Table 4.

Multivariable analyses of impact of corticosteroid treatment, antiviral therapy and lymphocyte count on clinical outcomes

	Lower respiratory tract disease		Hypoxemia		Mechanical ventilation		Time to influenza- associated death*		Time to death*		Prolonged shedding†
Variable	OR (95% CI)	P	OR (95% CI)	P	OR (95% CI)	P	HR (95% CI)	P	HR (95% CI)	P	OR (95% CI)	P
Corticosteroid treatment
None	Reference		Reference		Reference		Reference		Reference		Reference
Low dose‡	0.3 (0.1-1.1)	0.10	1.3 (0.4-4.0)	0.50	0.4 (0.1-2.4)	0.90	0.5 (0.1-2.5)	0.40	1.1 (0.4-3.6)	0.85	0.5 (0.1-2.5)	0.11
High dose‡	0.8 (0.2-2.4)	0.60	0.9 (0.3-3.3)	0.69	0.2 (0.0-1.9)	0.27	0.9 (0.3-3.3)	0.89	1.1 (0.3-3.5)	0.87	3.3 (1.0-11)	0.05
URI antiviral therapy
No	Reference		Reference		Reference		Reference		Reference		Reference
Yes	0.04 (0-0.2)	<0.01	0.3 (0.1-0.9)	0.03	0.7 (0.2-3.3)	0.68	0.3 (0.1-1.4)	0.11	0.3 (0.1-1.1)	0.07	0.9 (0.3-3.0)	0.84
Lymphocyte count (cells/μl)
>300	Reference		Reference		Reference		Reference		Reference		Reference
100-300	2.0 (0.5-7.5)	0.93	0.9 (0.3-2.9)	0.33	0.7 (0.1-7.3)	0.24	2.0 (0.3-15)	0.48	1.9 (0.5-7.6)	0.64	0.4 (0.1-2.0)	0.14
< 100	4.3 (1.3-15)	0.04	2.6 (0.9-7.0)	0.05	6.4 (1.5-28)	<0.01	7.5 (1.5-37)	0.01	3.8 (1.1-13)	0.03	1.5 (0.4-5.2)	0.18

CI indicates confidence interval; HR, adjusted hazard ratio; OR, adjusted odds ratio; URI, upper respiratory tract infection.

Notes: Corticosteroid treatment, URI antiviral therapy and lymphocyte count were included as variable in all analyses. Multivariable models also included infection year and cell source for lower respiratory tract disease analysis, cell source and acute GVHD for hypoxemia analysis, acute GVHD for mechanical ventilation analysis, disease risk for time to influenza-associated death and time to death analyses and cell source for prolonged shedding analysis.

^*During the first 42 days following influenza diagnosis.

^†Defined as viral excretion > 14 days.

^‡Low dose: < 1 mg/kg or oral beclomethasone diproprionate. High dose: ≥1 mg/kg.