Table 2. Hazard ratios (HRs) and 95% confidence intervals (CIs) associated with risk of active disease according to nondietary factors.

Factor	HRa	95% CI
Age (years)	0.98b	0.96–1.01
Duration of disease (years)	0.99	0.94–1.04
Habitual smoking	0.72	0.26–2.01
Lower education levelc (junior high school or lower)	1.20	0.48–3.00
Pregnancy after disease onset	0.93	0.43–2.02
Body mass index 25≤d	0.29	0.07–1.22
Dose of prednisolonee	1.44	0.88–2.34
SLICC/ACR DI scoref	1.11	0.86–1.43

Abbreviation: SLICC/ACR DI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

^aCox proportional hazards model was used to estimate HRs and 95% CIs; HRs were adjusted for age.

^bHR estimated for age only.

^cEducation level of high school or higher was defined as the referent category.

^dBody mass index <25 was defined as the referent category.

^ePrednisolone dose was categorized into the 4 dose levels shown in Table 1. Dose level was treated as a continuous variable.

^fSLICC/ACR DI score was treated as a continuous variable.