Table 1.
Baseline demographic and clinical characteristics of the study population
| Characteristic | No Decline in Kidney Function (Rate of eGFR Change >0 ml/min per year) (n = 1604) | Mild CKD Progression (eGFR Loss 0 to 1 ml/min per year) (n = 426) | Moderate CKD Progression (eGFR Loss 1 to 4 ml/min per year) (n = 1147) | Severe CKD Progression (eGFR Loss >4 ml/min per year) (n = 994) | P |
|---|---|---|---|---|---|
| Age (years; average ± SD) | 71.6 ± 9.8 | 73.0 ± 8.6 | 73.1 ± 8.8 | 72.9 ± 9.3 | 0.0116 |
| Race (n [%]) | |||||
| white | 1394 (87.0) | 376 (88.0) | 1006 (88.0) | 825 (83.0) | 0.0268 |
| black | 182 (11.0) | 36 (9.0) | 121 (10.0) | 155 (16.0) | 0.0077 |
| other | 28 (2.0) | 14 (3.0) | 20 (2.0) | 14 (1.0) | 0.4526 |
| Male gender (n [%]) | 1495 (93.0) | 399 (94.0) | 1076 (94.0) | 933 (94.0) | 0.4555 |
| Comorbid conditions (n [%]) | |||||
| hypertension | 1469 (92.0) | 388 (91.0) | 1075 (94.0) | 950 (95.0) | <0.0001 |
| diabetes | 649 (40.0) | 176 (41.0) | 537 (47.0) | 518 (52.0) | <0.0001 |
| CVD | 980 (61.0) | 258 (61.0) | 737 (64.0) | 703 (71.0) | <0.0001 |
| PAD | 155 (10.0) | 34 (8.0) | 141 (12.0) | 133 (13.0) | 0.0009 |
| cerebrovascular disease | 40 (2.5) | 7 (1.6) | 28 (2.4) | 27 (2.7) | 0.7070 |
| CLD | 642 (40.0) | 151 (35.0) | 466 (41.0) | 394 (40.0) | 0.8912 |
| hepatitis C | 42 (2.6) | 7 (1.6) | 15 (1.3) | 25 (2.5) | 0.3947 |
| dementia | 149 (9.3) | 38 (8.9) | 71 (6.2) | 96 (9.7) | 0.4665 |
| DMARDs (%)a | 485 (30.0) | 125 (29.0) | 333 (29.0) | 281 (28.0) | 0.2720 |
| NSAIDs (%)a | 1341 (84.0) | 357 (84.0) | 971 (85.0) | 837 (84.0) | 0.5521 |
| Initial eGFR (ml/min; average ± SD) | 52.9 ± 4.3 | 52.6 ± 4.4 | 53.2 ± 4.3 | 53.1 ± 4.3 | 0.8017 |
| Final eGFR (ml/min; average ± SD) | 54.9 ± 17.7 | 48.3 ± 13.9 | 44.8 ± 14.9 | 37.4 ± 15.9 | <0.0001 |
| Rate of eGFR change (ml/min per year; average ± SD)b | 3.5 ± 3.6 | −0.5 ± 0.3 | −2.4 ± 0.9 | −7.5 ± 3.9 | <0.0001 |
| Follow-up (years; mean ± SD)c | 4.6 ± 1.8 | 4.6 ± 1.8 | 4.4 ± 1.9 | 3.9 ± 2.0 | 0.0001 |
| Follow-up (years; median)c | 5.7 | 5.8 | 5.6 | 4.5 | – |
| Time between index and last eGFR (years; mean ± SD)d | 2.4 ± 0.4 | 2.5 ± 0.5 | 2.5 ± 0.3 | 2.4 ± 0.5 | <0.0001 |
| Time between index and last eGFR (years; median)d | 2.5 | 2.6 | 2.6 | 2.6 | – |
aLong-term use of DMARDs and NSAIDs was defined as use of medication for >120 days (3-month prescription with at least one refill).
bReflects the rate of change of eGFR per year calculated using an ordinary least squares (OLS) regression method fitted to all outpatient eGFR readings for each patient. The slope of the regression line describes the rate of change in kidney function (eGFR) over time.
cFollow-up time is the survival time between time 0 and censorship.
dDescribes the time between the index and the final eGFR during the assessment period.