Demographic features of the study cohorts
| Before propensity score matching | After propensity score matching# | |||||||||
| n | FV-positive (n=142) | FV-negative (n=105) | Combined (n=247) | p-value | n | FV-positive (n=105) | FV-negative (n=105) | Combined (n=210) | p-value | |
| Race | 247 | 0.921 | 210 | 0.448 | ||||||
| White | 129 (91) | 95 (90) | 224 (91) | 98 (93) | 95 (90) | 193 (92) | ||||
| Non-White | 13 (9) | 10 (10) | 23 (9) | 7 (7) | 10 (10) | 17 (8) | ||||
| Gender | 247 | 0.393 | 210 | 0.889 | ||||||
| Male | 72 (51) | 59 (56) | 131 (53) | 60 (57) | 59 (56) | 119 (57) | ||||
| Female | 70 (49) | 46 (44) | 116 (47) | 45 (43) | 46 (44) | 91 (43) | ||||
| Age, years | 247 | 0.550 | 210 | 0.537 | ||||||
| <60 | 47 (33) | 31 (30) | 78 (32) | 27 (26) | 31 (30) | 58 (28) | ||||
| ≥60 | 95 (67) | 74 (70) | 169 (68) | 78 (74) | 74 (70) | 152 (72) | ||||
| Smoking status | 247 | 0.219 | 210 | 1 | ||||||
| Ever-smoker | 126 (89) | 98 (93) | 224 (91) | 98 (93) | 98 (93) | 196 (93) | ||||
| Never-smoker | 16 (11) | 7 (7) | 23 (9) | 7 (7) | 7 (7) | 14 (7) | ||||
| Cancer type | 247 | 0.126 | 210 | 0.260 | ||||||
| NSCLC | 124 (87) | 86 (82) | 210 (85) | 89 (85) | 86 (82) | 175 (83) | ||||
| SCLC | 10 (7) | 16 (15) | 26 (11) | 9 (9) | 16 (15) | 25 (12) | ||||
| Mixed NSCLC/ SCLC | 3 (2) | 2 (2) | 5 (2) | 3 (3) | 2 (2) | 5 (2) | ||||
| Others | 5 (4) | 1 (1) | 6 (2) | 4 (4) | 1 (1) | 5 (2) | ||||
| Malignant mesothelioma | 4 (3) | 0 (0) | 4 (2) | 4 (4) | 0 (0) | 4 (2) | ||||
| Thymic cancer | 1 (1) | 1 (1) | 2 (1) | 0 (0) | 1 (1) | 1 (0) | ||||
| Stage | 247 | 0.479 | 210 | 1 | ||||||
| III | 13 (9) | 7 (7) | 20 (8) | 7 (7) | 7 (7) | 14 (7) | ||||
| IV | 129 (91) | 98 (93) | 227 (92) | 98 (93) | 98 (93) | 196 (93) | ||||
| Trial patient | 247 | 0.326 | 210 | 0.471 | ||||||
| Yes | 56 (39) | 35 (33) | 91 (37) | 40 (38) | 35 (33) | 75 (36) | ||||
| No | 86 (61) | 70 (67) | 156 (63) | 65 (62) | 70 (67) | 135 (64) | ||||
| ICI received¶ | 247 | 0.163 | 210 | 0.284 | ||||||
| PD-1 inhibitor | 111 (78) | 81 (77) | 192 (78) | 83 (79) | 81 (77) | 164 (78) | ||||
| PD-L1 inhibitor | 19 (13) | 11 (10) | 30 (12) | 10 (10) | 11 (10) | 21 (10) | ||||
| CTLA-4 inhibitor | 3 (2) | 0 (0) | 3 (1) | 3 (3) | 0 (0) | 3 (1) | ||||
| CTLA-4 combination | 9 (6) | 13 (12) | 22 (9) | 9 (9) | 13 (12) | 22 (10) | ||||
| Best ICI response | 247 | 0.396 | 210 | 0.474 | ||||||
