Table 1. Demographics of acute lymphoblastic leukaemia study population by enrollment status.
| Characteristics | Total N=2569 | Enrolled (N=1408) | Not enrolled (N=1161) | Percent enrolled | P-valuea |
|---|---|---|---|---|---|
|
Demographic features | |||||
| Age at diagnosis | 0.501 | ||||
| 1–4 years | 1411 (54.9%) | 788 (56.0%) | 623 (53.7%) | 55.8 | |
| 5–9 years | 732 (28.5%) | 393 (27.9%) | 339 (29.2%) | 53.7 | |
| 10–14 years | 426 (16.6%) | 227 (16.1%) | 199 (17.1%) | 53.3 | |
| Male sex | 1451 (56.5%) | 810 (57.5%) | 641 (55.2%) | 55.8 | 0.238 |
| Race | <0.0001 | ||||
| White | 1752 (68.2%) | 1051 (74.6%) | 701 (60.4%) | 60.0 | |
| Asian | 306 (11.9%) | 132 (9.4%) | 174 (15.0%) | 43.1 | |
| Arab/West Asian | 48 (1.9%) | 24 (1.7%) | 24 (2.1%) | 50.0 | |
| Aboriginal | 73 (2.8%) | 39 (2.8%) | 34 (2.9%) | 53.4 | |
| Black | 54 (2.1%) | 28 (2.0%) | 26 (2.2%) | 51.9 | |
| Latin American | 37 (1.4%) | 17 (1.2%) | 20 (1.7%) | 45.9 | |
| Other | 52 (2.0%) | 25 (1.8%) | 27 (2.3%) | 48.1 | |
| Unknown | 247 (9.6%) | 92 (6.5%) | 155 (13.4%) | 37.2 | |
| Diagnostic era | |||||
| <2007 | 1280 (49.8%) | 712 (50.6%) | 568 (48.9%) | 55.6 | 0.429 |
| ⩾2007 | 1289 (50.2%) | 696 (49.4%) | 593 (51.1%) | 54.0 | |
|
Leukaemia features | |||||
| Initial white blood cell count | |||||
| <50 × 109 l-1 | 2115 (82.3%) | 1190 (84.5%) | 925 (79.7%) | 56.3 | 0.002 |
| ⩾50 × 109 l-1 | 454 (17.7%) | 218 (15.5%) | 236 (20.3%) | 48.0 | |
| CNS status | |||||
| CNS1 | 2292 (89.2%) | 1237 (87.9%) | 1055 (90.9%) | 54.0 | 0.002 |
| CNS2 | 217 (8.4%) | 142 (10.1%) | 75 (6.5%) | 65.4 | |
| CNS3 | 53 (2.1%) | 28 (2.0%) | 25 (2.2%) | 52.8 | |
| Unknown | 7 (0.3%) | 1 (0.1%) | 6 (0.5%) | 14.3 | |
| Immunophenotype | 0.0006 | ||||
| B-precursor | 1313 (51.1%) | 810 (57.5%) | 503 (43.3%) | 61.7 | |
| T | 159 (6.2%) | 75 (5.3%) | 84 (7.2%) | 47.2 | |
| Unknown | 1097 (42.7%) | 523 (37.1%) | 574 (49.4%) | 47.7 | |
| Cytogenetic risk group | 0.039 | ||||
| Favourable | 779 (30.3%) | 454 (32.2%) | 325 (28.0%) | 58.3 | |
| Standard | 1673 (65.1%) | 897 (63.7%) | 776 (66.8%) | 53.6 | |
| Unfavourable | 117 (4.6%) | 57 (4.0%) | 60 (5.2%) | 48.7 | |
|
Socioeconomic factors | |||||
| Median Km to nearest tertiary care centre (interquartile range) | 29.3 (12.7–104.5) | 30.1 (12.5–106.6) | 28.7 (13.3–99.3) | 0.689 | |
| Income quintile | 0.485 | ||||
| 1 (lowest) | 486 (18.9%) | 254 (18.0%) | 232 (20.0%) | 52.3 | |
| 2 | 479 (18.6%) | 259 (18.4%) | 220 (18.9%) | 54.1 | |
| 3 | 517 (20.1%) | 298 (21.2%) | 219 (18.9%) | 57.6 | |
| 4 | 537 (20.9%) | 292 (20.7%) | 245 (21.1%) | 54.4 | |
| 5 (highest) | 502 (19.5%) | 282 (20.0%) | 220 (18.9%) | 56.2 | |
| Missing | 48 | 23 | 25 | ||
a
P-value by Chi square test for categorical variables and by Wilcoxon rank sum test for continuous variable.