Table 3.

Factors Associated with Influenza Vaccination.

	Odds Ratio (95% CI)a
Factor	2019–2021	2019–2020	2020–21
COVID-19 pandemic
No	1 [Reference]
Yes	1.23 (1.23–1.24)
Demographic characteristics
Sex
Male	1 [Reference]	1 [Reference]	1 [Reference]
Female	1.14 (1.14–1.15)	1.16 (1.15–1.16)	1.13 (1.12–1.13)
Race
White	1 [Reference]	1 [Reference]	1 [Reference]
Asian	1.07 (1.06–1.07)	0.96 (0.95–0.97)	1.17 (1.16–1.18)
Black	0.92 (0.92–0.93)	0.90 (0.90–0.91)	0.94 (0.93–0.95)
Hispanic	0.86 (0.86–0.87)	0.80 (0.79–0.80)	0.93 (0.92–0.93)
Age in 2018
18–24	1 [Reference]	1 [Reference]	1 [Reference]
25–34	1.35 (1.33–1.36)	1.42 (1.40–1.44)	1.29 (1.28–1.31)
35–44	1.50 (1.49–1.52)	1.46 (1.44–1.48)	1.55 (1.53–1.57)
45–54	1.76 (1.75–1.78)	1.63 (1.61–1.65)	1.89 (1.87–1.91)
55–64	2.50 (2.48–2.52)	2.35 (2.32–2.38)	2.65 (2.62–2.69)
≥65	3.22 (3.19–3.24)	3.19 (3.16–3.23)	3.24 (3.20–3.27)
Income
$100 K+	1 [Reference]	1 [Reference]	1 [Reference]
$75–$99 K	0.92 (0.91–0.92)	0.94 (0.93–0.95)	0.90 (0.89–0.90)
$60–$74 K	0.88 (0.87–0.88)	0.90 (0.89–0.91)	0.86 (0.85–0.86)
$50–$59 K	0.84 (0.84–0.85)	0.87 (0.86–0.88)	0.82 (0.81–0.83)
$40–$49 K	0.81 (0.80–0.81)	0.84 (0.83–0.85)	0.78 (0.77–0.79)
<$40 K	0.78 (0.78–0.78)	0.82 (0.82–0.83)	0.74 (0.74–0.75)
Education
Bachelor Degree Plus	1 [Reference]	1 [Reference]	1 [Reference]
Less than Bachelor Degree	0.80 (0.80–0.80)	0.87 (0.86–0.87)	0.75 (0.74–0.75)
High school diploma	0.75 (0.75–0.76)	0.85 (0.85–0.86)	0.67 (0.67–0.68)
Less than 12th grade	0.71 (0.69–0.73)	0.80 (0.78–0.83)	0.64 (0.62–0.66)
Medical history
Diagnosed with influenza last flu season
No	1 [Reference]	1 [Reference]	1 [Reference]
Yes	1.52 (1.50–1.54)	1.66 (1.63–1.70)	1.40 (1.38–1.43)
Received influenza vaccine last flu season
No	1 [Reference]	1 [Reference]	1 [Reference]
Yes	18.56 (18.50–18.62)	21.65 (21.55–21.75)	16.08 (16.01–16.15)

Abbreviation: CI = confidence interval.

^aMultivariable analysis adjusted for demographic characteristics and medical histories. Specifications are presented in Appendix C.