Table 2.
MDHR for time-to-event outcomes and MDDS for comparisons within disease type (n=600) and overall (n=2400)
| Outcome | Event rates per person year | MDHR* for n=600 (300/group) | MDHR* for 1=2400 (1200/group) |
|---|---|---|---|
| Time to ESKD or death* | 0.03-0.08 | 1.7 to 2.6 | 1.5 to 1.9 |
| Time to loss of 50% eGFR from baseline* | 0.04-0.15 | 2.1 to 7.3 | 1.8 to 3.6 |
| Time to complete remission of proteinuria (<0.3 g/d)*^ | 0.20-0.70 | 1.6 to 2.3 | 1.4 to 1.9 |
| Outcome | SD of subgroup | MDDS+ for n=600 (300/group) | MDDS+ for n=2400 (1200/group) |
| eGFR slope+ (mL/min/1.73 m2 per year) | 18.4-26.4 | 4.2-6.1 | 2.1-3.0 |
| eGFR (mL/min/1.73 m2) repeated measures++ | 13.5-22.6 | 2.8-4.6 | 1.4-2.3 |
| UPCR (mg/mg) repeated measures++ | 2.4-4.5 | 0.4-0.8 | 0.2-0.4 |
MDHR (minimum detectable hazard ratio) is based on the following assumptions: Patient follow-up time of 2 years for more common events (loss of 50% eGFR from baseline and complete remission of proteinuria). Patient follow-up time of 10 years for more rare events (ESKD or death); a loss to follow-up rate at an average rate of 0.1 per year, 80% power, alpha=0.05, an intra-cluster correlation of 0.05, and the between-site normalized standard deviation of site sample sizes of 0.15. Event rates per person year represent ranges over the four disease types.
MDDS (minimum detectable difference in slopes) based on differences between groups in mean person-specific slopes of eGFR values. Slopes are interpreted as eGFR change per year; SD of disease-specific eGFR slopes: MCD 20.5, FSGS 26.4, MN 24.2, and IgAN 18.4.
MDDS for eGFR and UPCR repeated continuous outcomes are based on differences between groups in mean slopes of eGFR and UCPR values. Slopes are interpreted as eGFR or UPCR change per year; SD of disease-specific eGFR: MCD 22.6, FSGS 15.6, MN 13.5, and IgAN 15.8. SD of disease-specific UPCR: MCD 4.5, FSGS 3.0, MN 3.6, and IgAN 2.4.
Group sizes for time-to-complete remission of proteinuria excluded 1/3 of the group who were in remission at enrollment.
Abbreviations: eGFR, estimated glomerular filtration rate; ESKD, end-stage kidney disease; FSGS, focal segmental glomerulosclerosis; IgAN, immunoglobulin A nephropathy; MCD, minimal change disease; MN, membranous nephropathy; SD, standard deviation.