Table 1.

Characteristics of ESRD cases and controls at study entry.

		Cases1 N = 907		Controls1 N = 3622		P
		N	%	N	%
Age (years)	< 40	424	46.8	1644	45.4
	40–50	483	53.2	1978	54.6	.46
Gender	Male	585	64.5	2333	64.4
	Female	322	35.5	1289	35.6	.96
Country	Germany	726	80.0	2890	79.8
	Austria	181	20.0	732	20.2	.87
Education (years)	- 10	603	66.5	1998	55.2
	> 10	304	33.5	1624	44.8	< .001
Smoking	Never	340	37.5	1528	42.2
	Current	277	30.5	694	19.2
	Ex-smoker	290	32.0	1400	38.6	< .001
Alcohol	Seldom	757	83.5	1857	51.3
	Often	150	16.5	1765	48.7	. < .001
History of conditions, diseases
Diabetes mellitus	No	748	82.5	3572	98.6
	Yes	159	17.5	50	1.4	< .001
Hypertension	No	134	14.8	3253	89.8
	Yes	773	85.2	369	10.2	< .001
Renal diseases	No	25	2.8	3448	95.2
	Yes	882	97.2	174	4.8	< .001
Urinary tract infections	No	802	88.4	3478	96.0
	Yes	105	11.6	144	4.0	< .001
Family history: chronic renal disease	No	697	76.9	3425	94.6
	Yes	210	23.1	197	5.4	< .001
Migraine	No	766	84.5	3250	89.7
	Yes	141	15.5	372	10.3	< .001
Headache	No	656	72.3	2728	75.3
	Yes	251	27.7	894	24.7	.06
Menstruation problems	No	233	25.7	937	25.9
	Yes	89	9.8	352	9.7
	n.a.	585	64.5	2333	64.4	.99
Arthritic complaints	No	828	91.3	3418	94.4
	Yes	79	8.7	204	5.6	< .001
Chronic back pain	No	710	78.3	2866	79.1
	Yes	197	21.7	756	20.9	.58
Psychological/neurological problems	No	829	91.4	3397	93.8
	Yes	78	8.6	225	6.2	.01
History of treatment
Anti-rheumatic treatment	No	892	98.4	3600	99.4
	Yes	15	1.6	22	0.6	< .01
Immuno-suppressive therapy	No	866	95.5	3617	99.9
	Yes	41	4.5	5	0.1	< .001
Drug treatment against cancer	No	889	98.0	3605	99.5
	Yes	18	2.0	17	0.5	< .001
Long-term treatment with antibiotics	No	854	94.2	3526	97.4
	Yes	53	5.8	96	2.7	.000
Complaints (subjectively compared with other persons in the same age span)
Gastrointestinal problems	No, rare	577	63.6	2550	70.4
	Similar/more	330	36.4	1072	29.6	< .001
Cardiovascular problems	No, rare	610	67.3	3041	84.0
	Similar/more	297	32.7	581	16.0	< .001
Vomiting	No, rare	612	67.5	3187	88.0
	Similar/more	295	32.5	435	12.0	< .001
Depression	No, rare	719	79.3	3172	87.6
	Similar/more	188	20.7	450	12.4	< .001
Anxiety	No, rare	762	84.0	3259	90.0
	Similar/more	145	16.0	363	10.0	< .001
Sleeplessness	No, rare	542	59.8	2821	77.9
	Similar/more	365	40.2	801	22.1	< .001
Fatigue	No, rare	333	36.7	2490	68.8
	Similar/more	574	63.3	1132	31.2	< .001
Irritability	No, rare	505	55.7	2376	65.6
	Similar/more	402	44.3	1246	34.4	< .001
Stress	No, rare	459	50.6	1713	47.3
	Similar/more	448	49.4	1909	52.7	< .001
Eating problems	No, rare	752	82.9	3368	93.0
	Similar/more	155	17.1	254	7.0	< .001
History of exposures at work site
Heavy metal	No	750	82.7	3216	88.8
	Yes	157	17.3	406	11.2	< .001
Other metal dust	No	765	84.3	3240	89.5
	Yes	142	15.7	382	10.5	< .001
Special silicates2	No	847	93.4	3431	94.7
	Yes	60	6.6	191	5.3	.11
Other silicates3	No	796	87.8	3375	93.2
	Yes	111	12.2	247	6.8	< .001
Solvents	No	751	82.8	3188	88.0
	Yes	156	17.2	434	12.0	< .001
Welding & soldering fumes	No	797	87.9	3384	93.4
	Yes	110	12.1	238	6.6	< .001

¹ Deviations from the total number of cases and controls are due to missing information

² e.g. quartz, silicon dioxide, fibre glass, silicone

³ e.g. sand, cement, coal, grain dust