Table 1.
Baseline characteristics by World Bank income group
| Overall (n=1500) | Low-income or lower-middle-income country (n=318) | Upper-middle-income country (n=824) | High-income country (n=358) | p value | ||
|---|---|---|---|---|---|---|
| WHO Region | ||||||
| African Region | 41 (2·7%) | 8 (2·5%) | 33 (4·0%) | 0 | .. | |
| Region of the Americas | 847 (56·5%) | 11 (3·5%) | 675 (81·9%) | 161 (45·0%) | .. | |
| Eastern Mediterranean | 211 (14·1%) | 211 (66·4%) | 0 | 0 | .. | |
| European Region | 322 (21·5%) | 10 (3·1%) | 115 (14·0%) | 197 (55·0%) | .. | |
| South-East Asian Region | 63 (4·2%) | 63 (19·8%) | 0 | 0 | .. | |
| Western Pacific Region | 16 (1·1%) | 15 (4·7%) | 1 (0·1%) | 0 | .. | |
| Age, years | 0·041 | |||||
| Median | 8 (4–13) | 8 (4–13) | 7 (4–12) | 9 (4–14) | ||
| Age, years (category) | 0·022 | |||||
| <1 | 42 (2·8%) | 6 (1·9%) | 24 (2·9%) | 12 (3·4%) | .. | |
| 1–9 | 823 (54·9%) | 181 (56·9%) | 471 (57·2%) | 171 (47·8%) | .. | |
| 10–14 | 385 (25·7%) | 69 (21·7%) | 207 (25·1%) | 109 (30·4%) | .. | |
| 15–18 | 250 (16·7%) | 62 (19·5%) | 122 (14·8%) | 66 (18·4%) | .. | |
| Sex | 0·17 | |||||
| Male | 891 (59·4%) | 199 (62·6%) | 494 (60·0%) | 198 (55·3%) | .. | |
| Female | 607 (40·5%) | 119 (37·4%) | 330 (40·0%) | 158 (44·1%) | .. | |
| Other | 2 (0·1%) | 0 | 0 | 2 (0·6%) | .. | |
| Cancer type | <0·0001 | |||||
| Acute lymphoblastic leukaemia or acute lymphoblastic lymphoma | 737 (49·1%) | 164 (51·6%) | 413 (50·1%) | 160 (44·7%) | .. | |
| Other haematological malignancies | 266 (17·7%) | 75 (23·6%) | 141 (17·1%) | 50 (14·0%) | .. | |
| Solid tumours | 363 (24·2%) | 68 (21·4%) | 204 (24·8%) | 91 (25·4%) | .. | |
| CNS tumours | 126 (8·4%) | 11 (3·5%) | 64 (7·8%) | 51 (14·2%) | .. | |
| Post-haematopoietic stem-cell transplantation, non-malignancy | 8 (0·5%) | 0 | 2 (0·2%) | 6 (1·7%) | .. | |
| Treatment type | <0·0001 | |||||
| Cancer-directed therapy | 1243 (82·9%) | 258 (81·1%) | 719 (87·3%) | 266 (74·3%) | .. | |
| Palliative therapy | 53 (3·5%) | 14 (4·4%) | 32 (3·9%) | 7 (2·0%) | .. | |
| Treatment completed | 127 (8·5%) | 17 (5·3%) | 53 (6·4%) | 57 (15·9%) | .. | |
| No active treatment | 69 (4·6%) | 28 (8·8%) | 13 (1·6%) | 28 (7·8%) | .. | |
| Unknown | 8 (0·5%) | 1 (0·3%) | 7 (0·8%) | 0 | .. | |
| Time since last chemotherapy, days | 0·58 | |||||
| ≤30 | 1171/1203 (97·3%) | 246/255 (96·5%) | 690/708 (97·5%) | 235/240 (97·9%) | .. | |
| >30 | 32/1203 (2·7%) | 9/255 (3·5%) | 18/708 (2·5%) | 5/240 (2·1%) | .. | |
| Received haematopoietic stem-cell transplantation | <0·0001 | |||||
| Yes | 81 (5·4%) | 9 (2·8%) | 31 (3·8%) | 41 (11·5%) | .. | |
| No | 1414 (94·3%) | 309 (97·2%) | 789 (95·8%) | 316 (88·3%) | .. | |
| Unknown | 5 (0·3%) | 0 | 4 (0·5%) | 1 (0·3%) | .. | |
| Time since transplantation, days | 0·51 | |||||
| <30 | 6/81 (7·4%) | 0 | 4/31 (12·9%) | 2/41 (4·9%) | .. | |
| 31–99 | 13/81 (16·0%) | 1/9 (11·1%) | 4/31 (12·9%) | 8/41 (19·5%) | .. | |
| 100–300 | 20/81 (24·7%) | 1/9 (11·1%) | 9/31 (29·0%) | 10/41 (24·4%) | .. | |
| >300 | 31/81 (38·3%) | 6/9 (66·7%) | 9/31 (29·0%) | 16/41 (39·0%) | .. | |
| Unknown or missing* | 11/81 (13·6%) | 1/9 (11·1%) | 5/31 (16·1%) | 5/41 (12·2%) | .. | |
| Received radiotherapy | <0·0001 | |||||
| Yes | 156/1453 (10·7%) | 25/279 (9·0%) | 73/819 (8·9%) | 58/355 (16·3%) | .. | |
| No | 1249/1453 (86·0%) | 253/279 (90·7%) | 730/819 (89·1%) | 266/355 (74·9%) | .. | |
| Unknown | 48/1453 (3·3%) | 1/279 (0·4%) | 16/819 (2·0%) | 31/355 (8·7%) | .. | |
| Absolute neutrophil count, cells per mm3 | <0·0001 | |||||
| ≤500 | 375/1212 (30·9%) | 109/243 (44·9%) | 202/716 (28·2%) | 64/253 (25·3%) | .. | |
| >500 | 837/1212 (69·1%) | 134/243 (55·1%) | 514/716 (71·8%) | 189/253 (74·7%) | .. | |
| Absolute lymphocyte count, cells per mm3 | <0·0001 | |||||
| ≤300 | 273/1188 (23·0%) | 82/237 (34·6%) | 128/702 (18·2%) | 63/249 (25·3%) | .. | |
| >300 | 915/1188 (77·0%) | 155/237 (65·4%) | 574/702 (81·8%) | 186/249 (74·7%) | .. | |
| Comorbidities† | 0·71 | |||||
| At least one comorbidity | 256 (17·1%) | 51 (16·0%) | 150 (18·2%) | 55 (15·4%) | .. | |
| None | 1173 (78·2%) | 259 (81·4%) | 659 (80·0%) | 255 (71·2%) | .. | |
| Unknown | 71 (4·7%) | 8 (2·5%) | 15 (1·8%) | 48 (13·4%) | .. | |
| Intensive treatment | <0·0001 | |||||
| Yes | 478 (31·9%) | 104 (32·7%) | 301 (36·5%) | 73 (20·4%) | .. | |
| No | 1022 (68·1%) | 214 (67·3%) | 523 (63·5%) | 285 (79·6%) | .. | |
p values were calculated using the χ2 test, Fisher's exact test, or the Kruskal-Wallis test.
*
Missing refers to patients who did not answer the question regarding time since transplantation.
†
Comorbidities included history of high-dose steroid within 14 days before diagnosis or illness, pre-existing pulmonary disease, pre-existing cardiac insufficiency, and a free text option for other conditions (eg, obesity, graft-versus-host disease, trisomy 21, pre-existing renal disease, among others).