Table 1.
Demographics and Medical History of Older Adult Patients Hospitalized With Laboratory-Confirmed Influenza—FluSurv-NET, 2011–2012 Through 2014–2015 Influenza Seasons (n = 19 760), by Age Group
| 65–74 Years Old | 75–84 Years Old | ≥85 Years Old | ||
|---|---|---|---|---|
| (n = 5956) | (n = 6998) | (n = 6806) | ||
| no. (%) | no. (%) | no. (%) | P a | |
| Season | <.01 | |||
| 2011–2012 | 281 (4.7) | 348 (5.0) | 292 (4.3) | |
| 2012–2013 | 1596 (26.8) | 1969 (28.1) | 1961 (28.8) | |
| 2013–2014 | 1283 (21.5) | 940 (13.4) | 542 (8.0) | |
| 2014–2015 | 2796 (46.9) | 3741 (53.5) | 4011 (58.9) | |
| Female sex | 3114 (42.3) | 3733 (53.3) | 4056 (59.6) | <.01 |
| Non-white raceb | 1297 (24.9) | 1150 (18.8) | 734 (12.3) | <.01 |
| Hispanic ethnicityb | 369 (8.0) | 386 (7.3) | 227 (4.5) | <.01 |
| Nursing home residentb | 666 (11.3) | 1303 (18.8) | 2695 (40.0) | <.01 |
| Morbid obesityb | 580 (10.4) | 330 (5.0) | 105 (1.7) | <.01 |
| Current smoking | 1195 (20.0) | 556 (8.0) | 156 (2.3) | <.01 |
| Current alcohol | 177 (3.0) | 96 (1.4) | 57 (0.8) | <.01 |
| Neurologic disorder | 987 (16.6) | 1777 (25.4) | 2501 (36.8) | <.01 |
| Chronic cardiovascular disease | 3055 (52.3) | 4328 (61.9) | 4500 (66.1) | <.01 |
| Renal disease | 1218 (20.5) | 1764 (25.2) | 1769 (26.0) | <.01 |
| Asthma | 1081 (18.2) | 870 (12.4) | 618 (9.1) | <.01 |
| Chronic lung disease | 2429 (40.8) | 2366 (33.8) | 1683 (24.7) | <.01 |
| Chronic metabolic disease | 2989 (50.2) | 3464 (49.5) | 2947 (43.3) | <.01 |
| Immunosuppressive condition | 1214 (20.4) | 939 (13.4) | 603 (8.9) | <.01 |
| Hemoglobinopathy | 343 (5.8) | 430 (6.1) | 418 (6.1) | .38 |
| Neuromuscular disorder | 373 (6.3) | 462 (6.6) | 409 (6.0) | .52 |
| History of Guillain-Barre Syndrome | 11 (0.2) | 19 (0.3) | 18 (0.3) | .37 |
| Influenza vaccineb | 3135 (57.8) | 4058 (64.8) | 4236 (70.1) | <.01 |
| Antiviral therapyb | 5009 (84.6) | 6059 (87.1) | 5906 (87.5) | <.01 |
| Pneumonia | 1233 (20.7) | 1472 (21.0) | 1576 (23.2) | <.01 |
| In-Hospital death or transfer to hospiceb | 225 (3.8) | 370 (5.3) | 588 (8.7) | <.01 |
aCochran-Armitage Χ2 test for trend except for season for which a standard Χ2 test was used.
bMissing data excluded from % (non-white race: 12% missing, no association with age; Hispanic ethnicity: 24% missing, increase from 23% to 26% with age; morbid obesity: 6% missing, no association with age; influenza vaccine: 10% missing, increase from 9% to 11% with age; antiviral therapy: <1% missing, no association with age; in-hospital death or transfer to hospice: 1% missing, no association with age).