Whole cohort N (%) | Initial IFN HIGH N (%) | Initial IFN LOW N (%) | Initial status Univariate analysis | Initial status Multivariate analysis | Stable IFN HIGH N (%) | Stable IFN LOW N (%) | Longitudinal status Univariate analysis | Longitudinal status Multivariate analysis | |

Any active renal disease | 61 (29.8) | 46 (35.7) | 15 (24.2) | OR 1.73 (0.89 to 3.52) p=0.11 | OR 1.17 (0.57 to 2.51) p=0.66 | 35 (41.2) | 8 (20.5) | OR 2.71 (1.15 to 6.69)p=0.027 | OR 1.47 (0.55 to 4.10) p=0.44 |

Proteinuria | 59 (28.8) | 44 (34.1) | 15 (24.2) | OR 1.62 (0.82 to 3.29) p=0.17 | OR 1.12 (0.54 to 2.38) p=0.77 | 33 (38.8) | 8 (20.5) | OR 2.45 (1.04 to 6.32)p=0.047 | OR 1.34 (0.50 to 3.74) p=0.56 |

Haematuria | 31 (15.1) | 26 (20.2) | 5 (8.1) | OR 2.88 (1.13 to 8.87)p=0.04 | OR 2.18 (0.82 to 6.91) p=0.14 | 20 (23.5) | 3 (7.7) | OR 5.68 (1.53 to 36.92)p=0.024 | OR 3.80 (0.93 to 25.71) p=0.10 |

Arthritis | 35 (17.1) | 28 (21.7) | 4 (6.5) | OR 4.02 (1.49 to 14.1)p=0.013 | OR 7.72 (2.41 to 31.92)p=0.002 | 18 (21.2) | 3 (7.7) | OR 3.22 (1.00 to 14.41)p=0.075 | OR 5.54 (1.42 to 29.96)p=0.024 |

Serositis | 7 (3.4) | 7 (5.4) | 2 (3.2) | OR 1.72 (0.40 to 11.80) p=0.51 | OR 1.61 (0.13 to 2.63) p=0.58 | 1 (1.2) | 2 (5.1) | OR 0.22 (0.01 to 2.37) p=0.22 | ## |

Skin disease | 62 (30.2) | 50 (38.8) | 9 (14.5) | OR 3.85 (1.82 to 8.96)p=0ยท0008 | OR 4.12 (1.83 to 10.13)p=0.001 | 35 (41.2) | 4 (10.3) | OR 3.85 (2.20 to 21.86)p=0.015 | OR 6.58 (2.13 to 25.5)p=0.002 |

Any haematological activity | 58 (28.3) | 44 (34.1) | 7 (11.3) | OR 4.06 (1.80 to 10.46)p=0.002 | OR 3.31 (1.40 to 8.80)p=0.010 | 29 (34.1) | 9 (23.1) | OR 1.72 (0.74 to 4.29) p=0.22 | OR 1.3 (0.50 to 3.54) p=0.60 |

Leucopenia | 42 (20.5) | 34 (26.4) | 4 (6.5) | OR 5.20 (1.94 to 18.04)p=0.003 | OR 4.60 (1.65 to 16.45)p=0.008 | 23 (27.1) | 4 (10.3) | OR 3.25 (1.14 to 11.74)p=0.04 | OR 2.90 (0.92 to 11.34) p=0.09 |

Haemolysis | 2 (1.0) | 1 (0.8) | 1 (1.6) | OR 0.47 (0.01 to 12.18) p=0.60 | ## | 1 (1.2) | 0 (0.0) | ## | ## |

Thrombocytopenia | 20 (9.8) | 14 (10.9) | 4 (6.5) | OR 1.76 (0.60 to 6.44) p=0.34 | OR 2.15 (0.77 to 6.32) p=0.77 | 8 (9.4) | 5 (12.8) | OR 0.71 (0.22 to 2.48) p=0.57 | OR 0.37 (0.09 to 1.52) p=0.16 |

Neurological disease | 3 (1.5) | 1 (0.8) | 1 (1.6) | OR 0.47 (0.02 to 12.19) p=0.60 | ## | 1 (1.2) | 2 (5.1) | OR 0.22 (0.01 to 2.37) p=0.22 | ## |

Low C3/C4 | 163 (79.5) | 109 (84.5) | 44 (71.0) | OR 2.44 (1.20 to 5.00)0.013 | OR 2.04 (0.94 to 4.40) p=0.07 | 73 (85.9) | 28 (71.8) | OR 2.39 (0.94 to 6.08)p=0.07 | OR 1.80 (0.61 to 5.18) p=0.28 |

High dsDNA | 142 (69.3) | 97 (75.2) | 37 (59.7) | OR 2.34 (1.27 to 4.55)p=0.007 | OR 1.53 (0.75 to 3.10) p=0.24 | 67 (78.8) | 26 (66.7) | OR 1.86 (0.79 to 4.33)p=0.015 | OR 1.17 (0.42 to 3.09) p=0.76 |

Bolded entries refer to results that are significant with p value <0.05.

## - unable to perform multivariate analysis including this variable due to low prevalance of variable in study population.

IFN, interferon; SLEDAI-2K, SLE Disease Activity Index.