- Ugarte-Gil, Manuel;
- Hanly, John;
- Urowitz, Murray;
- Gordon, Caroline;
- Bae, Sang-Cheol;
- Romero-Diaz, Juanita;
- Sanchez-Guerrero, Jorge;
- Bernatsky, Sasha;
- Clarke, Ann;
- Wallace, Daniel;
- Isenberg, David;
- Rahman, Anisur;
- Merrill, Joan;
- Fortin, Paul;
- Gladman, Dafna;
- Bruce, Ian;
- Petri, Michelle;
- Ginzler, Ellen;
- Dooley, Mary;
- Ramsey-Goldman, Rosalind;
- Manzi, Susan;
- Jönsen, Andreas;
- van Vollenhoven, Ronald;
- Aranow, Cynthia;
- Mackay, Meggan;
- Ruiz-Irastorza, Guillermo;
- Lim, Sam;
- Inanc, Murat;
- Jacobsen, Søren;
- Peschken, Christine;
- Kamen, Diane;
- Askanase, Anca;
- Pons-Estel, Bernardo;
- Alarcón, Graciela;
- Kalunian, Kenneth
OBJECTIVE: To determine the independent impact of different definitions of remission and low disease activity (LDA) on damage accrual. METHODS: Patients with ≥2 annual assessments from a longitudinal multinational inception lupus cohort were studied. Five mutually exclusive disease activity states were defined: remission off-treatment: clinical Systemic Lupus Erythematosus Disease Activity Index (cSLEDAI)-2K=0, without prednisone or immunosuppressants; remission on-treatment: cSLEDAI-2K score=0, prednisone ≤5 mg/day and/or maintenance immunosuppressants; low disease activity Toronto cohort (LDA-TC): cSLEDAI-2K score of ≤2, without prednisone or immunosuppressants; modified lupus low disease activity (mLLDAS): Systemic Lupus Erythematosus Disease Activity Index-2K score of 4 with no activity in major organ/systems, no new disease activity, prednisone ≤7.5 mg/day and/or maintenance immunosuppressants; active: all remaining visits. Only the most stringent definition was used per visit. Antimalarials were allowed in all. The proportion of time that patients were in a specific state at each visit since cohort entry was determined. Damage accrual was ascertained with the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Univariable and multivariable generalised estimated equation negative binomial regression models were used. Time-dependent covariates were determined at the same annual visit as the disease activity state but the SDI at the subsequent visit. RESULTS: There were 1652 patients, 1464 (88.6%) female, mean age at diagnosis 34.2 (SD 13.4) years and mean follow-up time of 7.7 (SD 4.8) years. Being in remission off-treatment, remission on-treatment, LDA-TC and mLLDAS (per 25% increase) were each associated with a lower probability of damage accrual (remission off-treatment: incidence rate ratio (IRR)=0.75, 95% CI 0.70 to 0.81; remission on-treatment: IRR=0.68, 95% CI 0.62 to 0.75; LDA: IRR=0.79, 95% CI 0.68 to 0.92; and mLLDAS: IRR=0.76, 95% CI 0.65 to 0.89)). CONCLUSIONS: Remission on-treatment and off-treatment, LDA-TC and mLLDAS were associated with less damage accrual, even adjusting for possible confounders and effect modifiers.