Table 1.
Patient characteristics in the matched population for each season
| Season 2014–2015 |
Season 2015–2016 |
Season 2016–2017 |
Season 2017–2018 |
|||||
|---|---|---|---|---|---|---|---|---|
| Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | |
| No. of patients | 7,503 | 7,503 | 10,318 | 10,318 | 12,723 | 12,723 | 13,927 | 13,927 |
| Age, yr, mean (SD) | 68.9 (11.7) | 69.0 (11.7) | 69.4 (11.6) | 69.5 (11.6) | 69.8 (11.7) | 69.9 (11.6) | 69.8 (11.8) | 70.0 (11.7) |
| Age groups, yr, n (%) | ||||||||
| 20–29 | 23 (0.3) | 23 (0.3) | 13 (0.1) | 13 (0.1) | 22 (0.2) | 22 (0.2) | 20 (0.1) | 20 (0.1) |
| 30–39 | 101 (1.3) | 101 (1.3) | 105 (1.0) | 105 (1.0) | 135 (1.1) | 135 (1.1) | 163 (1.2) | 163 (1.2) |
| 40–49 | 359 (4.8) | 359 (4.8) | 499 (4.8) | 499 (4.8) | 558 (4.4) | 558 (4.4) | 573 (4.1) | 573 (4.1) |
| 50–59 | 1,079 (14.4) | 1,079 (14.4) | 1,470 (14.2) | 1,470 (14.2) | 1,743 (13.7) | 1,743 (13.7) | 1,912 (13.7) | 1,912 (13.7) |
| 60–69 | 1,669 (22.2) | 1,669 (22.2) | 2,445 (23.7) | 2,445 (23.7) | 3,081 (24.2) | 3,081 (24.2) | 3,456 (24.8) | 3,456 (24.8) |
| 70–79 | 2,998 (40.0) | 2,998 (40.0) | 3,770 (36.5) | 3,770 (36.5) | 4,400 (34.6) | 4,400 (34.6) | 4,616 (33.1) | 4,616 (33.1) |
| 80–89 | 1,261 (16.8) | 1,261 (16.8) | 1,970 (19.1) | 1,970 (19.1) | 2,717 (21.4) | 2,717 (21.4) | 3,109 (22.3) | 3,109 (22.3) |
| 90 + | 13 (0.2) | 13 (0.2) | 46 (0.4) | 46 (0.4) | 67 (0.5) | 67 (0.5) | 78 (0.6) | 78 (0.6) |
| Sex, male, n (%) | 3,613 (48.2) | 3,613 (48.2) | 4,909 (47.6) | 4,909 (47.6) | 6,090 (47.9) | 6,090 (47.9) | 6,632 (47.6) | 6,632 (47.6) |
| ILD diagnosis (ICD-10), n (%) | ||||||||
| Idiopathic interstitial pneumonia | 3,306 (44.1) | 3,306 (44.1) | 4,443 (43.1) | 4,443 (43.1) | 5,440 (42.8) | 5,440 (42.8) | 5,767 (41.4) | 5,767 (41.4) |
| Other fibrosing ILDs | 853 (11.4) | 853 (11.4) | 1,428 (13.8) | 1,428 (13.8) | 2,004 (15.8) | 2,004 (15.8) | 2,380 (17.1) | 2,380 (17.1) |
| Sarcoidosis | 2,866 (38.2) | 2,866 (38.2) | 3,678 (35.6) | 3,678 (35.6) | 4,284 (33.7) | 4,284 (33.7) | 4,631 (33.3) | 4,631 (33.3) |
| Drug-associated ILDs | 6 (0.1) | 6 (0.1) | 10 (0.1) | 10 (0.1) | 22 (0.2) | 22 (0.2) | 25 (0.2) | 25 (0.2) |
| Pneumoconiosis | 212 (2.8) | 212 (2.8) | 286 (2.8) | 286 (2.8) | 311 (2.4) | 311 (2.4) | 318 (2.3) | 318 (2.3) |
| Radiation-associated pneumonitis | 6 (0.1) | 6 (0.1) | 18 (0.2) | 18 (0.2) | 19 (0.1) | 19 (0.1) | 20 (0.1) | 20 (0.1) |
| Eosinophilic pneumonia | 24 (0.3) | 24 (0.3) | 71 (0.7) | 71 (0.7) | 115 (0.9) | 115 (0.9) | 155 (1.1) | 155 (1.1) |
| Hypersensitivity pneumonitis | 162 (2.2) | 162 (2.2) | 249 (2.4) | 249 (2.4) | 304 (2.4) | 304 (2.4) | 336 (2.4) | 336 (2.4) |
| Connective tissue–associated ILD | 68 (0.9) | 68 (0.9) | 135 (1.3) | 135 (1.3) | 224 (1.8) | 224 (1.8) | 295 (2.1) | 295 (2.1) |
| Elixhauser comorbidity score, mean (SD) | 3.6 (2.0) | 3.6 (2.0) | 3.8 (2.1) | 3.8 (2.1) | 4.0 (2.1) | 4.0 (2.1) | 4.0 (2.2) | 4.0 (2.2) |
| Care dependency,* n (%) | ||||||||
| No care level | 6,953 (92.7) | 6,953 (92.7) | 9,408 (91.2) | 9,408 (91.2) | 11,342 (89.1) | 11,342 (89.1) | 12,150 (87.2) | 12,150 (87.2) |
| Care level 1 | 463 (6.2) | 463 (6.2) | 736 (7.1) | 736 (7.1) | 1,088 (8.6) | 1,088 (8.6) | 86 (0.6) | 86 (0.6) |
| Care level 2 | 83 (1.1) | 83 (1.1) | 172 (1.7) | 172 (1.7) | 279 (2.2) | 279 (2.2) | 1,205 (8.7) | 1,205 (8.7) |
| Care level 3 | 4 (0.1) | 4 (0.1) | 2 (0.0) | 2 (0.0) | 14 (0.1) | 14 (0.1) | 403 (2.9) | 403 (2.9) |
| Care level 4 | — | — | — | — | 0 (0.0) | 0 (0.0) | 79 (0.6) | 79 (0.6) |
| Care level 5 | — | — | — | — | 0 (0.0) | 0 (0.0) | 4 (0.0) | 4 (0.0) |
| Nursing home residency, n (%) | 15 (0.2) | 15 (0.2) | 47 (0.5) | 47 (0.5) | 77 (0.6) | 77 (0.6) | 80 (0.6) | 80 (0.6) |
| Radiotherapy or chemotherapy in 3 mo before matching, n (%) | 10 (0.1) | 10 (0.1) | 39 (0.4) | 39 (0.4) | 80 (0.6) | 80 (0.6) | 106 (0.8) | 106 (0.8) |
Definition of abbreviations: ICD-10 = International Classification of Diseases, Tenth Revision; ILD = interstitial lung disease; SD = standard deviation.
*
Care dependency until 2017 in three levels and after 2017 in five levels.