Table 1.
Baseline characteristics in 5500 patients who underwent pulmonary resections for lung cancer in Sweden during 2008–2017 according to quintiles of household disposable income
| All patients | Household disposable income by quintile | P value | |||||
| Q1 (low) | Q2 | Q3 | Q4 | Q5 (high) | |||
| Number of patients | 5500 | 1100 | 1100 | 1100 | 1100 | 1100 | |
| Age, years, mean (SD) | 68.0 (8.1) | 69.3 (8.4) | 68.7 (8.3) | 68.7 (8.2) | 67.7 (7.5) | 65.5 (7.8) | <0.001 |
| Female sex | 3030 (55.1) | 680 (61.8) | 616 (56.0) | 584 (53.1) | 576 (52.4) | 574 (52.2) | <0.001 |
| Body mass index, kg/m2, mean (SD) | 25.9 (4.8) | 25.9 (5.0) | 25.6 (5.0) | 26.0 (4.7) | 26.0 (4.5) | 26.2 (4.7) | 0.107 |
| Household composition | <0.001 | ||||||
| Two adults, no children | 2425 (44.1) | 56 (5.1) | 295 (26.8) | 642 (58.4) | 768 (69.8) | 664 (60.4) | |
| One adult, no children | 2260 (41.1) | 1016 (92.4) | 711 (64.6) | 334 (30.4) | 126 (11.5) | 73 (6.6) | |
| 1–2 adults and ≥1 child(ren) | 815 (14.8) | 28 (2.5) | 94 (8.5) | 124 (11.3) | 206 (18.7) | 363 (33.0) | |
| Education | <0.001 | ||||||
| <10 years | 1981 (36.0) | 500 (45.5) | 461 (41.9) | 392 (35.6) | 383 (34.8) | 245 (22.3) | |
| 10–12 years | 2452 (44.6) | 499 (45.4) | 484 (44.0) | 512 (46.5) | 504 (45.8) | 453 (41.2) | |
| >12 years | 1067 (19.4) | 101 (9.2) | 155 (14.1) | 196 (17.8) | 213 (19.4) | 402 (36.5) | |
| Household disposable income, kSEK, mean (SD) | 311 (171) | 128 (233) | 201 (210) | 273 (228) | 372 (340) | 580 (142) | <0.001 |
| Smoking status | <0.001 | ||||||
| Never smoker | 851 (15.5) | 141 (12.8) | 151 (13.7) | 178 (16.2) | 175 (15.9) | 206 (18.7) | |
| Former smoker | 2907 (52.9) | 493 (44.8) | 570 (51.8) | 589 (53.5) | 629 (57.2) | 626 (56.9) | |
| Current smoker | 1644 (29.9) | 442 (40.2) | 355 (32.3) | 315 (28.6) | 278 (25.3) | 254 (23.1) | |
| Unknown | 98 (1.8) | 24 (2.2) | 24 (2.2) | 18 (1.6) | 18 (1.6) | 14 (1.3) | |
| Alcohol dependency | 330 (6.0) | 120 (10.9) | 69 (6.3) | 56 (5.1) | 46 (4.2) | 39 (3.5) | <0.001 |
| Preoperative FEV1, L, mean (SD) | 2.24 (0.68) | 2.07 (0.64) | 2.18 (0.68) | 2.22 (0.64) | 2.26 (0.67) | 2.46 (0.72) | <0.001 |
| Performance status | <0.001 | ||||||
| 0 | 3411 (62.0) | 622 (56.5) | 666 (60.5) | 666 (60.5) | 703 (63.9) | 754 (68.5) | |
| 1 | 1984 (36.1) | 451 (41.0) | 411 (37.4) | 410 (37.3) | 377 (34.3) | 335 (30.5) | |
| 2–3 | 105 (1.9) | 27 (2.5) | 23 (2.1) | 24 (2.2) | 20 (1.8) | 11 (1.0) | |
| Hypertension | 2043 (37.1) | 429 (39.0) | 425 (38.6) | 408 (37.1) | 403 (36.6) | 378 (34.4) | 0.169 |
| Ischaemic heart disease | 972 (17.7) | 217 (19.7) | 192 (17.5) | 198 (18.0) | 198 (18.0) | 167 (15.2) | 0.089 |
| Atrial fibrillation | 475 (8.6) | 98 (8.9) | 96 (8.7) | 93 (8.5) | 102 (9.3) | 86 (7.8) | 0.798 |
