Table 5.

Analysis of the health effects of toner exposure with adjustment for confounders (model 3)

Parameters (unit)	Difference in yearly change in each parameter between the toner-handling group and non-toner-handling group				Yearly change in each parameter of the non-toner-handling group
	Estimate	95% CI		P-value	Estimate	95% CI		P-value	AIC
Respiratory function tests
VC (l)	−0.001	− 0.004	0.001	0.294	−0.01	− 0.01	− 0.01	< 0.001	− 5289.3
%VC (%)	− 0.04	− 0.1	0.02	0.188	0.2	0.1	0.2	< 0.001	73,416.2
FEV1 (l)	0.00003	−0.002	0.002	0.982	−0.02	−0.02	− 0.02	< 0.001	− 9986.4
%FEV1 (%)	0.02	−0.05	0.08	0.616	0.1	0.09	0.2	< 0.001	74,397.2
FEV1/FVC (%)	0.004	−0.03	0.04	0.843	−0.3	−0.3	− 0.3	< 0.001	60,385.0
%FEV1/FVC (%)	0.02	−0.03	0.06	0.510	−0.09	−0.1	− 0.05	< 0.001	65,542.7
V25 (l/s)	0.001	−0.003	0.005	0.607	−0.03	−0.03	− 0.03	< 0.001	3467.3
%V25 (%)	0.02	−0.1	0.2	0.781	−0.4	−0.6	− 0.3	< 0.001	101,019.6
Biomarkers
CRP (mg/dl)	0.0004	−0.002	0.003	0.809	0.0004	−0.002	0.003	0.720	3574.3
IgE (IU/ml)	4.8	−1.0	10.6	0.107	−1.6	−6.1	3.0	0.500	174,528.7
8-OHdG/Creatinine (ng/mg)	−0.009	−0.03	0.006	0.235	0.03	0.02	0.05	< 0.001	44,980.9

In model 3, dependent variables consisted of the parameters of respiratory function tests and the values of biomarkers. We used the higher goodness-of-fit model in models 1 and 2 and adjusted the model using age at baseline, body mass index, smoking, asthma, allergic rhinitis, pneumonia, sinusitis, non-toner-handling work, and organic solvent-handling work as confounding factors

CI confidence interval, AIC Akaike’s Information Criterion, VC vital capacity, %VC percentage of VC to predicted VC value, FEV₁ forced expiratory volume in 1 s, %FEV₁ percentage of FEV₁ to predicted FEV₁ value, FEV₁/FVC percentage of forced expiratory volume in 1 s, %FEV₁/FVC percentage of FEV₁/FVC to predicted FEV₁/FVC value, V25 maximal expiratory flow at 25% forced VC, CRP C-reactive protein, IgE immunoglobulin E, IL interleukin, IFN-γ interferon-gamma, 8-OHdG 8-hydroxy-2′-deoxyguanosine