Immune-related adverse events (IRAEs) in 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 | |
| IRAEs | 247 | 0.419 | 210 | 0.49 | ||||||
| Yes | 67 (47) | 55 (52) | 122 (49) | 50 (48) | 55 (52) | 105 (50) | ||||
| No | 75 (53) | 50 (48) | 125 (51) | 55 (52) | 50 (48) | 105 (50) | ||||
| IRAE severity grading | 247 | 0.004* | 210 | 0.004* | ||||||
| Grade 5 | 1 (1) | 0 (0) | 1 (0) | 1 (1) | 0 (0) | 1 (0) | ||||
| Grade 4 | 2 (1) | 1 (1) | 3 (1) | 1 (1) | 1 (1) | 2 (1) | ||||
| Grade 3 | 26 (18) | 38 (36) | 64 (26) | 18 (17) | 38 (36) | 56 (27) | ||||
| Grade 2 | 27 (19) | 16 (15) | 43 (17) | 22 (21) | 16 (15) | 38 (18) | ||||
| Grade 1 | 11 (8) | 0 (0) | 11 (4) | 8 (8) | 0 (0) | 8 (4) | ||||
| No IRAEs | 75 (53) | 50 (48) | 125 (51) | 55 (52) | 50 (48) | 105 (50) | ||||
| IRAE severity group | 247 | 0.006* | 210 | 0.005* | ||||||
| Grade 3–5 | 29 (20) | 39 (37) | 68 (28) | 20 (19) | 39 (37) | 59 (28) | ||||
| Grade 1–2 | 38 (27) | 16 (15) | 54 (22) | 30 (29) | 16 (15) | 46 (22) | ||||
| No IRAEs | 75 (53) | 50 (48) | 125 (50) | 55 (52) | 50 (48) | 105 (50) | ||||
| IRAE type | ||||||||||
| Endocrinopathy | 247 | 27¶ (19) | 16+ (15) | 43 (17) | 0.440 | 210 | 22§ (21) | 16ƒ (15) | 38 (18) | 0.282 |
| Hypothyroidism | 21 (15) | 12 (11) | 33 (13) | 17 (16) | 12 (11) | 29 (28) | ||||
| Adrenal insufficiency | 8 (6) | 4 (4) | 12 (5) | 6 (6) | 4 (4) | 10 (10) | ||||
| Hypophysitis | 1 (1) | 1 (1) | 2 (1) | 1 (1) | 1 (1) | 2 (2) | ||||
| Pneumonitis | 247 | 17 (12) | 18 (17) | 35 (14) | 0.250 | 210 | 12 (11) | 18 (17) | 30 (14) | 0.237 |
| Dermatological | 247 | 17 (12) | 7 (7) | 24 (10) | 0.160 | 210 | 14 (13) | 7 (7) | 21 (10) | 0.107 |
| Hepatitis/colitis | 247 | 16 (11) | 8 (8) | 24 (10) | 0.340 | 210 | 8 (8) | 8 (8) | 16 (8) | 1 |
| Hepatitis | 9 (6) | 6 (6) | 15 (6) | 5 (5) | 6 (6) | 11 (5) | ||||
| Colitis | 7 (5) | 2 (2) | 9 (4) | 3 (3) | 2 (2) | 5 (2) | ||||
| Neuromuscular | 247 | 5 (3) | 10 (10) | 15 (6) | 0.051 | 210 | 4 (4) | 10 (10) | 14 (7) | 0.097 |
| Severe fatigue | 247 | 4 (3) | 4 (4) | 8 (3) | 0.660 | 210 | 3 (3) | 4 (4) | 7 (3) | 0.701 |
| Myocarditis | 247 | 1 (1) | 4 (4) | 5 (2) | 0.087 | 210 | 1 (1) | 4 (4) | 5 (2) | 0.174 |
| Haematological | 247 | 0 (0) | 2 (2) | 2 (2) | 1 | 210 | 0 (0) | 2 (2) | 2 (1) | 0.155 |
| Nephritis | 247 | 1 (1) | 0 (0) | 1 (0) | 0.390 | 210 | 1 (1) | 0 (0) | 1 (0) | 0.316 |
| Immunosuppressive agents for IRAEs | 247 | 0.005* | 210 | 0.004* | ||||||
| Yes | 32 (23) | 41 (39) | 73 (30) | 22 (21) | 41 (39) | 63 (30) | ||||
| No | 110 (77) | 64 (61) | 174 (70) | 83 (79) | 64 (61) | 147 (70) | ||||
| ICI discontinuation due to IRAEs | 247 | 0.018* | 210 | 0.014* | ||||||
| Yes | 25 (18) | 32 (30) | 57 (23) | 17 (16) | 32 (30) | 49 (23) | ||||
| No | 117 (82) | 73 (70) | 190 (77) | 88 (84) | 73 (70) | 161 (77) | ||||
| Grade 3–5 IRAEs## | 247 | 0.004* | 210 | 0.004* | ||||||
| Yes | 29 (20) | 39 (37) | 68 (28) | 20 (19) | 39 (37) | 59 (28) | ||||
| No | 113 (80) | 66 (63) | 179 (72) | 85 (81) | 66 (63) | 151 (72) | ||||
Data are presented as n (%), unless otherwise stated. FV: influenza vaccination; ICI: immune checkpoint inhibitor. #: one of the five propensity score matching models run after multiple imputations (the numbers varied very slightly among the five runs); ¶: three patients had both hypothyroidism and adrenal insufficiency; +: one patient had both hypothyroidism and adrenal insufficiency; §: two patients had both hypothyroidism and adrenal insufficiency; ƒ: one patient had both hypothyroidism and adrenal insufficiency; ##: denominator: cases with positive IRAE (annotated as IRAE=Yes in the table). *: p<0.05.