Mazzaro 2000.

Methods	Generation of the allocation sequence: adequate (computer generated random sequence). Allocation concealment: unclear (not reported). Blinding: no blinding. Follow‐up: Adequate. Follow‐up was 12 months after treatment. They clearly reported that there had been no dropouts or withdrawals.
Participants	13 patients form Italy with cryoglobulinaemic glomerulonephritis and positive HCV‐RNA. Inclusion criteria: patients with diagnosed cryoglobulinaemic glomerulonephritis. Diagnosis was confirmed by kidney biopsy. All patients had positive HCV‐RNA diagnosed by enzyme‐linked immunosorbent assay (ELISA). Exclusion criteria: History of intravenous drug or alcohol abuse All patients had previously been treated with corticosteroids and cyclophosphamide and were after remission enrolled in the study. Group prednisolone: Male/Female: 2/4. Age (mean ± SD): 59 ± 11. Duration of disease (years): 4 ± 2.7. ALT (IU/L): 48 ± 27. HCV‐RNA copies/nl: 1.7 ± 2.9. Group interferon: Male/Female: 3/4. Age (mean ± SD): 64 ± 11. Duration of disease (years): 5.1 ± 3.0. ALT (IU/L): 44 ± 18. HCV‐RNA copies/nl: 2.1 ± 3.1.
Interventions	All patients received methyl‐prednisolone and cyclophosphamide in the acute phase. After six to nine months patients with stationary, but active disease were randomly assigned to either interferon or prednisolone. Prednisolone group: all patients received oral prednisolone 0.2 mg/kg/day for six months. Interferon group: all patients received lymphoblastoid interferon alpha‐n1 three million units three times/week for six months.
Outcomes	Purpura score, level of cryoglobulins, rheumatoid factor, creatinine, HCV‐RNA, ALT, and side effects. A negative HCV‐RNA (less than 10 copies/ml) were defined as complete response.
Notes	We wrote to the authors asking for more information regarding the trial which they kindly replied to. This trial reported that significantly more patients treated with interferon compared to prednisolone were having adverse events like fever, fatigue, and flu‐like syndrome but no numerical data were provided. They reported that cost of prednisone was 585 Euro and that the cost of interferon was 1950 Euro.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear