Table 2.
Frequency and Yield of Diagnostic Testing Obtained in the Initial Evaluation of CKD
| Test Obtained | No. (%)a | |||
|---|---|---|---|---|
| Frequency (N = 1487) | Abnormal Resultsb | Affected Diagnosisc | Affected Managementd | |
| Primarily for Diagnosis | ||||
| Urine | ||||
| Sediment | 1112 (74.8) | 104 (9.4) | 39 (3.5) | 37 (3.3) |
| Dipstick for protein | 1036 (69.7) | 356 (34.4) | 25 (2.4) | 23 (2.2) |
| Dipstick for blood | 1039 (69.9) | 159 (15.3) | 19 (1.8) | 22 (2.1) |
| SPEP | 1012 (68.1) | 84 (8.3) | 14 (1.4) | 17 (1.7) |
| Renal ultrasonography | 1007 (67.7) | 270 (26.8) | 59 (5.9) | 33 (3.3) |
| Urine microalbumin to creatinine ratio | 901 (60.6) | 494 (54.8) | 117 (13.0) | 120 (13.3) |
| Urine total protein to creatinine ratio | 811 (54.5) | 415 (54.8) | 114 (14.1) | 111 (13.7) |
| UPEP | 526 (35.4) | 23 (4.4) | 6 (1.1) | 8 (1.5) |
| ANA | 423 (28.5) | 218 (51.5) | 4 (0.9) | 5 (1.2) |
| Uric acid | 390 (26.2) | 172 (44.1) | 12 (3.3) | 38 (9.7) |
| Serum-free light chains | 374 (25.2) | 168 (44.9) | 5 (1.3) | 8 (2.2) |
| C3 | 360 (24.2) | 25 (6.9) | 5 (1.4) | 5 (1.4) |
| C4 | 359 (24.1) | 29 (8.1) | 4 (1.1) | 4 (1.1) |
| HBVe | 262 (17.6) | 1 (0.4) | 1 (0.4) | 1 (0.4) |
| HCV | 259 (17.4) | 3 (1.2) | 2 (0.8) | 2 (0.8) |
| ANCA | 205 (13.8) | 5 (2.4) | 0 | 0 |
| Hemoglobin A1c | 188 (12.6) | 72 (38.3) | 29 (15.4) | 19 (10.1) |
| Rheumatoid factor | 156 (10.5) | 19 (12.2) | 1 (0.6) | 3 (1.9) |
| DsDNA | 128 (8.6) | 9 (7.0) | 1 (0.8) | 2 (1.6) |
| Anti-Ro antibody | 77 (5.2) | 8 (10.4) | 2 (2.6) | 4 (5.2) |
| Anti-La antibody | 77 (5.2) | 5 (6.5) | 2 (2.6) | 4 (5.2) |
| Cryoglobulins | 74 (5.0) | 3 (4.1) | 4 (5.4) | 4 (5.4) |
| Kidney biopsy | 70 (4.7) | 70 (100) | 70 (100) | 70 (100) |
| Anti-GBM | 52 (3.6) | 0 | 0 | 0 |
| Abdominal CT | 33 (2.2) | 18 (55.5) | 11 (33.3) | 6 (18.2) |
| Creatine kinase | 30 (2.0) | 7 (23.3) | 1 (3.3) | 1 (3.3) |
| Renal nuclear scan | 24 (1.6) | 22 (91.7) | 16 (66.7) | 8 (33.3) |
| LDH | 19 (1.3) | 12 (63.2) | 1 (5.3) | 2 (10.5) |
| Haptoglobin | 15 (1.0) | 4 (26.7) | 1 (6.7) | 3 (20) |
| Antiphospholipid antibody | 12 (0.8) | 4 (33.3) | 1 (8.3) | 2 (16.7) |
| HIV | 6 (0.4) | 0 | 0 | 0 |
| Abdominal | ||||
| MRI | 4 (0.3) | 3 (75) | 0 | 0 |
| MRA | 4 (0.3) | 0 | 0 | 0 |
| Primarily for Management | ||||
| Calcium | 1410 (94.8) | 123 (8.7) | 5 (0.4) | 8 (0.6) |
| Hemoglobin | 1249 (84.0) | 373 (29.9) | 0 | 90 (7.2) |
| Phosphate | 1242 (83.5) | 214 (17.2) | 3 (0.2) | 19 (1.5) |
| Parathyroid hormone | 1102 (74.1) | 619 (56.2) | 0 | 97 (15.7) |
| 25-Hydroxyvitamin D | 817 (54.9) | 352 (43.1) | 0 | 119 (14.6) |
| Iron | 551 (37.1) | 52 (9.4) | 0 (0.2) | 84 (15.2) |
| LDL-C | 163 (11.0) | 65 (39.9) | 0 | 11 (6.7) |
Abbreviations: ANA, antinuclear antibody; ANCA, antineutrophil cytoplasmic antibody; Anti-GBM, antiglomerular basement membrane antibody; CKD, chronic kidney disease; CT, computed tomography; DsDNA, double-stranded DNA; HBV, hepatitis B virus; HCV, hepatitis C virus; HIV, human immunodeficiency virus; LDH, lactate dehydrogenase; LDL-C, low-density lipoprotein cholesterol; MRA, magnetic resonance angiogram; MRI, magnetic resonance imaging; SPEP, serum protein electrophoresis; UPEP, urine protein electrophoresis.
The denominator for the percentages provided is the number of tests ordered.
Defined for most laboratories based on the reference range established by the laboratory. For urine sediment, any finding other than an acellular sediment or epithelial cells was considered to be abnormal. For SPEP, UPEP, and serum-free light chains, any abnormal immunoglobulin finding was considered to be abnormal. For parathyroid hormone, Kidney Disease Outcomes Quality Initiative target plasma levels based on CKD stage were used to define abnormal laboratory values.2 An abnormal finding for imaging was defined as any abnormality documented in the final report, with the exception of simple cysts and nonobstructive stones for renal ultrasonography.
Defined as any test result that was noted in the nephrology progress notes to have contributed to, confirmed, or established any diagnosis.
Defined as any test result that were noted in the nephrology progress notes to have contributed to any management decision.
It is recommended that patients with advanced CKD (≥stage 4) receive hepatitis B vaccination before dialysis is initiated, and it is possible that some of these patients had hepatitis B serology tests performed for that reason; the serology tests were performed in 44 patients with CKD stage 4 and in 2 patients with CKD stage 5.