Table 1.
Characteristics of the Derivation and Validation Cohorts
| Cohort characteristics | Derivation cohort (n = 616) | Validation cohort (n = 285) |
|---|---|---|
| Age, mean (SD) (years) | 58 (15) | 58 (15) |
| Male sex, number (%) | 449 (72.9) | 205 (71.9) |
| Hemoglobin, mean (SD) (g/L) | 177 (11) | 177 (11) |
| Hematocrit, mean (SD) (L/L) | 0.53 (0.04) | 0.53 (0.04) |
| RBCs, mean (SD) (× 1012/L) | 6.11 (0.597) | 5.90 (0.607) |
| Platelets, mean (SD) (× 109/L) | 266 (162) | 281 (187) |
| Leukocytes, mean (SD) (× 109/L) | 9.2 (4.0) | 9.1 (3.3) |
| Neutrophils, mean (SD) (× 109/L) | 6.0 (3.7) | 5.7 (2.5) |
| JAK2 mutation positive, number (%) | 75 (12.2) | 31 (10.9) |
| Testing method, number (%) | ||
| Next-generation sequencing | 358 (58.1) | 173 (60.7) |
| Polymerase chain reaction | 155 (25.2) | 70 (24.6) |
| SNP allelotyping | 103 (16.7) | 42 (14.7) |
Abbreviations: SD, standard deviation; RBCs, red blood cells; JAK2, Janus Kinase 2; SNP, single nucleotide polymorphism. P-values for all variables were >0.05