| Hyperlipidaemia | 693 (12.6) | 148 (13.5) | 139 (12.6) | 146 (13.3) | 129 (11.7) | 131 (11.9) | 0.659 |
| Heart failure | 295 (5.4) | 82 (7.5) | 52 (4.7) | 62 (5.6) | 55 (5.0) | 44 (4.0) | 0.005 |
| COPD | 991 (18.0) | 251 (22.8) | 221 (20.1) | 210 (19.1) | 171 (15.5) | 138 (12.5) | <0.001 |
| Diabetes mellitus | 763 (13.9) | 170 (15.5) | 157 (14.3) | 154 (14.0) | 172 (15.6) | 110 (10.0) | 0.001 |
| Prior stroke/TIA | 507 (9.2) | 121 (11.0) | 116 (10.5) | 99 (9.0) | 83 (7.5) | 88 (8.0) | 0.016 |
| Peripheral vascular disease | 454 (8.3) | 108 (9.8) | 108 (9.8) | 94 (8.5) | 80 (7.3) | 64 (5.8) | 0.002 |
| Chronic kidney disease | 114 (2.1) | 20 (1.8) | 29 (2.6) | 24 (2.2) | 21 (1.9) | 20 (1.8) | 0.621 |
| Preoperative radiotherapy | 166 (3.1) | 38 (3.5) | 26 (2.4) | 32 (3.0) | 34 (3.2) | 36 (3.3) | 0.630 |
| Preoperative chemotherapy | 224 (4.2) | 46 (4.3) | 35 (3.3) | 42 (3.9) | 43 (4.0) | 58 (5.4) | 0.174 |
| Preoperative PET | 4615 (90.0) | 898 (88.2) | 915 (90.3) | 909 (89.0) | 923 (90.2) | 970 (92.1) | 0.039 |
| Lobectomy or more | 4465 (81.2) | 884 (80.4) | 900 (81.8) | 876 (79.6) | 897 (81.5) | 908 (82.5) | 0.416 |
| VATS | 1166 (21.2) | 207 (18.8) | 213 (19.4) | 216 (19.6) | 231 (21.0) | 299 (27.2) | <0.001 |
| Expanded surgery* | 230 (4.2) | 57 (5.2) | 44 (4.0) | 52 (4.7) | 37 (3.4) | 40 (3.6) | 0.177 |
| Lymph node sampling | 4610 (86.1) | 920 (86.0) | 922 (86.5) | 901 (84.4) | 916 (85.2) | 951 (88.4) | 0.083 |
| Incomplete resection | 258 (4.7) | 48 (4.4) | 59 (5.4) | 52 (4.7) | 53 (4.8) | 46 (4.2) | 0.725 |
| Postoperative histopathology | <0.001 | ||||||
| Squamous cell lung cancer | 1036 (18.8) | 242 (22.0) | 240 (21.8) | 190 (17.3) | 209 (19.0) | 155 (14.1) | |
| Adenocarcinoma | 3266 (59.4) | 592 (53.8) | 632 (57.5) | 656 (59.6) | 656 (59.6) | 730 (66.4) | |
| Other | 638 (11.6) | 127 (11.5) | 127 (11.5) | 134 (12.2) | 132 (12.0) | 118 (10.7) | |
| Unknown | 560 (10.2) | 139 (12.6) | 101 (9.2) | 120 (10.9) | 103 (9.4) | 97 (8.8) | |
| Stage† | 0.055 | ||||||
| IA | 2148 (39.1) | 398 (36.2) | 408 (37.1) | 443 (40.3) | 431 (39.2) | 468 (42.5) | |
| IB | 1276 (23.2) | 271 (24.6) | 282 (25.6) | 252 (22.9) | 251 (22.8) | 220 (20.0) | |
| IIA | 701 (12.7) | 139 (12.6) | 148 (13.5) | 143 (13.0) | 139 (12.6) | 132 (12.0) | |
| IIB | 608 (11.1) | 129 (11.7) | 133 (12.1) | 115 (10.5) | 118 (10.7) | 113 (10.3) | |
| IIIA | 767 (13.9) | 163 (14.8) | 129 (11.7) | 147 (13.4) | 161 (14.6) | 167 (15.2) | |
Data are n (%) unless otherwise noted.
*If any structure other than the lung or lymph nodes was included in the resection (eg, pericardium, diaphragm, thoracic wall).
†Pathological stage.
kSEK, 1000 Swedish Krona; PET, positron emission tomography; Q, quintile; TIA, transient ischaemic attack; VATS, video-assisted thoracic surgery.