Table 1

Crude and adjusted odds ratios for an acute episode of low respiratory tract or cardiac disease or death during an influenza epidemic in vaccinees and non-vaccinees

Study population and analysisAdjusted for:Odds ratio (95% CI)
*MLR, multivariable logistic regression analysis; †MCLR, multivariable conditional logistic regression.
Adult patients (18–102 y, n=1696) Conventional control: MLR*Crude value1.14 (0.84 to 1.55)
+ age (in years)0.87 (0.64 to 1.20)
+ disease (asthma/COPD)0.82 (0.59 to 1.13)
+ GP visits (in number)0.76 (0.54 to 1.05)
+ remaining factors0.76 (0.54 to 1.06)
Elderly patients (65–102 y, n=630) Conventional control: MLRCrude value0.57 (0.35 to 0.93)
+ age (in years)0.56 (0.35 to 0.92)
+ disease (asthma/COPD)0.53 (0.32 to 0.87)
+ GP visits (in number)0.50 (0.30 to 0.83)
+ remaining factors0.50 (0.29 to 0.83)
Younger patients (18–64 y, n=1066) Conventional control: MLRCrude value1.27 (0.84 to 1.94)
+ age (in years)1.11 (0.73 to 1.70)
+ disease (asthma/COPD)1.08 (0.70 to 1.66)
+ GP visits (in number)0.94 (0.61 to 1.47)
+ remaining factors0.94 (0.60 to 1.45)
Quasi-experiment (18–64 y, n=676) Conventional control: MCLR†Matched crude value0.90 (0.53 to 1.52)
+ age/ disease/GP visits0.89 (0.52 to 1.54)
+ remaining factors
Younger patients (18–64 y, n=1066) Propensity score + MCLR†Matched crude value0.87 (0.56 to 1.35)
+ age/ disease/GP visits0.86 (0.55 to 1.35)
+ remaining factors