Table 1.
Characteristics of Participants Randomized to Standard-Dose (SD) or High-Dose (HD) Vaccinea
| Study factors | SD | HD | P Value | ||
|---|---|---|---|---|---|
| Age | 77 ± 7.3 (65–96) | 77 ± 7.7 (65–97) | .53 | ||
| Body mass index (BMI) | 28 ± 5.1 (15–48) | 28 ± 4.6 (17–40) | .24 | ||
| Sex | Female | 204 (64.6%) | 206 (69.6%) | .22 | |
| Male | 112 (35.4%) | 90 (30.4%) | |||
| Year | 1 (2014–2015) | 53 (16.8%) | 53 (17.9%) | .95 | |
| 2 (2015–2016) | 90 (28.5%) | 85 (28.7%) | |||
| 3 (2016–2017) | 89 (28.2%) | 85 (28.7%) | |||
| 4 (2017–2018) | 84 (26.6%) | 73 (24.7%) | |||
| Site | HSNRI | 187 (59.2%) | 169 (57.1%) | .66 | |
| UCHC | 129 (40.8%) | 127 (42.9%) | |||
| CMV serostatus | Negative | 166 (52.5%) | 121 (40.9%) | .005 | |
| Positive | 150 (47.5%) | 175 (59.1%) | |||
| Laboratory-confirmed flu | Negative | 296 (93.7%) | 286 (96.6%) | .13 | |
| Positive | 20 (6.3%) | 10 (3.4%) | |||
| Frailty index | Continuous variable | 0.10 ± 0.07 (0–0.41) | 0.11 ± 0.07 (0–0.39) | .12 | |
| Categorical | Robust | 166 (52.5%) | 140 (47.3%) | .32 | |
| Prefrail | 120 (38%) | 130 (43.9%) | |||
| Frail | 29 (9.2%) | 25 (8.4%) | |||
| Missing | 1 (0.3%) | 1 (0.3%) |
Abbreviations: CMV, cytomegalovirus; HSNRI, Health Sciences North Research Institute; UCHC, University of Connecticut Health Center.
aAge, BMI, and frailty index (continuous) are presented as mean ± standard deviation (minimum-maximum), and differences between SD and HD are estimated by t test. The remaining categorical variables are presented as count (frequency), and differences between SD and HD are estimated by χ 2 test.