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Table 5 Linear mixed effect models of sputum cells

From: Acute effects of cigarette smoking on inflammation in healthy intermittent smokers

Independent variable

Time interval

B

95% CI

P value

Log (total cells, 106/ml)

0–3 hours

0.075

-0.15–0.30

0.52

Log (neutrophils, % and 106/ml)

    

%

0–3 hours

-0.17

-0.34 – -0.00

0.07

number

0–3 hours

-0.22

-0.49–0.30

0.11

%

3–12 hours

0.03

-0.02–0.07

0.27

number

3–12 hours

0.13

0.04–0.22

0.007

Log (macrophages, % and 106/ml)

    

%

0–3 hours

0.12

-0.01–0.25

0.08

number

0–3 hours

0.13

-0.11–0.36

0.31

Log (eosinophils, % and 106/ml)

    

%

0–6 hours

-0.22

-0.71–028

0.39

number

0–6 hours

-0.12

-0.30–0.06

0.20

%

3–6 hours

-0.84

-3.63–1.96

0.57

number

3–6 hours

-0.31

-1.35–0.73

0.57

Log (lymphocytes, % and 106/ml)

    

%

0–3 hours

-0.28

-0.59–0.02

0.08

number

0–3 hours

-0.26

-0.42–-0.11

0.004

%

3–12 hours

0.19

0.06–0.31

0.006

number

3–12 hours

0.23

0.09–0.36

0.002

  1. The time intervals of the above parameters were selected based on visual inspection of the plots. The slopes of the parameters were estimated using linear mixed effect models [11] by including the variables time (hours), smoking (yes or no) and their interaction. B: regression coefficient for the variable time (for further information see the method section).