Table 1.
Distribution of Neutropenia Risk Factors by Study Population
| Variables | No. | Derivation N=2500 | Validation N=1260 | P |
|---|---|---|---|---|
| % | % | |||
| Age, y | ||||
| ≥65 | 1445 | 38.4 | 38.6 | .464 |
| Prior chemotherapy | 880 | 24.4 | 21.6 | .029 |
| Baseline labs | ||||
| AST>35 U/L | 479 | 13.5 | 12.5 | .211 |
| AP>120 U/L | 715 | 19.5 | 19.7 | .456 |
| Bilirubin>1 mg/dL | 153 | 4.1 | 4.4 | .353 |
| GFR<60 mL/min | 732 | 19.5 | 19.4 | .508 |
| WBC<5000/mm3 | 499 | 12.8 | 14.3 | .106 |
| Cancer type | ||||
| Colorectum | 521 | 14.0 | 13.7 | |
| Small cell lung | 210 | 5.8 | 5.2 | |
| Nonsmall cell lung | 697 | 19.0 | 17.5 | .714 |
| Ovary | 312 | 8.4 | 8.1 | |
| Breast | 1473 | 38.7 | 40.1 | |
| Lymphoma | 547 | 14.1 | 15.4 | |
| Medications | ||||
| Immunosuppressives | 534 | 14.4 | 13.7 | .296 |
| Planned RDI | ||||
| ≥85% | 2623 | 69.9 | 69.4 | |
| <85% | 880 | 23.2 | 23.9 | .862 |
| Chemotherapy | ||||
| Anthracyclines | 1469 | 37.8 | 41.5 | .016 |
| Platinum(s) | 1200 | 32.5 | 30.8 | .156 |
| Taxanes | 1083 | 29.0 | 28.3 | .340 |
| Alkylating agents | 1615 | 42.1 | 44.6 | .078 |
| Topoisomerase II inhibitors | 232 | 6.2 | 6.0 | .432 |
| Gemcitabine | 257 | 6.9 | 6.7 | .415 |
| Topoisomerase I inhibitors | 41 | 1.1 | 1.01 | .476 |
| Vinorelbine | 120 | 3.4 | 2.8 | .178 |
| Primary CSF prophylaxis | 779 | 19.6 | 22.9 | .012 |
RDI indicates relative dose intensity; GFR, glomerular filtration rate; AST, aspartate aminotransferase; SN, severe neutropenia; FN, febrile neutropenia; WBC, white blood count; AP, alkaline phosphatase; CSF, colony-stimulating factors.