Table 3. Risk factors for serious infections.

Incident rate ratio (IRR) obtained from univariable and multivariable Poisson regression.

Variables	Univariable IRR (95%CI)	P value	Adjusted IRR (95% CI)	P value
Age (per 10 yr)	1.49 (1.24 to 1.80)	<0.001	1.46 (1.19 to 1.78)	<0.001
Male	0.78 (0.46 to 1.32)	0.34	0.83 (.50 to 1.42)	0.51
MPO	1.76 (1.03 to 3.02)	0.04	1.32 (0.73 to 2.37)	0.36
Time from diagnosis to rituximab (per yr)	0.97 (0.92 to 1.03)	0.30	0.97 (0.91 to 1.04)	0.41
Duration of continuos rituximab before remission (per mo)	0.79 (0.53 to 1.17)	0.24	0.99 (0.69 to 1.41)	0.94
PLEX	0.64 (0.29 to 1.41)	0.27	0.42 (0.19 to 0.96)	0.04
IgG < 400 mg/dL	2.40 (1.22 to 4.72)	0.01	2.13 (1.04 to 4.36)	0.04

Abbreviations: CI, confidence interval; Ig, immunoglobulin; mo, month; MPO, myeloperoxidase; PLEX, plasma exchange; yr, year.