Table 1.
Baseline variables of study cohort
| Variable | Total n = 14,056 |
Canadian long-term resident n = 12,250 |
Immigrant n = 1806 |
p-value | |
|---|---|---|---|---|---|
| Age at diagnosis | Mean (SD) | 60.08 (12.99) | 61.12 (12.85) | 53.01 (11.68) | < 0.01 |
| Neighborhood Income Quintile | 1–n (%) | 2291 (16.3%) | 1890 (15.4%) | 401 (22.2%) | < 0.01 |
| 2 | 2575 (18.3%) | 2242 (18.3%) | 333 (18.4%) | ||
| 3 | 2641 (18.8%) | 2279 (18.6%) | 362 (20.0%) | ||
| 4 | 3090 (22.0%) | 2680 (21.9%) | 410 (22.7%) | ||
| 5 | 3459 (24.6%) | 3159 (25.8%) | 300 (16.6%) | ||
| Johns Hopkins ADG Comorbidity score | 0–n (%) | 105 (0.7%) | 94 (0.8%) | 11 (0.6%) | 0.77 |
| 1–5 | 5684 (40.4%) | 4967 (40.5%) | 717 (39.7%) | ||
| 6–9 | 5741 (40.8%) | 4989 (40.7%) | 752 (41.6%) | ||
| 10 + | 2526 (18.0%) | 2200 (18.0%) | 326 (18.1%) | ||
| Geographic location | Rural—n (%) | 852 (6.1%) | 839 (6.8%) | 13 (0.7%) | < 0.01 |
| Urban | 13,204 (93.9%) | 11,411 (93.2%) | 1793 (99.3%) | ||
| Neighborhood dependency quintile | 1–n (%) | 3296 (23.4%) | 2541 (20.7%) | 755 (41.8%) | < 0.01 |
| 2 | 2731 (19.4%) | 2354 (19.2%) | 377 (20.9%) | ||
| 3 | 2628 (18.7%) | 2337 (19.1%) | 291 (16.1%) | ||
| 4 | 2339 (16.6%) | 2151 (17.6%) | 188 (10.4%) | ||
| 5 | 3062 (21.8%) | 2867 (23.4%) | 195 (10.8%) | ||
| Neighborhood deprivation quintile | 1–n (%) | 3113 (22.1%) | 2858 (23.3%) | 255 (14.1%) | < 0.01 |
| 2 | 3148 (22.4%) | 2803 (22.9%) | 345 (19.1%) | ||
| 3 | 2936 (20.9%) | 2548 (20.8%) | 388 (21.5%) | ||
| 4 | 2602 (18.5%) | 2208 (18.0%) | 394 (21.8%) | ||
| 5 | 2257 (16.1%) | 1833 (15.0%) | 424 (23.5%) | ||
| Neighborhood ethnic diversity quintile | 1–n (%) | 2217 (15.8%) | 2171 (17.7%) | 46 (2.5%) | < 0.01 |
| 2 | 2619 (18.6%) | 2529 (20.6%) | 90 (5.0%) | ||
| 3 | 3239 (23.0%) | 3044 (24.8%) | 195 (10.8%) | ||
| 4 | 3147 (22.4%) | 2711 (22.1%) | 436 (24.1%) | ||
| 5 | 2834 (20.2%) | 1795 (14.7%) | 1039 (57.5%) | ||
| Neighborhood instability quintile | 1–n (%) | 2769 (19.7%) | 2249 (18.4%) | 520 (28.8%) | < 0.01 |
| 2 | 2555 (18.2%) | 2245 (18.3%) | 310 (17.2%) | ||
| 3 | 2703 (19.2%) | 2478 (20.2%) | 225 (12.5%) | ||
| 4 | 2595 (18.5%) | 2344 (19.1%) | 251 (13.9%) | ||
| 5 | 3434 (24.4%) | 2934 (24.0%) | 500 (27.7%) | ||
| Cancer stage | I–n (%) | 6351 (45.2%) | 5636 (46.0%) | 715 (39.6%) | < 0.01 |
| II | 5471 (38.9%) | 4725 (38.6%) | 746 (41.3%) | ||
| III | 2081 (14.8%) | 1760 (14.4%) | 321 (17.8%) | ||
| IV | 153 (1.1%) | 129 (1.1%) | 24 (1.3%) | ||
| Presence on primary physician roster within 2 years of diagnosis | No–n (%) | 1474 (10.5%) | 1179 (9.6%) | 295 (16.3%) | < 0.01 |
| Yes | 12,582 (89.5%) | 11,071 (90.4%) | 1511 (83.7%) | ||
| HR status | Negative—n (%) | 1915 (13.6%) | 1658 (13.5%) | 257 (14.2%) | 0.60 |
| Positive | 10,068 (71.6%) | 8792 (71.8%) | 1276 (70.7%) | ||
| Unknown | 2073 (14.7%) | 1800 (14.7%) | 273 (15.1%) | ||
| HER2 status | Negative—n (%) | 7133 (50.7%) | 6235 (50.9%) | 898 (49.7%) | < 0.01 |
| Positive—n (%) | 1293 (9.2%) | 1078 (8.8%) | 215 (11.9%) | ||
| Unknown | 5630 (40.1%) | 4937 (40.3%) | 693 (38.4%) | ||
| Grade | 1–n (%) | 2112 (15.0%) | 1926 (15.7%) | 186 (10.3%) | < 0.01 |
| 2 | 5202 (37.0%) | 4562 (37.2%) | 640 (35.4%) | ||
| 3 | 3737 (26.6%) | 3201 (26.1%) | 536 (29.7%) | ||
| Unknown | 3005 (21.4%) | 2561 (20.9%) | 444 (24.6%) | ||
| Surgery | BCS—n (%) | 8976 (63.9%) | 7905 (64.5%) | 1071 (59.3%) | < 0.001 |
| Mastectomy | 5080 (36.1%) | 4345 (35.5%) | 735 (40.7%) | ||
| Received radiation therapy within 12 months of surgery | No—n (%) | 3730 (26.5%) | 3286 (26.8%) | 444 (24.6%) | 0.04 |
| Yes | 10,326 (73.5%) | 8964 (73.2%) | 1362 (75.4%) | ||
| Received chemotherapy within 6 months of diagnosis | No—n (%) | 6371 (45.3%) | 5686 (46.4%) | 685 (37.9%) | < 0.01 |
| Yes | 7685 (54.7%) | 6564 (53.6%) | 1121 (62.1%) |
ADG aggregated diagnosis groups, HR hormone receptor, BCS breast conserving surgery