Table 3 Difference between the mean number of RTI episodes per year during the follow-up period and the number of episodes of RTI before inclusion in the study stratified according to smoking habits in the treated (specific extract of duck liver and heart) and untreated groups

Nonsmokers

-4.25 ± 1.75

-4.92 ± 1.63

-3.43 ± 1.54

0.001

Reference

Reference

Reference

Secondhand smokers

-4.16 ± 1.36

-4.69 ± 1.31

-3.38 ± 1.06

0.010

p = 0.749

p = 0.645

p = 0.973

Former smokers

-3.72 ± 0.99

-4.21 ± 0.91

-3.20 ± 0.79

0.011

p = 0.680

p = 0.920

p = 0.492

Current smokers

-3.90 ± 1.05

-4.59 ± 0.90

-3.23 ± 0.69

<0.001

p = 0.544

p = 0.365

p = 0.936

Overall p value among smoking habit classes

p = 0.899

p = 0.684

p = 0.895

-