Skip to main content

Table 1 Demographic characteristics of the entire study cohort included in this study, by individual study seasons

From: Interseason waning of vaccine-induced hemagglutination inhibition antibody titers and contributing factors to pre-existing humoral immunity against influenza in community-dwelling older adults 75 years and older

Total person-seasonsa (n = 449)

2014 (n = 74)

2015 (n = 113)

2016 (n = 90)

2017 (n = 172)

Age, mean (standard deviation)

83.3 (5.3)

82.4 (5.6)

82.2 (5.6)

82.8 (5.1)

Sex (male), n (%)

30 (39.5)

51 (44.7)

40 (43.5)

69 (40.1)

Race (white), n (%)

63 (82.9)

99 (87.6)

79 (85.9)

148 (86.1)

Education, n (%)

High school

28 (36.8)

36 (31.9)

32 (34.8)

60 (34.9)

College

29 (38.2)

43 (38.0)

41 (44.6)

73 (42.4)

Graduate school

19 (25.0)

34 (30.1)

19 (20.6)

39 (22.7)

Frailty, n (%)

Non-frail

22 (32.4)

27 (27.0)

32 (38.6)

60 (37.5)

Prefrail

40 (58.8)

58 (58.0)

44 (53.0)

80 (50.0)

Frail

6 (8.8)

15 (15.0)

7 (8.4)

20 (12.5)

  1. aOut of total person-seasons, 113 subjects participated in a single season and 124 subjects participated in at least two consecutive seasons from 2014 through 2017