Table 8.
Predictor variables selected and the associated R2 and Mallows’ Cp statistics for the RSQUARE selection method, and predictor variables selected by the stepwise selection method for predicting calcium oxalate relative supersaturation.
| Number of Variables | Selection method: RSQUARE | R 2 | Mallows’ Cp | Selection method: stepwise |
|---|---|---|---|---|
| 1 | Calcium | 0.762 | 642 | Calcium |
| 2 | Calcium, citrate | 0.799 | 511 | Calcium, citrate |
| 3 | Calcium, oxalate, citrate | 0.901 | 132 | Calcium, oxalate, citrate |
| 4 | Potassium, calcium, oxalate, citrate | 0.923 | 51.8 | Potassium, calcium, oxalate, citrate |
| 5 | Sodium, potassium, calcium, oxalate, citrate | 0.927 | 39.9 | Sodium, potassium, calcium, oxalate, citrate |
| 6 | Sodium, potassium, chloride, calcium, oxalate, citrate | 0.933 | 18.9 | Sodium, potassium, chloride, calcium, oxalate, citrate |
| 7 | Sodium, chloride, calcium, potassium, oxalate, citrate, sulfate | 0.936 | 11.7 | Sodium, potassium, chloride, calcium, oxalate, citrate, sulfate |
| 8 | pH, sodium, chloride, calcium, potassium, oxalate, citrate, sulfate | 0.937 | 7.9 | pH, sodium, chloride, calcium, potassium, oxalate, citrate, sulfate |