Table 2. Clinical factors associated with the 1-year TB incidence during the observation period.

	Univariable analysis		Multivariable analysis a
	HR (95% CI)	P-value	Adjusted HR (95% CI)	P-value
Age (per 5-year increment)	0.95 (0.82–1.10)	0.475	b
Male sex	1.40 (0.51–3.82)	0.513	b
Disease duration (per 5-year increment)	0.95 (0.55–1.64)	0.845	b
SLE	2.54 (0.99–6.55)	0.054	3.10 (1.24–7.75)	0.016
High-risk subgroup	8.62 (3.48–21.35)	<0.001	13.95 (5.61–34.64)	<0.001
Initial steroid dose at baseline (≥60 mg/day of prednisone vs. a lower dose) c	0.92 (0.39–2.18)	0.924	b
Concomitant oral cyclophosphamide	0.42 (0.003–3.04)	0.485	b
Concomitant cyclophosphamide pulse	1.47 (0.43–5.00)	0.535	b
Concomitant mycophenolate mofetil	2.16 (0.63–7.38)	0.219	b
Concomitant cyclosporine	0.69 (0.09–5.17)	0.718
Concomitant methotrexate	0.72 (0.10–5.33)	0.747
Concomitant steroid pulse	2.38 (0.96–5.89)	0.061	1.55 (0.63–3.80)	0.336
Mean steroid dose used during the prior 6 months, mg/day d	1.04 (1.01–1.06))	0.007	1.02 (0.99–1.05)	0.201
Duration of high-dose steroid treatment, day	1.01 (1.006 to 1.013)	<0.001	1.01 (1.004 to 1.013)	<0.001
Baseline lymphopenia e	1.26 (0.49–3.25)	0.632	b

CI, confidence interval; HR, hazard ratio; SLE, systemic lupus erythematosus; TB, tuberculosis.

^a Model included the clinical factors that showed a significant association (P < 0.1) in univariable analyses, and was adjusted for clustering.

^b Not included in the multivariable model as a covariate.

^c Dose was calculated after excluding the dose of the concomitant steroid pulse treatment.

^d Based on the dose of prednisone.

^e Defined as <800 lymphocytes per microliter.