HCQ reduction versus maintenance | HCQ discontinuation versus maintenance | |||||
No. of patients | Absolute flare rate/100 person-years (95% CI) | Adjusted HR (95% CI)* | No. of patients | Absolute flare rate/100 person-years (95% CI) | Adjusted HR (95% CI)* | |
Main analysis | 1342 | 40.0 (36.4 to 43.9) vs 31.9 (29.0 to 35.1) | 1.20 (1.04 to 1.38) | 966 | 41.3 (36.7 to 46.4) vs 30.0 (26.7 to 33.6) | 1.56 (1.31 to 1.86) |
Stratified analyses: | ||||||
Low disease activity‡ state at time-zero | ||||||
Yes | 815 | 37.5 (33.2 to 42.4) vs 27.8 (24.5 to 31.6) | 1.32 (1.10 to 1.60) | 592 | 35.5 (30.4 to 41.3) vs 26.6 (22.8 to 30.9) | 1.62 (1.28 to 2.05) |
No | 527 | 43.9 (38.0 to 50.6) vs 39.8 (34.3 to 46.1) | 1.04 (0.84 to 1.29) | 374 | 53.6 (44.7 to 64.2) vs 36.4 (30.5 to 43.5) | 1.60 (1.22 to 2.09) |
Remission† at time-zero | ||||||
Yes | 196 | 26.2 (20.1 to 34.1) vs 13.2 (9.5 to 18.4) | 2.14 (1.34 to 3.42) | 133 | 24.7 (17.7 to 34.6) vs 12.2 (8.0 to 18.8) | 2.77 (1.46 to 5.26) |
No | 1146 | 46.3 (41.9 to 51.1) vs 41.7 (37.8 to 46.0) | 1.14 (0.98 to 1.32) | 833 | 47.9 (42.3 to 54.2) vs 39.2 (35.0 to 43.9) | 1.50 (1.25 to 1.81) |
*Adjusted for sex, race, age at SLE diagnosis, education, geographic residence and the following variables assessed at time-zero: SLE duration, renal damage according to SLICC Damage Index, body mass index, smoking, prednisone, immunosuppressives and biologics. The main analysis was additionally adjusted by disease activity at time-zero.
†Remission was defined as SLEDAI-2K=0 and no prednisone or immunosuppressives use during the last year.
‡Low disease activity state was defined as SLEDAI-2K <4 and current prednisone dose ≤7.5 mg/day.
HCQ, hydroxychloroquine; SLE, systemic lupus erythematosus; SLEDAI-2K, SLE Disease Activity Index-2000; SLICC, Systemic Lupus International Collaborating Clinics.