Table 4.

Multivariate, multinomial backward stepwise logistic regression model for different stages of decision making about getting the COVID-19 booster vaccine, represented by PAPM stage, displaying adjusted relative risk ratios and 95 % CIs (N = 1,637).

	Decided to have the booster vaccine (n = 1,300) vs
	Unengaged (n = 106)		Undecided (n = 231)
First vaccine Oxford/AstraZeneca (vs Pfizer/BioNTech)	1.461	[0.840,2.542]	1.638*	[1.085,2.472]
Previous COVID-19 vaccine: Overall experience	0.574**	[0.391,0.843]	0.692*	[0.516,0.928]
Booster vaccine knowledge	0.384***	[0.275,0.537]	0.510***	[0.391,0.665]
Booster vaccine attitudes	0.689	[0.415,1.144]	0.284***	[0.193,0.418]
Subjective norms	0.556**	[0.373,0.829]	0.750	[0.550,1.022]
Anticipated regret	0.799*	[0.662,0.966]	0.843*	[0.727,0.977]
Perceived susceptibility: believe my immune system is strong enough to protect me against COVID-19	1.927***	[1.472,2.522]	1.383***	[1.142,1.676]
White British (vs not White British)	0.533	[0.262,1.082]	0.518*	[0.292,0.920]
Currently employed (vs not employed)	2.508***	[1.565,4.020]	1.295	[0.912,1.837]
Household income less than £30,000 (vs more than £30,000)	1.644*	[1.037,2.605]	1.380	[0.979,1.944]
Education
- No qualification	(reference)		(reference)
- High school qualification	0.363**	[0.177,0.743]	1.470	[0.741,2.915]
- University diploma/degree	0.406*	[0.182,0.906]	1.138	[0.537,2.414]
- Other qualification	0.365*	[0.162,0.824]	1.337	[0.639,2.797]
Live in East Midlands (vs London)	0.453	[0.194,1.060]	0.362**	[0.183,0.715]

Note. PAPM = precaution adoption process model. * p < 0.05, ^**p < 0.01, ^***p < 0.001. pseudo R² = 0.249.