Table 3.
Patient Characteristics by Season
| Variable | 2011/2012 | 2012/2013 | 2013/2014 | Significancea |
|---|---|---|---|---|
| n = 698 | n = 1980 | n = 2333 | ||
| Influenza case | 167 (23.9%) | 870 (43.9%) | 775 (33.2%) | P < .001 |
| Type A | 49 (29.3%) | 815 (93.7%) | 359 (46.3%) | P < .001 |
| Type B | 118 (70.7%) | 55 (6.3%) | 416 (53.7%) | |
| Age mean (SD) | 79.2 (SD 8.1) | 79.7 (SD 8.4) | 79.3 (SD 8.4) | P = .13 |
| Sex, n (%) women | 398 (57.0%) | 1032 (52.1%) | 1231 (52.8%) | P = .08 |
| Vaccinated N (%) | 484 (69.3%) | 1320 (68.7%) | 1629 (69.8%) | P = .07 |
| Baseline frailty index, mean FI (SD) | 0.20 (SD 0.11) | 0.22 (SD 0.12) | 0.23 (SD 0.13) | P < .001 |
| Frailty at admission, mean FI (SD) | 0.26 (SD 0.13) | 0.29 (SD 0.13) | 0.28 (0.14) | P < .001 |
| Frailty at 30 days postdischarge, mean (SD) | 0.20 (0.11) | 0.22 (0.13) | 0.22 (0.13) | P < .001 |
| Deceased 30 days postdischarge, N (%) | 53 (7.6%) | 238 (12.0%) | 265 (11.4%) | P < .01 |
| Recovered, N (%) | 581 (83.2%) | 1494 (75.5%) | 1866 (80.0%) | P < .001 |
Abbreviations: FI, frailty index; SD, standard deviation.
aAnalysis of variance (continuous variables) or χ 2 (categorical variables), as appropriate. For frailty at admission N = 691 in 2011/2012, N = 1935 in 2012/2013, N = 2266 in 2013/2014. For frailty at discharge N = 645 in 2011/2012, N = 1742 in 2012/2013, and N = 2068 in 2013/2014.