Table 1.
Patient Characteristics by Self-Reported Extent Bothered by Itchy Skin (All Data Extracted From Patient Questionnaires Completed at Enrollment)
| Overall | Self-Reported Extent Bothered by Itchy Skin |
|||||
|---|---|---|---|---|---|---|
| 1: Not At All Bothered | 2: Somewhat Bothered | 3: Moderately Bothered | 4: Very Much Bothered | 5: Extremely Bothered | ||
| Patients, N | 4,410 | 2,167 (49%) | 1,198 (27%) | 595 (13%) | 329 (7%) | 121 (3%) |
| Age at (y) | 69 [6-77] | 68 [6-76] | 70 [6-78] | 71 [6-78] | 70 [6-77] | 69 [6-77] |
| Female, n (%) | 1,812 (41%) | 868 (40%) | 487 (41%) | 254 (43%) | 136 (41%) | 67 (55%) |
| African American race, n (%) | 430 (10%) | 213 (10%) | 118 (10%) | 51 (9%) | 36 (11%) | 12 (10%) |
| eGFRa(mL/min/1.73 m2) | 29.0 [20.8-38.3] | 29.7 [21.3-38.9] | 28.8 [20.5-38.3] | 28.6 [20.8-36.5] | 28.1 [20.1-37.8] | 25.1 [19.5-33.2] |
| CKD duration at (y) | 4.85 [2.26-8.93] | 4.88 [2.21-9.32] | 4.98 [2.37-8.71] | 4.94 [2.31-9.93] | 4.05 [2.03-7.44] | 4.57 [2.37-8.23] |
| Reported cause of CKD, n (%) | ||||||
| Diabetes | 1,098 (26%) | 517 (25%) | 294 (25%) | 156 (27%) | 93 (29%) | 38 (34%) |
| Hypertension | 1,100 (26%) | 539 (26%) | 301 (26%) | 163 (28%) | 75 (23%) | 22 (20%) |
| GN | 580 (14%) | 312 (15%) | 140 (12%) | 70 (12%) | 42 (13%) | 16 (14%) |
| TIN | 428 (10%) | 225 (11%) | 112 (10%) | 50 (9%) | 30 (9%) | 11 (10%) |
| Polycystic | 208 (5%) | 106 (5%) | 68 (6%) | 25 (4%) | 4 (1%) | 5 (5%) |
| Other | 658 (15%) | 304 (14%) | 190 (16%) | 92 (16%) | 57 (18%) | 15 (14%) |
| Unknown | 193 (5%) | 97 (5%) | 48 (4%) | 22 (4%) | 22 (7%) | 4 (4%) |
| Comorbid conditions at baseline, n (%) | ||||||
| Coronary artery disease | 1,115 (26%) | 492 (23%) | 314 (27%) | 173 (30%) | 98 (30%) | 38 (32%) |
| Cerebrovascular disease | 463 (11%) | 222 (10%) | 120 (10%) | 65 (11%) | 39 (12%) | 17 (14%) |
| Congestive heart failure | 610 (14%) | 275 (13%) | 163 (14%) | 81 (14%) | 69 (21%) | 22 (18%) |
| Other cardiovascular disease | 1,047 (24%) | 504 (23%) | 282 (24%) | 137 (23%) | 91 (28%) | 33 (28%) |
| Peripheral vascular disease | 822 (19%) | 387 (18%) | 215 (18%) | 113 (19%) | 76 (23%) | 31 (26%) |
| Hypertension | 3,983 (91%) | 1,944 (91%) | 1,088 (92%) | 538 (92%) | 302 (92%) | 111 (93%) |
| Diabetes | 2,002 (45%) | 923 (43%) | 545 (45%) | 291 (49%) | 180 (55%) | 63 (52%) |
| Cancer (nonskin) | 827 (19%) | 402 (19%) | 226 (19%) | 124 (21%) | 61 (19%) | 14 (12%) |
