Table 1.
Descriptive statistics for patient age and serum creatinine values measured by enzymatic and Jaffe methods.
| Variable: | Age | Female age | Men age | SCrEnzymatic (mg/dL) | SCrJaffe (mg/dL) |
|---|---|---|---|---|---|
| Number | 427 | 213 | 214 | 427 | 427 |
| Min | 42 | 42 | 42 | 0.66 | 0.66 |
| Max | 98 | 98 | 90 | 18.59 | 19.2 |
| Mean/Median | 67 | 66 | 66 | 1.78 | 1.79 |
| SD / IQR | 15 | 6.25 | 11.6 | 1.7 | 2.2 |
Fig. 1.
Comparison between enzymatic and Jaffe methods for serum creatinine (SCr) measurement. The upper part of the figure shows the analysis for all samples, while the lower part shows the analysis for samples with SCrENZ < 1.5 mg/dL. Bland-Altman plots are shown on the left, and Passing-Bablok regression plots on the right.
Table 2.
Multiple linear regression models for ΔeGFR by sex and eGFR equation (CKD-EPI, EKFC), with SCr (enzymatic, Jaffe) and age as predictors.
| Sex | Equation | Predictor | B | p |
|---|---|---|---|---|
| Male | ΔeGFRCKD-EPI | SCrEnz | −11.579 | <0.001 |
| SCrJaffe | 11.17 | <0.001 | ||
| Age | 0.005 | 0.756 | ||
| ΔeGFREKFC | SCrEnz | −11.042 | <0.001 | |
| SCrJaffe | 10.667 | <0.001 | ||
| Age | 0.004 | 0.783 | ||
| Female | ΔeGFRCKD-EPI | SCrEnz | −8.497 | <0.001 |
| SCrJaffe | 8.235 | <0.001 | ||
| Age | −0.018 | 0.153 | ||
| ΔeGFREKFC | SCrEnz | −7.684 | <0.001 | |
| SCrJaffe | 7.443 | <0.001 | ||
| Age | −0.019 | 0.097 |
Table 3.
Agreement in eGFR-based CKD staging between enzymatic and Jaffe methods using CKD-EPI and EKFC equations, assessed by weighted kappa and Kendall’s tau, stratified by sex.
| Equation | Male patients | Female patients | ||
|---|---|---|---|---|
| Weighted Kappa | Kendall’s Tau | Weighted Kappa | Kendall’s Tau | |
| CKD-EPI | 0.928 (CI: 0.900–0.956) | 0.949 | 0.923 (CI: 0.894–0.951) | 0.943 |
| EKFC | 0.916 (CI: 0.885–0.947) | 0.95 | 0.943 (CI: 0.918–0.969) | 0.959 |
Fig. 2.
Reclassification matrix of GFR categories in male (left side) and female (right side) patients using CKD-EPI (upper side) and EKFC (down) equations using enzymatic and Jaffe serum creatinine measurement.