Table 4.

ICU Admission in Immunocompromised vs Nonimmunocompromised Adults Hospitalized With Laboratory-confirmed Influenza In the US Influenza Hospitalization Surveillance Network, 2011–2015

	aOR of ICU Admission	95% CI
Primary analysisa
18–49 years	0.83	.68–1.01
50–64 years	1.04	.88–1.22
65–79 years	1.25	1.06–1.48
≥80 years	1.35	1.06–1.73
Sensitivity analysisa,b
18–49 years	0.95	.80–1.12
50–64 years	1.10	.96–1.26
65–79 years	1.38	1.21–1.58
≥80 years	1.31	1.09–1.58

Effect modification by age group was only observed for ICU admission. Likelihood ratio test P = .004. Abbreviations: aOR, adjusted odds ratio; CI, confidence interval; ICU, intensive care unit.

^aControlling for age, sex, race/ethnicity, influenza vaccination, underlying medical conditions (smoking, obesity, chronic lung disease, cardiovascular disease, chronic metabolic disease, neuromuscular disorders, neurologic disorders, renal disease, liver disease), and influenza season. (Antiviral therapy was excluded because this was given upon or after ICU admission for most patients receiving intensive care.)

^bIncluding receipt of steroid therapy in the immunocompromised group.