TABLE 6

Factors Associated With ICU Admission in Patients Hospitalized With Influenza B

Univariate Analysis (n = 1510)Univariate Analysis by Health Statusa
No Underlying Condition (n = 684)Vaccine-Indicated Conditionb (n = 651)Other Underlying Condition (n = 175)
OR (95% CI)POR (95% CI)POR (95% CI)POR (95% CI)P
Boys1.13 (0.83–1.54).44cccccc
Age, y1.03 (0.99–1.06).10cccccc
Age group.05.01.13.59
 0–5 moReferenceReferenceReferenceReference
 6–23 mo1.28 (0.70–2.35).423.46 (1.26–9.49).020.33 (0.11–0.96).040.43 (0.11–1.70).23
 24–59 mo1.46 (0.82–2.58).202.64 (0.95–7.35).060.47 (0.18–1.21).120.62 (0.17–2.26).47
 5–9 y0.97 (0.53–1.77).921.70 (0.57–5.01).340.29 (0.11–0.78).010.57 (0.16–2.08).40
 ≥10 y1.91 (1.04–3.54).045.79 (1.91–17.57).0020.41 (0.15–1.13).081.13 (0.29–4.44).86
Health status.002
 No underlying conditionReferencedddddd
 Vaccine-indicated condition1.68 (1.20–2.35).003dddddd
 Other underlying condition2.00 (1.25–3.21).004dddddd
  • a Conducted due to detection of an interaction between age group and health status (P = .045) on multivariable analysis.

  • b For the 0–5 mo age group, a vaccine-indicated condition refers to an underlying condition for which influenza vaccination is particularly recommended in individuals aged ≥6 mo, and does not indicate that influenza vaccination should be given to this age group.

  • c Sex and age (in years) were not included in the multivariable model.

  • d N/A.