Table 3.
Hemoglobin (g/dl) versus GFR (ml/min per 1.73 m2) and covariates in a threshold regression model
| Parameter | Parameter Estimates (95% CI)
|
||
|---|---|---|---|
| Unadjusted(n = 340) | Age/Gender Adjusted(n = 340) | Fully Adjusted(n = 339) | |
| GFR threshold, c (ml/min per 1.73 m2) | 43 (28 to 52) | 43 (29 to 51) | 43 (NA)a |
| Y-intercept, mean hemoglobin at GFR threshold, c (g/dl) | 12.6 (12.3 to 12.9) | 12.6 (12.3 to 13.0) | 12.7 (12.5 to 13.1) |
| Parameter | |||
| GFR ≤c, per 5-ml/min per 1.73 m2 decrease | −0.3 (−0.5 to −0.2) | −0.4 (−0.5 to −0.2) | −0.3 (−0.5 to −0.2) |
| GFR >c, per 5-ml/min per 1.73 m2 decrease | −0.1 (−0.2 to 0.0) | −0.1 (−0.2 to 0.0) | −0.1 (−0.2 to 0.0) |
| Female gender | −0.1 (−0.5 to 0.2) | 0.0 (−0.4 to 0.3) | |
| Age, per 5-yr increase | 0.1 (−0.1 to 0.3) | 0.2 (0.0 to 0.4) | |
| Black versus nonblack race | −0.1 (−0.6 to 0.3) | ||
| Glomerular versus nonglomerular CKD | −0.9 (−1.3 to −0.5) | ||
a
95% CI was not attainable (NA): The lower bound was less than a GFR of 20 ml/min per 1.73 m2, and the upper bound was >60 ml/min per 1.73 m2, the bounds of the search for threshold, c, using profile likelihood.