Table 1.
Overall Hospitalized Adult Influenza Vaccine Effectiveness Network Study Population, Combined Years (N = 6129)a
| Characteristic | Overall | Influenza Positive | Influenza Negative | P Value | Vaccinated | Not Vaccinated | P Value | Received Cell-Based Vaccine | |
|---|---|---|---|---|---|---|---|---|---|
| 2016–2017 | 2017–2018 | ||||||||
| Season | |||||||||
| 2016–2017 | 2605 (42.5) | 463 (17.8) | 2142 (82.2) | <.001 | 1886 (72.4) | 719 (27.6) | <.001 | 9 (0.5) | -- |
| 2017–2018 | 3524 (57.5) | 910 (25.8) | 2614 (74.2) | 2350 (66.7) | 1174 (33.3) | -- | 66 (2.8) | ||
| Study site | |||||||||
| Michigan | 1610 (26.3) | 412 (25.6) | 1198 (74.4) | .002 | 1089 (67.6) | 521 (32.4) | .002 | 2 (0.4) | 31 (5.0) |
| Pennsylvania | 1716 (28.0) | 385 (22.4) | 1331 (77.6) | 1229 (71.6) | 487 (28.4) | 1 (0.2) | 12 (2.1) | ||
| Tennessee | 1194 (19.5) | 246 (20.6) | 948 (79.4) | 851 (71.3) | 343 (28.7) | 6 (1.4) | 15 (3.7) | ||
| Texas | 1609 (26.3) | 330 (20.5) | 1279 (79.5) | 1067 (66.3) | 542 (33.7) | 0 (0.0) | 8 (1.1) | ||
| Sex | |||||||||
| Female | 3467 (56.6) | 777 (22.4) | 2690 (77.6) | .984 | 2406 (69.4) | 1061 (30.6) | .584 | 6 (0.6) | 34 (2.5) |
| Male | 2662 (43.4) | 596 (22.4) | 2066 (77.6) | 1830 (68.7) | 832 (31.3) | 3 (0.4) | 32 (3.2) | ||
| Age group, y | |||||||||
| 18–49 | 1376 (22.5) | 274 (19.9) | 1102 (80.1) | <.001 | 759 (55.2) | 617 (44.8) | <.001 | 2 (0.6) | 15 (3.7) |
| 50–64 | 2074 (33.8) | 415 (20.0) | 1659 (80.0) | 1323 (63.8) | 751 (36.2) | 5 (0.8) | 33 (4.7) | ||
| 65–74 | 1388 (22.6) | 317 (22.8) | 1071 (77.2) | 1043 (75.1) | 345 (24.9) | 0 (0.0) | 6 (1.0) | ||
| 75+ | 1291 (21.1) | 367 (28.4) | 924 (71.6) | 1111 (86.1) | 180 (13.9) | 2 (0.4) | 12 (1.8) | ||
| Race and ethnicity | |||||||||
| White, non-Hispanic | 3979 (65.0) | 858 (21.6) | 3121 (78.4) | .21 | 2908 (73.1) | 1071 (26.9) | <.001 | 5 (0.4) | 39 (2.5) |
| Black, non-Hispanic | 1723 (28.2) | 411 (23.9) | 1312 (76.1) | 1061 (61.6) | 662 (38.4) | 3 (0.7) | 25 (3.9) | ||
| Other race, non-Hispanic | 183 (3.0) | 43 (23.5) | 140 (76.5) | 117 (63.9) | 66 (36.1) | 0 (0.0) | 1 (1.6) | ||
| Hispanic, any race | 235 (3.8) | 58 (24.7) | 177 (75.3) | 147 (62.6) | 88 (37.4) | 1 (2.0) | 1 (1.0) | ||
| Vaccinated in prior season | |||||||||
| Yes | 4614 (76.2) | 956 (20.7) | 3658 (79.3) | <.001 | 3921 (85.0) | 693 (15.0) | <.001 | 8 (0.5) | 58 (2.7) |
| No | 1438 (23.8) | 395 (27.5) | 1043 (72.5) | 275 (19.1) | 1163 (80.9) | 1 (0.8) | 6 (4.1) | ||
| High risk in past year | |||||||||
| Yes | 5913 (96.5) | 1304 (22.1) | 4609 (77.9) | <.001 | 4130 (69.8) | 1783 (30.2) | <.001 | 7 (0.4) | 59 (2.6) |
| No | 216 (3.5) | 69 (31.9) | 147 (68.1) | 106 (49.1) | 110 (50.9) | 2 (8.7) | 7 (8.4) | ||
| Self-reported health | |||||||||
| Poor | 961 (15.7) | 155 (16.1) | 806 (83.9) | <.001 | 679 (70.7) | 282 (29.3) | <.001 | 3 (1.0) | 8 (2.1) |