| Gastrointestinal bleeding | 125 (3%) | 49 (2%) | 37 (3%) | 23 (4%) | 10 (3%) | 6 (5%) |
| Lung disease | 194 (11%) | 68 (8%) | 57 (11%) | 32 (12%) | 24 (18%) | 13 (20%) |
| Neurologic disease | 165 (4%) | 68 (3%) | 47 (4%) | 24 (4%) | 19 (6%) | 7 (6%) |
| Any psychiatric disorder | 491 (11%) | 202 (10%) | 129 (11%) | 83 (14%) | 50 (15%) | 27 (23%) |
| Recurrent cellulitis/gangrene | 76 (4%) | 23 (3%) | 25 (5%) | 10 (4%) | 14 (11%) | 4 (6%) |
| Cirrhosis of the liver | 53 (1%) | 21 (1%) | 11 (1%) | 9 (2%) | 10 (3%) | 2 (2%) |
| Laboratorya | ||||||
| Hemoglobin (g/dL) | 12.6 (1.8) | 12.7 (1.7) | 12.6 (1.8) | 12.4 (1.8) | 12.4 (1.9) | 12.2 (1.7) |
| Serum ferritin level (ng/mL) | 134 [73-247] | 134 [74-244] | 140 [75-245] | 132 [67-266] | 120 [68-223] | 141 [65-282] |
| Serum albumin level (g/dL) | 3.97 (0.50) | 3.98 (0.50) | 4.00 (0.47) | 3.93 (0.53) | 3.90 (0.53) | 3.83 (0.60) |
| Serum phosphorous level (mg/dL) | 3.71 (0.84) | 3.68 (0.85) | 3.70 (0.83) | 3.75 (0.80) | 3.81 (0.84) | 3.88 (0.80) |
| Total calcium (mg/dL) | 9.35 (0.58) | 9.36 (0.56) | 9.36 (0.56) | 9.33 (0.58) | 9.29 (0.69) | 9.30 (0.57) |
| Albuminuria or equivalentb | ||||||
| Normal | 1,030 (32%) | 547 (34%) | 269 (32%) | 121 (29%) | 70 (29%) | 23 (29%) |
| Mild | 919 (29%) | 458 (28%) | 252 (30%) | 108 (26%) | 76 (31%) | 25 (32%) |
| Severe | 1,262 (39%) | 619 (38%) | 329 (39%) | 186 (45%) | 97 (40%) | 31 (39%) |
| Glycated hemoglobinc, % | 7.2 (1.3) | 7.1 (1.3) | 7.3 (1.3) | 7.2 (1.2) | 7.2 (1.3) | 7.4 (1.6) |
| Patient-reported outcome | ||||||
| Dry skind | 1,474 (34%) | 353 (16%) | 341 (29%) | 405 (69%) | 266 (82%) | 109 (90%) |
Notes: Results are presented as mean (standard deviation), median [Q1-Q3], or N (%).
Abbreviations: ACR, albumin-to-creatinine ratio; AER, albumin excretion rate; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; GN, glomerulonephritis; TIN, tubulointerstitial nephritis; PCR, protein to creatinine ratio; PER, protein excretion rate.
Within 120 days from the first patient questionnaire with the completion of the pruritus survey question.
Normal: ACR < 30 mg/g or AER < 30 mg/24 h or PCR < 150 mg/g or PER < 150 mg/24 h or dipstick; Mild: 30 ≤ ACR < 300 mg/g or 30 ≤ AER < 300 mg/24 h or 150 ≤ PCR < 500 mg/g or 150 ≤ PER < 500 mg/24 h or dipstick trace to 1+; Severe: ACR ≥ 300 mg/g or AER ≥ 300 mg/24 h or PCR ≥ 500 mg/g or PER ≥ 500 mg/24 h or dipstick 1+ or greater.
Among patients with diabetes.
At least moderately bothered by dry skin.