Figure 3. Primary Outcome in a Study of the Effect of Oral Methylprednisolone on Kidney Function Decline in Patients With IgA Nephropathy.

Hazard ratios and CIs were calculated with a Cox proportional hazards model with stratification according to region, baseline proteinuria, baseline estimated glomerular filtration rate, and kidney biopsy findings, with factors for trial group, subgroup, and the interaction between trial group and the subgroup variable. Ancestry was reported by the investigators. Proteinuria was 24-hour urinary protein.