| Fair | 2104 (34.3) | 442 (21.0) | 1662 (79.0) | 1529 (72.7) | 575 (27.3) | 2 (0.3) | 24 (2.9) | ||
| Good | 1918 (31.3) | 480 (25.0) | 1438 (75.0) | 1322 (68.9) | 596 (31.1) | 2 (0.4) | 23 (3.0) | ||
| Very good | 828 (13.5) | 211 (25.5) | 617 (74.5) | 518 (62.6) | 310 (37.4) | 2 (0.9) | 8 (2.8) | ||
| Excellent | 318 (5.2) | 85 (26.7) | 233 (73.3) | 188 (59.1) | 130 (40.9) | 0 (0.0) | 3 (3.3) | ||
| Charlson comorbidity index | |||||||||
| 0 | 504 (8.2) | 159 (31.5) | 345 (68.5) | <.001 | 272 (54.0) | 232 (46.0) | <.001 | 1 (0.9) | 10 (6.3) |
| 1 | 1080 (17.6) | 264 (24.4) | 816 (75.6) | 602 (55.7) | 478 (44.3) | 0 (0.0) | 8 (2.5) | ||
| 2–3 | 1736 (28.3) | 382 (22.0) | 1354 (78.0) | 1194 (68.8) | 542 (31.2) | 2 (0.4) | 22 (3.3) | ||
| 4+ | 2809 (45.8) | 568 (20.2) | 2241 (79.8) | 2168 (77.2) | 641 (22.8) | 6 (0.6) | 26 (2.1) | ||
| Frailty level | |||||||||
| 0 | 1096 (18.2) | 313 (28.6) | 783 (71.4) | <.001 | 696 (63.5) | 400 (36.5) | <.001 | 1 (0.3) | 13 (3.4) |
| 1 | 1323 (21.9) | 294 (22.2) | 1029 (77.8) | 886 (67.0) | 437 (33.0) | 2 (0.5) | 17 (3.5) | ||
| 2 | 1253 (20.8) | 263 (21.0) | 990 (79.0) | 873 (69.7) | 380 (30.3) | 3 (0.8) | 14 (2.8) | ||
| 3 | 1086 (18.0) | 240 (22.1) | 846 (77.9) | 771 (71.0) | 315 (29.0) | 1 (0.3) | 10 (2.3) | ||
| 4 | 912 (15.1) | 178 (19.5) | 734 (80.5) | 681 (74.7) | 231 (25.3) | 2 (0.7) | 7 (1.9) | ||
| 5 | 366 (6.1) | 62 (16.9) | 304 (83.1) | 266 (72.7) | 100 (27.3) | 0 (0.0) | 4 (3.0) | ||
| Days from onset to specimen collection | |||||||||
| 0–2 | 2253 (36.8) | 533 (23.7) | 1720 (76.3) | <.001 | 1599 (71.0) | 654 (29.0) | .081 | 3 (0.4) | 20 (2.3) |
| 3–4 | 1734 (28.3) | 425 (24.5) | 1309 (75.5) | 1175 (67.8) | 559 (32.2) | 4 (0.8) | 16 (2.3) | ||
| 5–7 | 1481 (24.2) | 306 (20.7) | 1175 (79.3) | 1020 (68.9) | 461 (31.1) | 2 (0.5) | 19 (3.3) | ||
| 8–10 | 661 (10.8) | 109 (16.5) | 552 (83.5) | 442 (66.9) | 219 (33.1) | 0 (0.0) | 11 (5.2) | ||
| Self-reported number of hospitalizations in past year | |||||||||
| 0 | 2339 (38.2) | 679 (29.0) | 1660 (71.0) | <.001 | 1469 (62.8) | 870 (37.2) | <.001 | 3 (0.5) | 21 (2.5) |
| 1 | 1153 (18.8) | 264 (22.9) | 889 (77.1) | 790 (68.5) | 363 (31.5) | 2 (0.5) | 15 (3.6) | ||
| 2 | 772 (12.6) | 151 (19.6) | 621 (80.4) | 550 (71.2) | 222 (28.8) | 1 (0.4) | 5 (1.7) | ||
| 3 | 522 (8.5) | 105 (20.1) | 417 (79.9) | 395 (75.7) | 127 (24.3) | 1 (0.6) | 7 (3.1) | ||
| 4+ | 1343 (21.9) | 174 (13.0) | 1169 (87.0) | 1032 (76.8) | 311 (23.2) | 2 (0.4) | 18 (3.2) |
Data are n (%). Row percents are displayed for all columns except the Overall.
aSixty participants had 2–4 enrollments (giving a total of 69 additional enrollments) in 2016–2017; 113 participants had 2–6 enrollments (giving a total of 134 additional enrollments) in 2017–2018.