7–1.6)	0.8946
> = 60	0.8(0.6–1.1)	0.1206	1.0(0.7–1.5)	0.8964
Urbanization
Urban	0.9(0.8–1.1)	0.4895	1.1(0.8–1.4)	0.6349
Sub-urban	1.0(0.9–1.3)	0.6607	1.3(1.0–1.8)	0.0778
Rural	Reference		Reference
Low income	2.1(1.2–3.7)	0.0123	2.4(1.2–4.6)	0.0107
Length of hospital stays (Within 2 year before index date)
No admission	Reference		Reference
1–6 days	1.0(0.8–1.2)	0.8784	1.1(0.8–1.3)	0.6600
7–13 days	1.1(0.8–1.5)	0.5221	0.9(0.5–1.7)	0.8386
> = 14 days	0.8(0.5–1.2)	0.2196	1.2(0.4–3.8)	0.7558
Co-morbidity
Asthma	1.0(0.8–1.2)	0.8817	0.9(0.7–1.1)	0.4529
Allergic rhinitis	1.3(1.1–1.5)	0.0003	1.3(1.1–1.6)	0.0006
Zoster	1.0(0.7–1.4)	0.9471	1.2(0.8–1.8)	0.2857
HBV infection	1.2(0.7–2.3)	0.5111	1.0(0.4–2.7)	0.9916
HCV infection	1.0(0.4–2.8)	0.9734	-	-
Diabetes mellitus	1.0(0.7–1.5)	0.9191	0.7(0.4–1.3)	0.2711
Gout	0.5(0.1–3.7)	0.5127	1.0(0.1–7.7)	0.9661
Cancer	1.3(0.5–3.2)	0.6107	0.6(0.1–2.9)	0.5088
Medication
Corticosteroids	1.2(0.9–1.7)	0.2210	1.1(0.7–1.8)	0.5795
NSAID	1.1(0.9–1.3)	0.4666	1.0(0.8–1.3)	0.8693
Antihistamines	1.4(1.2–1.6)	< .0001	1.4(1.2–1.7)	0.0004