Table 3

Assessing the relationship between end stage lung disease and risk factors. Results from univariate analysis

Variable		Hazard ratio*	95% CI
Age at 1st assessment (years)		1.02	0.99 to 1.06
Sex	Male	1.00
	Female	0.68	0.27 to 1.74
Duration of disease from onset to 1st assessment (years)		0.89	0.71 to 1.11

System	Variable	Category	No (%)	Lung end point (n=24)	No lung end point (n=537)	Hazard ratio	95% CI
*Hazard ratios from Cox regression analysis adjusted for age, sex, and disease duration.
		Limited	324 (57.8)	11	313	1.00
Skin	Cutaneous type	Diffuse	237 (42.2)	13	224	1.65	0.71 to 3.85
		⩽6	167 (29.8)	3	164	1.00
		6–14	168 (29.9)	8	160	1.95	1.50 to 7.59
	Skin score	>14	226 (40.3)	13	213	2.68	0.74 to 9.71
		⩽60	151 (30.8)	15	136	18.19	3.53 to 93.82
		60–77	168 (34.2)	4	164	2.97	0.47 to 18.39
Lung	Diffusing lung capacity (Tlco) (%)	>77	172 (35.0)	2	170	1.00
		1–80	165 (32.9)	11	154	4.09	1.10 to 15.19
		81–100	173 (34.5)	9	164	2.36	0.62 to 9.00
	Forced vital capacity (%)	>100	163 (32.5)	3	160	1.00
		Normal	533 (97.1)	22	511	1.00
Heart	ECG	Abnormal	16 (2.9)	2	14	3.22	0.70 to 14.90
		1–70	172 (35.4)	9	163	1.53	0.59 to 3.96
		71–80	212 (43.6)	9	203	1.00
	Diastolic blood pressure (mm Hg)	>80	102 (21.0)	1	101	0.21	0.03 to 1.64
		⩽8.2	154 (33.9)	8	146	1.00
		8.3–9.0	153 (33.7)	5	148	0.74	0.23 to 2.30
Kidney	Serum creatinine (mg/l)	>9.0	147 (32.4)	8	139	0.80	0.26 to 2.50
		Absent	536 (95.5)	21	515	1.00
	Urine protein	Present	25 (4.5)	3	22	3.91	1.14 to 13.35
		Normal	508 (91.7)	22	486	1.00
Muscle	Creatine kinase	Raised	46 (8.3)	2	44	1.43	0.33 to 6.21
		⩽123	170 (33.5)	6	164	0.85	0.29 to 2.54
		124–134	165 (32.5)	7	158	0.80	0.25 to 2.51
General	Haemoglobin (g/l)	>134	173 (34.1)	8	165	1.00
		0.01–0.36	165 (32.5)	8	157	0.74	0.26 to 2.10
		0.37–0.40	204 (40.2)	4	200	0.24	0.07 to 0.82
	Packed cell volume	>0.40	139 (27.4)	9	130	1.00
		⩽10	172 (36.6)	8	164	1.00
		11–24	155 (33.0)	4	151	0.67	0.20 to 2.25
	ESR (mm/1st h)	⩾25	143 (30.4)	7	136	1.52	0.54 to 4.31
		Negative	442 (78.8)	20	422	1.00
Antibody markers	ACA	Positive	119 (21.2)	4	115	0.57	0.19 to 1.74
		Negative	462 (82.4)	19	443	1.00
	Antitopoisomerase	Positive	99 (17.7)	5	94	1.54	0.56 to 4.23