Article Figures & Data
Figures
Figure 1. Unadjusted, case mix–adjusted, and multivariable-adjusted relative risks (RR; of death) and 95% confidence intervals (CI) for eight categories of serum phosphorus (referent range, 4.0 to 5.0 mg/dl). For all analyses, case mix adjustment refers to adjustment for age, gender, race or ethnicity, diabetes, and vintage. Multivariable adjustment refers to case mix plus body weight, URR*, serum albumin, creatinine, predialysis BUN*, bicarbonate*, cholesterol, hemoglobin, ferritin*, and aluminum. Phosphorus models simultaneously adjusted for calcium + parathyroid hormone (PTH), calcium models simultaneously adjusted for phosphorus + PTH, PTH models simultaneously adjusted for phosphorus + calcium. *Inclusion of linear and quadratic terms. Categories of vintage <2 yr (referent), 2 to 5 yr, ≥5 yr, and missing. Categories of cholesterol <120, 120 to 160, 160 to 200 (referent), 200 to 240, ≥240 mg/dl, and missing. Companion models substituting body surface area, Quetèlet’s index, or calculated total body water for body weight, and Kt/V or Kt for URR did not change parameter estimates for phosphorus, calcium, or PTH.
Figure 2. Unadjusted, case mix–adjusted, and multivariable-adjusted RR (of death) and 95% CI for eight categories of measured serum calcium (referent range, 9.0 to 9.5 mg/dl).
Figure 3. Unadjusted, case mix–adjusted, and multivariable-adjusted RR (of death) and 95% CI for eight categories of adjusted serum calcium (measured calcium adjusted for serum albumin, referent range, 9.0 to 9.5 mg/dl).
Figure 4. Unadjusted, case mix–adjusted, and multivariable-adjusted RR (of death) and 95% CI for 12 categories of calcium × phosphorus product (referent range, 40 to 45 mg2/dl2).
Figure 5. Unadjusted, case mix–adjusted, and multivariable-adjusted RR (of death) and 95% CI for four categories of intact parathyroid hormone (referent range, 150 to 300 pg/ml).
Tables
Table 1. Patient characteristics by serum phosphorus categorya
<3 mg/dl (n = 895) 3–4 mg/dl (n = 3860) 4–5 mg/dl (n = 8723) 5–6 mg/dl (n = 10,421) 6–7 mg/dl (n = 8367) 7–8 mg/dl (n = 4547) 8–9 mg/dl (n = 2219) ≥9 mg/dl (n = 1506) P Value a Values are means; medians presented for vintage and ferritin. P values for proportions and means are age-adjusted. BUN, blood urea nitrogen; URR, urea reduction ratio. Age (years) 67.3 66.4 64.6 61.9 58.6 55.3 52.1 48.7 <0.0001 Gender (% female) 53% 48% 50% 50% 48% 48% 46% 42% <0.0001 Race/ethnicity (%) <0.0001 white 27% 37% 39% 39% 35% 35% 37% 44% black 56% 45% 42% 41% 44% 44% 43% 36% Hispanic 14% 15% 15% 16% 17% 18% 17% 16% other 3% 3% 4% 3% 4% 4% 4% 3% Diabetes (%) 46% 48% 50% 49% 46% 43% 40% 35% <0.0001 Vintage (years) 1.50 1.46 1.51 1.59 1.82 1.95 2.12 2.07 <0.0001 Weight (kg) 65.5 68.8 70.6 72.1 73.9 74.9 75.3 74.8 <0.0001 Quetèlet’s (body mass) index (kg/m2) 25.1 25.7 26.2 26.7 27.2 27.4 27.8 27.0 <0.0001 Bicarbonate (mEq/L) 23.3 22.6 21.9 21.2 20.6 