Table 3. Final model multivariable linear regression model showing factors associated with the willingness to pay for COVID-19 vaccination (n=1,188).

Variable		Unstandardized coefficients			US dollar ($) estimate			p-value
	B	95% CI of B		SE	Mean	95% CI
		Lower	Upper			Lower	Upper
Country (Pakistan)
Brazil	0.022	-0.259	0.304	0.143	1.746	-0.284	3.775	0.878
Chile	0.060	-0.218	0.338	0.142	1.813	-0.216	3.843	0.671
Egypt	-0.263	-0.565	0.039	0.154	1.313	-0.717	3.342	0.087
India	-0.168	-0.400	0.064	0.118	1.443	-0.586	3.473	0.155
Iran	-0.060	-0.335	0.215	0.140	1.608	-0.421	3.637	0.669
Nigeria	0.050	-0.215	0.315	0.135	1.795	-0.234	3.824	0.711
Bangladesh	-0.301	-0.573	-0.029	0.139	1.264	-0.765	3.293	0.030
Sudan	-0.549	-0.822	-0.276	0.139	0.986	-1.043	3.016	<0.001
Tunisia	-0.509	-0.791	-0.226	0.144	1.027	-1.003	3.056	<0.001
Monthly household income (USD) (<500)
500-999	0.153	-0.026	0.321	0.086	1.990	-0.039	4.019	0.760
1,000-1,999	0.224	0.281	0.420	0.100	2.137	0.107	4.166	0.005
2,000-2,999	-0.261	-0.012	-0.036	0.115	1.315	-0.714	3.344	0.919
3,000-4,999	0.373	0.173	0.615	0.123	2.480	0.451	4.509	0.159
5,000-7,999	0.754	0.175	1.016	0.133	3.628	1.599	5.658	0.191
≥8,000	0.260	0.325	0.522	0.134	2.214	0.185	4.243	0.015
Healthcare-related job (No)
Yes	0.153	0.021	0.285	0.067	1.990	-0.039	4.019	0.024
Have pulmonary disease (No)
Yes	0.224	-0.044	0.492	0.137	2.137	0.107	4.166	0.101
Do not know	-0.261	-0.397	-0.126	0.069	1.315	-0.714	3.344	<0.001
All routine vaccines recommended by the healthcare workers are beneficial (Disagree or strongly disagree)
Neither agree nor disagree	0.373	-0.011	0.758	0.196	2.480	0.451	4.509	0.057
Agree or strongly agree	0.754	0.400	1.108	0.180	3.628	1.599	5.658	<0.001
Having flu vaccination during the past 12 months (No)
Yes	0.260	0.105	0.415	0.079	2.214	0.185	4.243	0.001
MSE	1.070
F-value (p<0.001)	7.671
R2	0.121

CI: Confidence interval; MSE: Mean squared error