| Risk factor | Risk of relapse | Level of evidence | Reference |
| A fourfold rise in C ANCA/PR3 ANCA titre | RR 42.5 (95% CI 9.48 to 180.8) | 3 | Boomsma et al 200029 |
| Chronic nasal carriage of Staphylococcus aureus* | RR 7.16 (95% CI 1.63 to 31.50); p = 0.009 | 2B | Stegeman et al 199433 |
| Creatinine clearance >60 ml/min | RR 2.94 (95% CI 1.27 to 6.67); p = 0.01 | 3 | Stegeman et al 199433 |
| The presence of ANCA at diagnosis | RR 2.89 (95% CI 1.12 to 7.45) | 1B | Stegeman et al 199616 |
| Cardiac involvement at diagnosis | RH 2.87 (95% CI 1.09 to 7.58); p = 0.03 | 3 | Koldingsnes and Nossent 200323 |
| Cumulative cyclophosphamide dose <10 g in the first 6 months | RH 2.83 (95% CI 1.33 to 6.02); p = 0.007 | 3 | Koldingsnes and Nossent 200323 |
| Prednisolone ⩾20 mg/day for <2.75 months | RH 2.41 (95% CI 1.12 to 5.21); p = 0.03 | 3 | Koldingsnes and Nossent 200323 |
| Co-trimoxazole as adjuvant to remission maintenance therapy | RR 0.32 (95% CI 0.13 to 0.79) | 1B | Stegeman et al 199616 |
*Nasal carriage of Staphylococcus aureus tended to decrease the relapse rate in Pavone et al;32 this was not statistically significant.
ANCA, antineutrophil cytoplasm antibody; C, cytoplasmic; PR3, proteinase 3; RH, relative hazard; RR, relative risk.