Table 1.
Baseline characteristics of the study population by eGFR reporting cohort
| Characteristic | All Patients (n=82,993) | eGFR Reporting Cohort | ||
|---|---|---|---|---|
| Pre-Reporting (n=66,323) | Post-Reporting (n=16,670) | P Valuea | ||
| Mean age ± SD (yr) | 71.5 ± 12.3 | 71.5 ± 12.2 | 71.3 ± 12.8 | 0.15 |
| Age group, n (%) | <.001 | |||
| <50 y | 4979 (6.0) | 3964 (6.0) | 1015 (6.1) | |
| 50–59 y | 11,059 (13.3) | 8707 (13.1) | 2352 (14.1) | |
| 60–69 y | 13,293 (16.0) | 10,267 (15.5) | 3026 (18.2) | |
| 70–79 y | 27,598 (33.3) | 22,725 (34.3) | 4873 (29.2) | |
| ≥80 y | 26,064 (31.4) | 20,660 (31.2) | 5404 (32.4) | |
| Women, n (%) | 21,323 (25.7) | 16,604 (25.0) | 4719 (28.3) | <.001 |
| Race, n (%)b | <.001 | |||
| Black | 5290 (6.4) | 3977 (6.0) | 1313 (7.9) | |
| White | 76,378 (92.0) | 61,306 (92.4) | 15,072 (90.4) | |
| Other | 1325 (1.6) | 1040 (1.6) | 285 (1.7) | |
| Married, n (%) | 49,767 (60.0) | 40,300 (60.8) | 9467 (56.8) | <.001 |
| VA copayment exemption, n (%) | 55,950 (67.4) | 44,006 (66.4) | 11,944 (71.6) | <.001 |
| Mean prior outpatient visits ±SDc | 13.7 ± 20.6 | 12.9 ± 19.6 | 16.8 ± 23.8 | <.001 |
| Comorbid conditions, n (%) | ||||
| Cancer | 11,291 (13.6) | 8753 (13.2) | 2538 (15.2) | <.001 |
| Cerebrovascular disease | 8913 (10.7) | 6756 (10.2) | 2157 (12.9) | <.001 |
| Chronic lung disease | 17,649 (21.3) | 13,461 (20.3) | 4188 (25.1) | <.001 |
| Diabetes mellitus | 24,518 (29.5) | 18,754 (28.3) | 5764 (34.6) | <.001 |
| Heart failure | 8561 (10.3) | 6477 (9.8) | 2084 (12.5) | <.001 |
| Hypertension | 63,469 (76.5) | 50,185 (75.7) | 13,284 (79.7) | <.001 |
| Myocardial infarction | 4233 (5.1) | 3292 (5.0) | 941 (5.6) | <.001 |
| Peripheral vascular disease | 9887 (11.9) | 7595 (11.5) | 2292 (13.7) | <.001 |
| eGFR, n (%) | <.001 | |||
| 45–59 ml/min per 1.73 m2 | 60,688 (73.1) | 48,747 (73.5) | 11,941 (71.6) | |
| 30–44 ml/min per 1.73 m2 | 18,542 (22.3) | 14,641 (22.1) | 3901 (23.4) | |
| 10–29 ml/min per 1.73 m2 | 3763 (4.5) | 2935 (4.4) | 828 (5.0) | |
| Year eGFR reporting began, n (%) | <.001 | |||
| 2005 | 28,521 (34.4) | 22,482 (33.9) | 6039 (36.2) | |
| 2006 | 23,262 (28.0) | 18,512 (27.9) | 4750 (28.5) | |
| 2007 | 12,631 (15.2) | 10,353 (15.6) | 2278 (13.7) | |
| 2008 | 18,501 (22.3) | 14,925 (22.5) | 3576 (21.5) | |
| 2009 | 78 (0.1) | 51 (0.1) | 27 (0.2) | |
eGFR, estimated GFR; VA, Veterans Affairs.
a
Statistical significance between the pre-reporting and post-reporting groups was measured with t tests for continuous variables and chi-square tests for dichotomous variables.
b
To identify patients with CKD detectable through laboratory testing (i.e., eGFR <60 ml/min per 1.73 m2), patients of unknown race (n=13,396 [16.1%]) were assigned to the category “white” for calculations of eGFR.
c
Prior outpatient visits were defined as the patient’s total number of VA outpatient visits during the 12 months before the creatinine index date.