Table 1.
Definition of Covariates
| COVARIATE | DEFINITION | SOURCE |
|---|---|---|
|
| ||
| Demographic | ||
|
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| Age | Categorized as: 16–45; 46–60; 61–75; >75 yrs. | USRDS |
|
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| Sex | Male or female | USRDS |
|
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| Race | White, Black, Other | USRDS |
|
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| Medicaid Eligibility | Indicator for dual eligibility during any part of the baseline | USRDS |
|
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| Year of treatment | 2004, 2005, 2006, 2007, 2008 | Clinical Database |
|
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| Census Region | Based on location of last dialysis center in baseline period: Northeast, South, Midwest, West | USRDS |
|
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| Clinical | ||
|
| ||
| Vintage | Categorized as 0; 1–3; 4 or more yrs. | USRDS |
|
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| ESRD Reason | Diabetes, Glomerulonephritis, hypertension, other | USRDS |
|
| ||
| BMI | Categorized as underweight, normal, overweight, obese | Clinical Database & USRDS |
|
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| Anemia Management | ||
|
| ||
| Access | Most recent vascular access (catheter vs fistula/graft) prior to TSAT index date | Clinical Database |
|
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| EPO dose (baseline) | Total EPO dose, (quintiles) | Clinical Database |
|
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| EPO dose (exposure) | Total EPO dose, (tertiles plus a no-use category) | Clinical Database |
|
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| Index TSAT | Last TSAT at baseline (quintiles) | Clinical Database |
|
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| Iron dose | Total dose at last month of baseline, categorized as none, low (1–200 mg), or high (>200mg) | Clinical Database |
|
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| Hemoglobin | Most proximal Hb lab prior to index TSAT date (<10,10–11,>11–12,>12–13,>13) | Clinical Database |
|
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| Ferritin | Most proximal serum ferritin prior to index TSAT date (quintiles) | Clinical Database |
|
| ||
| Albumin | At baseline (<3.3, 3.3–3.9, >3.9) | Clinical Database |
|
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| Comorbidities | ||
|
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| Hospital days in last month of baseline | Categorized as 0, 1–3, <=4 | USRDS, Medicare Part A Claims |
|
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| Infection in last month | Any hospital admission in the last month with one of the following ICD-9-CM diagnostic codes as the principal diagnostic code: 001–139, 254.1, 320–326, 331.81, 372– 372.39, 373.0–373.2, 382–382.4, 383.0, 386.33, 386.35, 388.60, 390–393, 421–421.1, 422.0, 422.91–422.93, 460–466, 472–474.0, 475–476.1, 478.21–478.24, 478.29, 480–490, 491.1, 494, 510–511, 513.0, 518.6, 519.01, 522.5, 522.7, 527.3, 528.3, 540–542, 566–567.9, 569.5, 572–572.1, 573.1– 573.3, 575–575.12, 590–590.9, 595–595.4, 597–597.89, 598, 599.0, 601–601.9, 604–604.9, 607.1, 607.2, 608.0, 608.4, 611.0, 614–616.1, 616.3–616.4, 616.8, 670, 680–686.9, 706.0, 711–711.9, 730–730.3, 730.8–730.9, 790.7–790.8, 996.60– 996.69, 997.62, 998.5, and 999.3. | USRDS, Medicare Part A Claims |
