Table 3.
Risk of ESKD and model discrimination by different systolic BP parameters in unadjusted and adjusted analyses
| Metric n=513a | Unadjusted HRb (95% CI) | Unadjusted c Statistic (95% CI) | Adjusted HRb,c (95% CI) | Adjusted c Statistic (95% CI) |
|---|---|---|---|---|
| Clinic systolic BP index at a single visit | 1.5 (1.3 to 1.8) | 0.61 (0.55 to 0.66) | 1.2 (1.0 to 1.4) | 0.89 (0.86 to 0.91) |
| Mean of all clinic systolic BP indices at up to two visits | 1.5 (1.3 to 1.8) | 0.61 (0.55 to 0.66), Referencea | 1.2 (1.0 to 1.4) | 0.89 (0.87 to 0.92), Referencea |
| Mean ABP wake systolic BP index | 1.6 (1.3 to 2.0) | 0.61 (0.56 to 0.67) | 1.3 (1.0 to 1.6) | 0.90 (0.85 to 0.91) |
| Mean ABP sleep systolic BP index | 1.4 (1.2 to 1.7) | 0.58 (0.52 to 0.64) | 1.2 (1.0 to 1.5) | 0.89 (0.86 to 0.91) |
| Mean of all clinic systolic BP indices at up to two visits + mean ABP wake systolic BP index | Clinic:1.3 (1.1 to 1.6); ABP:1.4 (1.1 to 1.8) | 0.62 (0.57 to 0.68) | Clinic:1.0 (0.8 to 1.3); ABP:1.3 (0.9 to 1.7) | 0.90 (0.86 to 0.92) |
HR, hazard ratio; 95% CI, 95% confidence interval; ABP, ambulatory BP.
a
No differences were noted in the c statistics of any metric compared with that for the reference group, which includes clinic systolic BPs at up to two sequential clinic visits.
b
HR reported for every 0.1 increase in systolic BP index.
c
Adjusted for age, sex, race, cause of CKD, body mass index z score, duration of CKD, urine protein-to-creatinine ratio, serum albumin, hemoglobin, antihypertensive use, and baseline eGFR (by bedside Schwartz); n=496 included because of missing covariates.