Influenza vaccine effectiveness in preventing admissions related to H3N2 influenza.

Positives admissions with influenza confirmed influenza by real time reverse transcription polymerase chain reaction (rtRT-PCR). Negatives admissions with a negative rtRT-PCR result for influenza. IVE influenza vaccine effectiveness. CI Confidence Interval.
a Strong evidence (P<0.002) of between hospital and between epidemiological week variability. Hospital and epidemiological week included as random effect parameters in the multilevel analysis to estimate influenza vaccine effectiveness adjusted by age (deciles), sex, number of outpatient consultations in the last three months, and previous administration of plain 23 polysaccharide pneumococcal vaccine.
b Moderate evidence of between hospital variability (P = 0.045) and of between epidemiological week variability (P = 0.015). Hospital and epidemiological week included as a random effect parameter in the multilevel analysis to estimate influenza vaccine effectiveness in this group, adjusted as in (a).
c Weak evidence of between hospital variability (P>0.05). Strong evidence (P = <0.001) of between epidemiological week variability. Epidemiological week included as a random effect parameter in the multilevel analysis to estimate split conventional influenza vaccine effectiveness in this age group, adjusted as in (a) with hospital included in the model as an indicator variable.
d Weak evidence of between hospital variability (P = 0.497). Strong evidence (P = <0.001) of between epidemiological week variability. Epidemiological week included as a random effect parameter in the multilevel analysis to estimate influenza vaccine effectiveness in this group, adjusted as in (a) with hospital included in the model as an indicator variable.
e Moderate evidence (P = 0.042) of between hospital variability and strong evidence (P = <0.001) of between epidemiological week variability. Hospital and epidemiological included as random effect parameters in a multilevel analysis to estimate influenza vaccine effectiveness adjusted as in (a).
Influenza vaccine effectiveness in preventing admissions related to H3N2 influenza.