| Any claims with the following HCPCS codes for antibiotic use in last month of baseline: J3370, J0690, J0713, J0692, J0696, J1580, J3260, J0278, J1840, J1956. | USRDS, Medicare Part A & B Claims | |
| Any indication of IV antibiotic use in the last month of baseline. | Clinical Database | |
|
| ||
| Pneumonia | Any ICD-9-CM diagnostic code of 481.xx – 486.xx in baseline period | USRDS, Medicare Part A & B Claims |
|
| ||
| Vascular Access Infection | Any ICD-9-CM diagnostic code of 996.62 in baseline period | |
|
| ||
| Sepsis | Any ICD diagnostic code 038.xx, 995.90, 995.91, 995.92 in baseline period | |
|
| ||
| Diabetes | Any ICD-9-CM diagnostic code of 250.xx in baseline period | |
|
| ||
| Ischemic Stroke | Any ICD-9-CM diagnostic code of 434.01, 434.11, 434.91, 435, 436, 437, 438, V12.54 in baseline period | |
|
| ||
| MI | Any ICD-9-CM diagnostic code of 410.xx in baseline period | |
|
| ||
| COPD | Any ICD-9-CM diagnostic code of 490.xx-496.xx, 505.xx, 506.4 in baseline period | |
|
| ||
| Cancer | Any ICD-9-CM diagnostic code of 173.3, 173.9, 174.0–175.9, 179–195, 196–199, 232.9, 233.0, 233.1, 300.29, 338.3, 789.51, 795.82, 799.4, V67.2, 200, 201, 202.0–202.3, 202.50- 203.01,203.8, 238.6, 273.3 in baseline period | |
|
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| GI bleeding | Any ICD-9-CM diagnostic code of 578.xx in baseline period | |
|
| ||
| Additional Comorbidities for Sensitivity Analyses | ||
|
| ||
| Pulmonary circulation disease | Any ICD-9-CM diagnostic code of 415.xx-417.xx in baseline period | USRDS, Medicare Part A & B Claims |
|
| ||
| Peptic Ulcer Disease | Any ICD-9-CM diagnostic code of 530.2, 531.xx-534.xx, V12.71 in baseline period | |
|
| ||
| Liver disease | Any ICD-9-CM diagnostic code of 070.32, 070.33, 070.54, 456.0, 456.1, 456.20, 456.21, 571.0, 571.2, 571.3, 571.4, 571.5, 571.6, 571.8, 571.9, 572.3, 572.8, V42.7 in baseline period | |
|
| ||
| Other neurological problem | Any ICD-9-CM diagnostic code 331.9, 332.0, 333.4, 333.5, 334–335, 340, 341, 345.0, 345.1, 345.4, 345.5, 345.8, 345.9, 348.1, 348.3, 780.3, 784.3 in baseline period | |
|
| ||
| Substance abuse | Any ICD-9-CM diagnostic code 303.xx-305.xx in baseline period | |
|
| ||
| Ischemic Heart disease, other heart disease, peripheral vascular disease, history of CABG, Stent, PTCA | Any ICD-9-CM diagnostic code of 411.xx-414.xx, 420.xx- 429.xx, 785.o, V45.0, v53.3, 402.11, 402.91, 404.11, 404.12, 404.91, 404.93, 093.2, 746.3–746.6, v42.2, v43.3, v43.4441.xx- 443.xx, 447.1, 557.1, 557.9, 444.xx-445.xx; Procedure codes of 00.66, 92982, 92985, 36.06, 36.07, 92980, 33510–33519 in baseline period | |
|
| ||
| Hypertension | Any ICD-9-CM diagnostic code of 401.xx-405.xx, except 402.11, 402.91, 404.11, 404.13, 404.91, 404.93 in baseline period | |
|
| ||
| Rheumatic heart disease | Any ICD-9-CM diagnostic code of 393.xx -398.xx in baseline period | |
|
| ||
| Psychiatric problems | Any ICD-9-CM diagnostic code 295.xx-298.xx in baseline period | |
|
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| Autoimmune disorders | Any ICD-9-CM diagnostic code of 564.1, 696.0, 696.1, 695.4, 710.0, 701.0, 710, 714, 720, 725 in baseline period | |
|
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| Blood loss anemia | Any ICD-9-CM diagnostic code of 280.0 in baseline period | |
|
| ||
| Transfusion | Indicator for receipt of one or more transfusions during the baseline period, based on HCPCS codes P9010, P9011, P9016, P9021, P9022, P9038, P9039, P9040, 36430 and ICD- 9 codes 99.03, 99.04 | |