Table 2.
Odds of ESA-responsiveness for anemia management in 38,393 long-term HD patients, represented by the odds ratio (OR) [and 95% confidence interval (CI)] of the highest vs. lowest quartile of ESA-responsiveness coefficient as shown in Table 1.
| Variable | Unadjusted OR (95% CI) | Case-Mix adjusted OR (95% CI) |
|---|---|---|
| Age (each 10 year increase) | 1.11 (1.09–1.13) | 1.06 (1.06–1.11) |
| Women (vs. men) | 0.90 (0.85–0.95) | 0.78 (0.73–0.83) |
| Diabetics (vs. non-diabetics) | 1.08 (1.02–1.14) | 1.04 (0.98–1.11) |
| African Americans (vs. non-Hispanic Whites) | 0.73 (0.68–0.78) | 0.87 (0.81–0.94) |
| Hispanics (vs. non-Hispanic Whites) | 1.25 (1.14–1.37) | 1.30 (1.17–1.43) |
| Dialysis vintage >5 yrs (vs. 3–6 mo) | 1.48 (1.34–1.64) | 1.44 (1.29–1.60) |
| Primary insurance: Medicaid (vs. Medicare) | 0.70 (0.62–0.80) | 0.76 (0.66–0.87) |
| Dialysis catheter (vs. arteriovenous graft or fistula) | 0.68 (0.63–0.73) | 0.81 (0.75–0.88) |
| Pre-existing comorbid states: | ||
| AIDS | 0.91 (0.67–1.22) | 1.80 (1.07–3.03) |
| HIV | 0.64 (0.50–0.84) | 0.51 (0.32–0.80) |
| Cancer | 0.77 (0.65–0.91) | 0.70 (0.59–0.83) |
| Congestive heart failure | 0.90 (0.84–0.97) | 0.87 (0.81–0.94) |
| Dysrhythmia | 0.93 (0.78–1.10) | 0.91 (0.76–1.09) |
| Ischemic heart disease | 1.06 (0.98–1.15) | 0.98 (0.89–1.08) |
| Unable to ambulate | 0.69 (0.56–0.85) | 0.77 (0.62–0.96) |
| Smoker status (vs. never smoked) | 0.92 (0.80–1.06) | 1.01 (0.87–1.17) |
| Body mass index (each kg/m2 increase) | 0.98 (0.97–0.98) | 0.99 (0.98–0.99) |
| Residual renal function (each Kru unit increase) | 1.14 (1.10–1.19) | 1.04 (1.01–1.07) |
| Kt/V single pool (each 0.1 unit increase) | 1.12 (1.11–1.13) | 1.11 (1.10–1.12) |
| nPCR or nPNA (each g/kg/day increase) | 1.58 (1.40–1.78) | 1.25 (1.10–1.42) |
| Serum albumin (each 0.2 g/dL increase)* | 1.31 (1.29–1.33) | 1.31 (1.29–1.34) |
| creatinine (each 1 mg/dL increase) * | 1.01 (1.00–1.02) | 1.06 (1.05–1.07) |
| TIBC (each 10 mg/dL increase) * | 1.07 (1.06–1.07) | 1.07 (1.06–1.08) |
| iron (each 10 ng/ml increase) * | 1.22 (1.21–1.24) | 1.20 (1.19–1.22) |
| ISAT (each 10% increase) * | 1.39 (1.36–1.43) | 1.36 (1.32–1.40) |
| ferritin (each 100 ng/mL increase) * | 1.02 (1.02–1.03) | 1.02 (1.01–1.02) |
| phosphorus (each mg/dL increase) * | 0.89 (0.87–0.90) | 0.92 (0.90–0.94) |
| calcium (each mg/dL increase) * | 1.25 (1.21–1.30) | 1.27 (1.22–1.32) |
| intact PTH (each 100 pg/mL increase) * | 0.94 (0.93–0.95) | 0.95 (0.94–0.96) |
| alkaline phosphatase (each 10 U/L increase) * | 0.97 (0.96–0.98) | 0.97 (0.95–0.98) |
| Blood WBC (each 103/μl increase) * | 1.00 (0.99–1.01) | 0.99 (0.98–1.01) |
| lymphocytes (each % increase) * | 1.04 (1.04–1.05) | 1.05 (1.05–1.06) |
| IV iron had to be administered * | 0.84 (0.83–0.86) | 0.86 (0.85–0.88) |
OR values in bold are statistically significant. OR<1.0 suggests worse ESA-hyporesponsiveness, whereas OR>1 indicates greater responsiveness to ESA treatment. ESA responsiveness was extracted based on the repeated measure model: Hemoglobinij = βlongitudinal * ESAij + ci [EF4](see Appendix).
All case-mix adjusted models include age, sex, race and ethnicity, diabetes mellitus and 11 pre-existing comorbid states, history of tobacco smoking, dialysis vintage, primary insurance, marital status, standardized mortality ratio, dialysis dose, dialysis catheter, and residual renal function. Each case-mix model that examines a laboratory variable or IV iron as the predictor includes only this variable as the predictor while adjusting for the above-mentioned covariates.
Abbreviations: ISAT: iron saturation ratio, TIBC: Total iron binding capacity, nPCR: normalized protein catabolic rate, nPNA: normalized protein nitrogen appearance, WBC: White blood cell count, ESA: erythropoiesis stimulating agent, PTH: parathyroid hormone