Table 2

Determinants of flare after achieving LLDAS for the first time by Cox regression analyses

Variables	Univariate analysis			Multivariate analysis
Variables	HR	95% CI	P value	HR	95% CI	P value
Gender: female	0.86	0.31 to 2.40	0.769
Education level: tertiary	1.08	0.71 to 1.64	0.734
Age at disease onset (per year)*	0.99	0.96 to 1.01	0.168
Disease duration at recruitment (per year)†	1.01	0.98 to 1.06	0.471
Follow-up duration (per month)‡	1.00	0.96 to 1.04	0.978
Organ involvement§
Skin and mucous involvement	1.10	0.59 to 2.03	0.766
Arthritis	0.92	0.49 to 1.71	0.797
Polyserositis	1.25	0.58 to 2.70	0.569
LN	0.70	0.39 to 1.27	0.242
NPSLE	0.95	0.34 to 2.65	0.916
AIHA	1.08	0.39 to 3.02	0.885
Thrombocytopaenia	0.91	0.45 to 1.84	0.787
Leucopenia	0.60	0.32 to 1.12	0.108
PAH	3.59	1.10 to 11.75	0.035	3.79	0.86 to 16.69	0.078
Laboratories at first LLDAS¶
Anti-dsDNA positive	1.32	0.71 to 2.46	0.375
C3 (per 100 mg/L)	0.77	0.65 to 0.92	0.004	0.77	0.65 to 0.91	0.002
C4 (per 100 mg/L)	0.63	0.38 to 1.02	0.062
UTP (per mg)	1.00	0.99 to 1.01	0.785
Scr (per µmol/L)	1.00	0.98 to 1.01	0.758
Scores at first LLDAS¶
SLEDAI	1.21	0.98 to 1.50	0.077
PGA	1.65	0.78 to 3.46	0.187
Treatments
Pred daily dose at recruitment (per mg/day)	0.99	0.97 to 1.02	0.658
Pred daily dose at first LLDAS¶ (per mg/day)	0.93	0.79 to 1.10	0.404
HCQ**	0.93	0.29 to 3.01	0.906
IS**	1.54	0.62 to 3.79	0.350

*Years; disease onset defined as the date of the first symptom related to SLE.
†Years; disease duration at recruitment defined as time from disease onset to recruitment.
‡Duration from recruitment to the first visit of achieving LLDAS.
§Present ever during the course of disease before achieving LLDAS. The definitions for organ involvement are specified in the Definitions section.
¶Laboratory results, assessment scores and daily prednisone dose at the first visit of achieving LLDAS.
**HCQ or IS was used for at least 3 months from recruitment to the first visit of achieving LLDAS.
AIHA, autoimmune haemolytic anaemia; anti-dsDNA, anti-double-stranded DNA antibody; HCQ, hydroxychloroquine; IS, immunosuppressants; LLDAS, lupus low disease activity status; LN, lupus nephritis; NPSLE, neuropsychiatric SLE; PAH, pulmonary arterial hypertension; PGA, physician global assessment; pred, prednisone; Scr, serum creatinine; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; UTP, 24-hour urine total protein.