19.9 19.2 18.1 <0.0001 BUN (mg/dl) 47 51 55 58 62 65 68 72 <0.0001 Creatinine (mg/dl) 7.7 8.0 8.5 9.3 10.3 11.0 11.6 12.2 <0.0001 Albumin (g/dl) 3.60 3.74 3.82 3.86 3.90 3.91 3.92 3.93 <0.0001 Cholesterol (mg/dl) 163 170 172 173 172 170 167 165 0.05 Hemoglobin (g/dl) 10.1 10.3 10.5 10.5 10.5 10.4 10.4 10.3 0.002 Ferritin (μg/L) 476 433 431 411 418 408 383 342 <0.0001 URR (%) 69.8% 69.5% 69.4% 68.9% 68.4% 67.7% 67.1% 65.9% <0.0001 Table 2. Patient characteristics by serum calcium categorya
<8.0 mg/dl (n = 2325) 8.0–8.5 mg/dl (n = 4594) 8.5–9.0 mg/dl (n = 10,451) 9.0–9.5 mg/dl (n = 10,759) 9.5–10.0 mg/dl (n = 6712) 10.0–10.5 mg/dl (n = 3652) 10.5–11.0 mg/dl (n = 1478) ≥11.0 mg/dl (n = 567) P Value a Values are means, medians presented for vintage and ferritin. P values for proportions and means are age-adjusted. Age (years) 52.3 58.4 60.5 61.6 62.1 61.9 61.2 62.3 <0.0001 Gender (% female) 39% 41% 46% 50% 53% 56% 54% 60% <0.0001 Race/ethnicity (%) <0.0001 white 23% 31% 37% 40% 40% 43% 41% 41% black 53% 44% 43% 42% 42% 40% 41% 37% Hispanic 20% 21% 17% 15% 13% 13% 13% 18% other 4% 4% 3% 3% 4% 4% 5% 4% Diabetes (%) 39% 49% 50% 48% 44% 41% 38% 40% <0.0001 Vintage (years) 2.5 1.9 2.0 2.4 2.5 2.5 2.5 2.5 <0.0001 Weight (kg) 75.4 73.5 72.5 72.4 71.6 70.5 69.6 69.9 <0.0001 Quetèlet’s (body mass) index (kg/m2) 27.3 26.9 26.7 26.8 26.5 26.1 25.9 25.9 <0.0001 Bicarbonate (mEq/L) 19.0 20.0 20.7 21.2 21.6 21.9 22.4 22.5 <0.0001 BUN (mg/dl) 66 61 59 58 59 58 57 55 <0.0001 Creatinine (mg/dl) 11.4 9.9 9.3 9.3 9.7 9.7 9.8 9.1 <0.0001 Albumin (g/dl) 3.96 3.92 3.86 3.83 3.84 3.84 3.79 3.66 <0.0001 Cholesterol (mg/dl) 165 169 171 172 172 172 170 171 <0.0001 Hemoglobin (g/dl) 10.3 10.4 10.4 10.5 10.5 10.5 10.5 10.3 <0.0001 Ferritin (μg/L) 349 367 415 415 445 455 484 488 <0.0001 URR (%) 66.2% 67.5% 68.2% 68.9% 69.6% 69.8% 69.6% 70.0% <0.0001 Table 3. Twenty most common primary ICD-9-CM codesa
Diagnosis Code Description N % of First Hospitalizations a ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification. 996.1 Mechanical complication of other (noncardiac) vascular device, implant, and graft 2423 9.8% 585 Chronic renal failure 2132 8.6% 996.70, 73, and 74 Other complications of internal prosthetic device, implant, and graft 1401 5.6% 480–486 Pneumonia 1086 4.4% 276.6 Fluid overload 824 3.3% 428 Congestive heart failure 815 3.3% 786.5 Chest pain 752 3.0% 038.9 Unspecified septicemia 630 2.5% 578 Gastrointestinal hemorrhage 356 1.4% 999.9 Other and unspecified complications of medical care 271 1.1% 681–682 Cellulitis and abscess 258 1.0% 443 Peripheral vascular disease 239 1.0% 427.5 Cardiac arrest 231 0.9% 996.62 Infection and inflammatory reaction as a result of other (noncardiac) vascular device, implant, and graft 228 0.9% 787.01 Nausea with vomiting 205 0.8% 410 Acute myocardial infarction 198 0.8% 413 Angina pectoris 171 0.7% 780.6 Fever 156 0.6% 785.4 Gangrene 128 0.5% 251.2 Hypoglycemia 103 0.4%