GEE model (approach 2): Effect estimates for longitudinal change of lung function parameters in relationship with concentration (in 0.1 mg/m3) and duration (in quartz-years) of quartz dust exposure and co-variables. No. of subjects = 1343.

Table 4B: GEE model (approach 2): Effect estimates for longitudinal change of lung function parameters in relationship with concentration (in 0.1 mg/m³) and duration (in quartz-years) of quartz dust exposure and co-variables. No. of subjects = 1343.

	VC_max (liters)			FEV₁ (liters)			FEV₁/VC_max (%)
Covariable	Estimate	Std.Err	P > \|z\|	Estimate	Std.Err	P > \|z\|	Estimate	Std.Err	P > \|z\|
Approach 2
Quartz dust concentration^*	-0.097	0.023	< 0.001	-0.069	0.023	0.003	0.099	0.293	0.735
Duration of exposure^**	0.000	0.003	0.897	-0.002	0.003	0.537	-0.039	0.039	0.324
Height (in cm)	0.063	0.002	< 0.001	0.049	0.002	< 0.001	-0.056	0.025	0.023
Weight (in kg)	-0.005	0.001	< 0.001	-0.005	0.001	< 0.001	-0.008	0.010	0.454
Age ≤ 25	-0.036	0.004	< 0.001	-0.034	0.003	< 0.001	-0.118	0.039	0.002
Age > 25	-0.029	0.004	< 0.001	-0.032	0.003	< 0.001	-0.186	0.036	< 0.001
Non-German nationality^***	-0.162	0.045	< 0.001	-0.180	0.042	< 0.001	-1.197	0.487	0.014
Active smoker^***	-0.134	0.022	< 0.001	-0.082	0.021	< 0.001	0.181	0.256	0.480
Former smoker^***	-0.100	0.031	0.001	-0.015	0.028	0.584	0.903	0.347	0.009
Cumulative packyears	-0.004	0.001	0.003	-0.008	0.001	< 0.001	-0.098	0.016	< 0.001
Coking coal^***	0.217	0.031	< 0.001	0.050	0.030	0.090	-2.398	0.342	< 0.001
Custovit^***	0.133	0.012	< 0.001	-0.020	0.011	0.068	-2.475	0.167	< 0.001
Vitalograph^***	0.370	0.023	< 0.001	0.397	0.023	< 0.001	1.115	0.318	< 0.001
Year of measurements	0.013	0.004	< 0.001	0.024	0.004	< 0.001	0.264	0.044	< 0.001

Statistics: Hazard ratio with standard error, Wald test: z-value, two-sided p-value. ^*unit: In 0.1 mg/m3; ^** unit: Quartz-years; ^***Reference: German nationality; gas and flaming coal; non-smoker; body plethysmograph.