| PD | 48 (34) | 41 (39) | 89 (36) | 36 (34) | 41 (39) | 77 (37) | ||||
| Responses other than PD | 94 (66) | 64 (61) | 158 (64) | 69 (66) | 64 (61) | 133 (63) | ||||
| Comorbidities, n | 234 | 0.905 | 210 | 0.719 | ||||||
| 0 | 2 (2) | 1 (1) | 3 (1) | 3 (3) | 1 (1) | 4 (2) | ||||
| 1 | 39 (30) | 29 (28) | 68 (29) | 33 (31) | 30 (29) | 63 (30) | ||||
| 2 | 33 (25) | 30 (29) | 63 (27) | 28 (27) | 31 (30) | 59 (28) | ||||
| ≥3 | 57 (44) | 43 (42) | 100 (43) | 41 (39) | 43 (41) | 84 (40) | ||||
| Comorbidity | ||||||||||
| Cardiovascular | 234 | 85 (65) | 68 (66) | 153 (65) | 0.856 | 210 | 68 (65) | 69 (66) | 137 (65) | 0.885 |
| Pulmonary | 234 | 53 (40) | 50 (49) | 103 (44) | 0.216 | 210 | 50 (48) | 50 (48) | 100 (48) | 1 |
| Metabolic | 234 | 53 (40) | 47 (46) | 100 (43) | 0.427 | 210 | 43 (41) | 47 (45) | 90 (43) | 0.577 |
| Second primary cancers | 234 | 34 (26) | 17 (17) | 51 (22) | 0.082 | 210 | 18 (17) | 17 (16) | 35 (17) | 0.853 |
| Autoimmune | 234 | 25 (19) | 27 (26) | 52 (22) | 0.193 | 210 | 23 (22) | 28 (27) | 51 (24) | 0.421 |
| Nephrology/ urology | 234 | 16 (12) | 15 (15) | 31 (13) | 0.599 | 204 | 11 (11) | 15 (15) | 26 (13) | 0.432 |
| Cerebrovascular | 234 | 13 (10) | 11 (11) | 24 (10) | 0.850 | 204 | 8 (8) | 11 (11) | 19 (9) | 0.498 |
| Neurological | 234 | 6 (5) | 8 (8) | 14 (6) | 0.308 | 204 | 4 (4) | 8 (8) | 12 (6) | 0.248 |
| Influenza prodromes | 247 | 0.830 | 210 | 0.313 | ||||||
| Yes | 2 (1) | 3 (3) | 5 (2) | 1 (1) | 3 (3) | 4 (2) | ||||
| No | 140 (99) | 102 (97) | 242 (98) | 104 (99) | 102 (97) | 206 (98) | ||||
| Influenza-related hospitalisation | 247 | 0.419 | 210 | 0.316 | ||||||
| Yes | 1 (1) | 1 (1) | 2 (1) | 0 (0) | 1 (1) | 1 (0) | ||||
| No | 141 (99) | 104 (99) | 245 (99) | 105 (100) | 104 (99) | 209 (100) | ||||
Data are presented as n (%), unless otherwise stated. FV: influenza vaccination; NSCLC: nonsmall cell lung cancer; SCLC: small cell lung cancer; ICI: immune checkpoint inhibitor; PD-1: programmed cell death 1; PD-L1: PD-1 ligand 1; CTLA-4: cytotoxic T-lymphocyte antigen 4; PD: progressive disease. #: one of the five propensity score matching model runs after multiple imputations (numbers change very slightly among five runs); ¶: PD-1 inhibitors include nivolumab and pembrolizumab; PD-L1 inhibitors include atezolizumab and durvalumab; CTLA-4 inhibitor here indicates ipilimumab; CTLA-4 combinations include ipilimumab plus nivolumab and tremelimumab plus durvalumab.