Table 4.

Univariable and multivariable Cox regression analysis

	Univariable model		Multivariable model
	Unadjusted HR (95% CI)	P value	Initial model (n=155)	P value	Final model (n=169)	P value
			Adjusted HR (95% CI)		Adjusted HR (95% CI)
LN status		0.40		0.91		0.88
No	1.00		1.00		1.00
Yes	1.61 (0.53 to 4.92)		1.09 (0.25 to 4.79)		0.91 (0.27 to 3.06)
Gender		0.76
Male	1.00
Female	0.79 (0.18 to 3.57)
Age (years)	1.01 (0.97 to 1.04)	0.74
ATSI status		0.73
No	1.00
Yes	0.70 (0.09 to 5.38)
Location		0.60
Metropolitan	1.00
Regional	1.33 (0.45 to 3.97)
SLE comorbidity index	1.12 (1.03 to 1.23)	0.008
Modified SLE comorbidity index*	1.14 (1.04 to 1.24)	0.007	1.14 (0.97 to 1.33)	0.12	1.13 (1.02 to 1.25)	0.018
SLEDAI score	1.04 (0.99 to 1.09)	0.10	0.97 (0.89 to 1.06)	0.51
Prednisone dosage (per 5 mg)	1.21 (1.08 to 1.36)	0.001	1.22 (1.05 to 1.42)	0.008	1.21 (1.07 to 1.37)	0.003
Creatinine (per 100 µmol/L)	1.22 (1.04 to 1.44)	0.015	1.16 (0.92 to 1.46)	0.21
Urine protein:creatinine ratio† (n=118)	1.27 (1.05 to 1.55)	0.016
Lupus duration (years)	0.93 (0.85 to 1.02)	0.13	0.93 (0.84 to 1.04)	0.20
Number of immunosuppressant agents (continuous)‡	1.38 (0.91 to 2.11)	0.13	1.03 (0.54 to 1.98)	0.92
Number of immunosuppressant agents‡		0.16
<2	1.00
2+	2.32 (0.71 to 7.54)

*SLE comorbidity index score excluding LN contribution.

†Urine protein:creatinine ratio was not included in the multivariate model due to large number of missing values (n=55).

‡Number of immunosuppressant agents other than prednisone.

ATSI, Aboriginal and Torres Strait Islander; LN, lupus nephritis; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index.