(a).

MPO-ANCA	Cases (%)	Healthy controls (%)	OR (odds ratio)	CI (confidence interval)	p value (Fisher's exact)
(≥3 U/mL):
All	91 (21/23)	26 (6/23)	30	5.3–167	<0.001
<1 year	88 (15/17)	19 (3/16)	33	4.7–226	<0.001
1–4 years	87 (13/15)	13 (2/15)	42	5.2–347	<0.001
>4 years	69 (11/16)	25 (4/16)	6.6	1.4–31	0.03
(≥6 U/mL)
All	57 (13/23)	0 (0/23)	34∗	3.9–300∗	<0.001
<1 year	59 (10/17)	0 (0/16)	28∗	2.9–262∗	<0.001
1–4 years	7 (1/15)	0 (0/15)	1.1∗	0.1–20∗	1.0
>4 years	19 (3/16)	0 (0/16)	3.9∗	0.4–42∗	0.23