METHODS: Patients aged 18 years or older with SLE were followed up from May 1, 2013, to Dec 31, 2020 in a prospective, multinational, longitudinal cohort study. Patients were recruited from 25 centres in 12 countries. Multi-failure time-to-event analyses were used to assess the effect of sustained LLDAS on irreversible damage accrual (primary outcome; measured with the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index) and flare (key secondary outcome; measured with the SELENA Flare Index), with dose exposure and threshold effects studied. Sustained LLDAS or remission were defined as two or more consecutive visits over at least 3 months in the respective state. This study is registered with ClinicalTrials.gov, NCT03138941.

FINDINGS: 3449 patients were followed up for a median of 2·8 years (IQR 1·1-5·6), totalling 37 662 visits. 3180 (92·2%) patients were women, and 3031 (87·9%) were of Asian ethnicity. 2506 (72·7%) patients had sustained LLDAS at least once. Any duration of sustained LLDAS or remission longer than 3 months was associated with reduced damage accrual (LLDAS: hazard ratio 0·60 [95% CI 0·51-0·71], p<0·0001; remission: 0·66 [0·57-0·76], p<0·0001) and flare (LLDAS: 0·56 [0·51-0·63], p<0·0001; remission: 0·66 [0·60-0·73], p<0·0001), and increasing durations of sustained LLDAS corresponded to increased protective associations. Sustained DORIS remission or steroid-free remission were less attainable than LLDAS.

INTERPRETATION: We observed significant protective associations of LLDAS and remission against damage accrual and flare, establish a threshold of 3 months sustained LLDAS or remission as protective, and demonstrate deepening protection with longer durations of sustained LLDAS or remission.

METHODS: Data from a 12-country longitudinal SLE cohort, collected prospectively between 2013 and 2020, were analysed. SLE patients with mSACQ defined as the state with serological activity (increased anti-dsDNA and/or hypocomplementemia) but without clinical activity, treated with ≤7.5 mg/day of prednisolone-equivalent GCs and not-considering duration, were studied. The risk of subsequent flare or damage accrual per 1 mg decrease of prednisolone was assessed using Cox proportional hazard models while adjusting for confounders. Observation periods were 2 years and censored if each event occurred.

RESULTS: Data from 1850 mSACQ patients were analysed: 742, 271 and 180 patients experienced overall flare, severe flare and damage accrual, respectively. Tapering GCs by 1 mg/day of prednisolone was not associated with increased risk of overall or severe flare: adjusted HRs 1.02 (95% CI, 0.99 to 1.05) and 0.98 (95% CI, 0.96 to 1.004), respectively. Antimalarial use was associated with decreased flare risk. Tapering GCs was associated with decreased risk of damage accrual (adjusted HR 0.96, 95% CI, 0.93 to 0.99) in the patients whose initial prednisolone dosages were >5 mg/day.

METHODS: We analysed data from 2930 patients with SLE across 13 countries, collected over 38 754 clinic visits between 2013 and 2020. Clinic visit records were converted to panel data with 1-year intervals. The time-adjusted mean disease activity, termed AMS, was calculated. The yearly change in [Formula: see text], denoted as [Formula: see text], was regressed onto [Formula: see text] and other potential predictors using random-effects models. Some variables were split into a person-mean component to assess between-patient differences and a demeaned component to assess within-patient variability.

RESULTS: Overall, variability in SLE disease activity exhibited stabilisation over time. A significant inverse relationship emerged between a patient's disease activity in a given year and variability in disease activity in the subsequent year: a 1-point increase in person-mean disease activity was associated with a 0.27-point decrease (95% CI -0.29 to -0.26, p<0.001) in subsequent variability. Additionally, a 1-point increase in within-patient disease activity variability was associated with a 0.56-point decrease (95% CI -0.57 to -0.55, p<0.001) in the subsequent year. Furthermore, each 1-point increase in the annual average time-adjusted mean Physician Global Assessment was associated with a 0.08-point decrease (90% CI -0.13 to -0.03, p=0.002) in disease activity variability for the following year. Prednisolone dose and the duration of activity in specific organ systems exhibited negative and positive associations, respectively, with disease activity variability in the subsequent year. Patients from less affluent countries displayed greater disease activity variability compared with those from wealthier nations.

METHODS: Flare was defined using the Safety of Estrogens in Lupus Erythematosus National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI flare index), and PAD was defined as an SLEDAI-2K score of ≥4, excluding serology only, on two or more consecutive visits with a maximum six-month interval. Multivariable logistic regression was used to develop predictive models for flare and PAD, which were tested in an independent validation subset.

RESULTS: Among 3,811 patients over 2.8 (interquartile range 1.0-5.3) years of follow-up, 2,142 (56.2%) experienced flare and 1,786 (46.9%) had PAD, with 368 (9.7%) experiencing PAD but not flare. The most common flare features were nephritis and arthritis, whereas PAD was most commonly characterized by renal or mucocutaneous activity. After adjusting for prednisone dose and use of antimalarials and immunosuppressants, low gross domestic product in country of residence, smoking, arthritis, nephritis, and low complement levels were predictive for flare, whereas being in a low disease activity state for ≥50% of follow-up time (LLDAS50) was a protective factor. Renal activity and higher time-adjusted mean SLEDAI-2K were predictive of PAD, whereas LLDAS50 was protective. The models developed gave 72.1% and 83.8% correct classification of flare and PAD, respectively, in the validation cohort.