Relative risks (RR) according to treatment category
| Treatment* | RR (95% CI)† | p Value† |
|---|---|---|
| Only cyclophosphamide vs only rituximab | 4.61 (1.16 to 39.98) | 0.03 |
| Only cyclophosphamide vs both | 3.05 (1.40 to 7.35) | 0.003 |
| Only cyclophosphamide vs none | 1.48 (0.60 to 4.36) | 0.52 |
*The ‘only cyclophosphamide’ group was treated with cyclophosphamide but not with rituximab. The ‘only rituximab’ group was treated with rituximab but not with cyclophosphamide. ‘Both’ indicates a group that received cyclophosphamide and rituximab. ‘None’ indicates a group that did not receive cyclophosphamide or rituximab. Other immunosuppressive drugs were also administered in all of the groups.
†RR represents the risk of malignancy compared with the reference group. Calculated by exact Poisson regression analysis.