Table 4.

Factors associated with completion of primary COVID-19 vaccination series among older adults in Hong Kong (n = 440).

	OR (95% CI)	p Values	Cohen’s d	AOR (95% CI)	p-Value	Cohen’s d
Perceived impacts of incentives provided by the government on increasing one’s motivation to receive COVID-19 vaccination
Lottery for winning prizes	1.36 (1.02–1.81)	0.04	0.17	1.41 (1.05–1.90)	0.02	0.19
Visiting mainland China or other places without quarantine	1.42 (1.20–1.68)	<0.001	0.19	1.43 (1.20–1.71)	<0.001	0.20
Allowing visits to elderly homes and hospitals without COVID-19 testing	1.69 (1.34–2.11)	<0.001	0.29	1.78 (1.40–2.27)	<0.001	0.32
Entering bars or clubs	1.81 (1.13–2.90)	0.01	0.33	2.02 (1.23–3.33)	0.01	0.39
Walk-in vaccination services for older adults without prior booking	1.27 (1.05–1.55)	0.02	0.13	1.31 (1.06–1.61)	0.01	0.15
Satisfaction with COVID-19 vaccination health promotional materials (e.g., advertisements, posters, and others) produced by the government
Whether the information is easy to understand
No/uncertain	1.0			1.0
Yes	1.69 (0.93–3.06)	0.09	0.29	1.48 (0.77–2.85)	0.24	0.22
Whether the materials can address your concerns related to COVID-19 vaccination
No/uncertain	1.0			1.0
Yes	4.08 (2.67–6.23)	<0.001	0.78	4.21 (2.70–6.58)	<0.001	0.79
Whether the materials are helpful for you in making a decision on whether to receive a COVID-19 vaccine
No/uncertain	1.0			1.0
Yes	4.54 (3.00–6.85)	<0.001	0.83	4.74 (3.07–7.34)	<0.001	0.86
Perceptions related to COVID-19 vaccination
Attitude Scale	0.62 (0.56–0.68)	<0.001	−0.26	0.62 (0.55–0.69)	<0.001	−0.26
Subjective Norm Scale	0.56 (0.47–0.68)	<0.001	−0.32	0.55 (0.46–0.67)	<0.001	−0.32
Perceived behavioral control to take up COVID-19 vaccination	7.49 (2.51–22.34)	<0.001	1.11	6.77 (2.29–20.04)	0.001	1.05
Decisional Conflict Scale	2.50 (2.01–3.11)	<0.001	0.51	2.53 (2.02–3.17)	<0.001	0.51

OR—crude odds ratios; CI—confidence interval; AOR—adjusted odds ratios; odds ratios adjusted for significant background characteristics are listed in Table 3.