| Cases | Control 1 | Control 2 | Control 3 | ||||
| Data | p-value¶ | Data | p-value¶ | Data | p-value¶ | ||
| Patients n | 489 | 489 | 489 | 489 | |||
| Age yrs | 77.2±6.7 | 77.1±6.3 | 0.388 | 77.3±6.4 | 0.489 | 76.6±6.2 | 0.001 |
| History of pneumonia | 119 (25.3) | 76(16.3) | 0.001 | 74 (15.7) | <0.001 | 42 (9.0) | <0.001 |
| Influenza vaccination | 306 (62.6) | 322 (65.8) | 0.258 | 320 (65.4) | 0.340 | 325 (66.5) | 0.202 |
| Pneumococcal vaccination | 229 (46.8) | 258 (52.8) | 0.037 | 243 (49.7) | 0.307 | 249 (50.9) | 0.161 |
| Visited doctor in past year | 449 (93.0) | 452 (92.8) | 1.00 | 447 (92.2) | 0.791 | 454 (93.4) | 0.784 |
| Time since vaccination days | 1548±664 | 1436±694 | 0.048 | 1502±698 | 0.642 | 1447±719 | 0.026 |
| Solid organ neoplasia | 51 (10.4) | 85 (17.4) | <0.001 | 90 (18.4) | <0.001 | 129 (26.4) | <0.001 |
| Haematologic neoplasia | 43 (8.8) | 23 (4.7) | 0.006 | 16 (3.3) | <0.001 | 14 (2.9) | <0.001 |
| Solid organ transplant | 3 (0.6) | 3 (0.6) | 1.00 | 1 (0.2) | 0.625 | 3 (0.6) | 1.00 |
| Bone marrow transplant | 2 (0.4) | 1 (0.2) | 1.00 | 1 (0.2) | 1.00 | 0 (0.0) | 0.500 |
| Radiotherapy | 4 (0.8) | 5 (1.0) | 1.00 | 3 (0.6) | 1.00 | 2 (0.4) | 0.688 |
| Immunosuppressive therapy | 18 (3.7) | 10 (2.0) | 0.115 | 14 (2.9) | 0.571 | 12 (2.5) | 0.307 |
| Corticosteroid therapy | 24 (4.9) | 16 (3.3) | 0.134 | 12 (2.5) | 0.023 | 9 (1.8) | 0.004 |
| Splenectomy | 4 (0.8) | 4 (0.8) | 1.00 | 1 (0.2) | 0.375 | 5 (1.0) | 1.00 |
| Autoimmune disease | 14 (2.9) | 22 (4.5) | 0.152 | 12 (2.5) | 0.791 | 10 (2.0) | 0.503 |
| Chronic renal failure with dialysis | 12 (2.5) | 6 (1.2) | 0.180 | 12 (2.5) | 1.00 | 5 (1.0) | 0.118 |
| Disabling neurological disease | 82 (16.8) | 81 (16.6) | 1.00 | 82 (16.8) | 1.00 | 55 (11.2) | <0.001 |
| Diabetes mellitus | 108 (22.1) | 135 (27.6) | 0.013 | 123 (25.2) | 0.184 | 135 (27.6) | 0.009 |
| Heart failure, grade 3 or 4 | 48 (9.8) | 54 (11.0) | 0.496 | 63 (12.9) | 0.082 | 40 (8.2) | 0.312 |
| COPD | 180 (36.8) | 153 (31.3) | 0.004 | 159 (32.5) | 0.021 | 130 (26.6) | <0.001 |
| Chronic liver disease | 16 (3.3) | 17 (3.5) | 1.00 | 16 (3.3) | 1.00 | 9 (1.8) | 0.167 |
| Renal failure, no dialysis | 22 (4.5) | 37 (7.6) | 0.041 | 27 (5.5) | 0.551 | 16 (3.3) | 0.405 |
| Chronic alcoholism | 40 (9.3) | 31 (7.2) | 0.203 | 40 (9.5) | 0.779 | 29 (7.0) | 0.243 |
| Smoker or ex-smoker | 267 (54.9) | 251 (51.6) | 0.136 | 250 (51.3) | 0.139 | 239 (49.1) | 0.015 |
Data are presented as n (%) or mean±sd, unless otherwise stated. COPD: chronic obstructive pulmonary disease; #: strata I, II and III combined; ¶: compared with cases.