Table 3.

Testing of the mediating role of decision regret.

Variable	Model 1		Model 2		Model 3
	OR	95%CI	B	95%CI	OR	95%CI
Independent variable
Post-vaccination adverse reaction (No)
Yes	0.48***	0.32   0.72	1.65***	1.01   2.30	0.58**	0.38   0.87
Mediator
Decision regret					0.89***	0.85   0.92
Controlled variable
Age (<30)
30   39	1.07	0.79   1.45	−0.27	−0.79   0.24	1.04	0.76   1.41
40   49	1.55*	1.03   2.32	−0.47	−1.15   0.20	1.48	0.98   2.24
≥50	1.70	0.85   3.41	−0.05	−1.19   1.10	1.72	0.86   3.50
Sex (Male)
Female	1.61*	1.09   2.40	0.08	−0.57   0.73	1.66	1.12   2.50
Education (Senior Secondary and below)
Junior college	2.25*	1.21   4.26	−1.92***	−2.96 -0.87	1.83	0.96   3.49
Undergraduate	1.79*	1.05   3.07	−2.02***	−2.91 -1.14	1.41	0.82   2.46
Graduate	2.24*	1.14   4.44	−2.15***	−3.28 -1.03	1.76	0.89   3.54
Underlying disease (No)
Yes	0.70	0.46   1.04	−0.06	−0.73   0.61	0.69	0.45   1.03

***, P-value <.001; **, P-value <.01; *, P-value <.05. The outcome of Model 1 and 3 was WTP for the booster dose of COVID-19 vaccine (1 denotes “Yes”); the outcome of Model 2 was decision regret.

Abbreviation: OR, odds ratio; CI, confidence interval; B, standardized beta regression coefficient.