Table 4.
Risk of kidney disease progression using the kidney biopsy chronicity score
| Chronicity Scorea | N | Events per 100 person-yr | Model 1 HR [95% CI] | Model 2 HR [95% CI] | Model 3 HR [95% CI] |
|---|---|---|---|---|---|
| Per one-point change | 654 | 12.1 | 1.28 [1.22 to 1.33] | 1.23 [1.17 to 1.30] | 1.19 [1.12 to 1.27] |
| Minimal chronic changes (0–1) | 199 | 3.6 | — | — | — |
| Mild chronic changes (2–4) | 168 | 8.1 | 2.02 [1.17 to 3.48] | 1.72 [0.97 to 3.06] | 1.53 [0.85 to 2.75] |
| Moderate chronic changes (5–7) | 146 | 17.3 | 4.24 [2.55 to 7.04] | 3.81 [2.20 to 6.59] | 2.92 [1.61 to 5.31] |
| Severe chronic changes (≥8) | 141 | 39.6 | 8.67 [5.35 to 14.1] | 6.09 [3.51 to 10.6] | 4.42 [2.37 to 8.22] |
Shown are HRs (95% CIs) per one-point increase in the score (range from zero to ten) or compared to the reference group of minimal chronic changes. Model 1 is unadjusted. Model 2 is Model 1 stratified by site and adjusted for age, sex, race, log-transformed proteinuria, primary clinicopathologic diagnosis, and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker medication use. Model 3 includes Model 2 and adjusts for eGFR. HR, hazard ratio; 95% CI, 95% confidence interval; —, reference group.
Chronicity score is calculated by adding scores of global glomerulosclerosis (zero to three), interstitial fibrosis and tubular atrophy (zero to three), and arterial sclerosis (zero to one). Interstitial fibrosis and tubular atrophy are counted twice, because interstitial fibrosis and tubular atrophy are scored separately in the proposal by Sethi et al.16 Arterial sclerosis is given a score of zero for none/mild and one for moderate/severe lesions.