Table 2.

Regression coefficient estimates for the preferred vaccine and vaccination attributes, Narok South District, Kenya, 2006.

Attribute	Coefficient estimate	95% CI of coefficient estimates	p
Intercept	1.5249	1.3963 to 1.6535	<0.0001
Greater than 2 h stability	0.0567	−0.0198 to 0.1332	0.1469
100% safety	0.8256	0.7469 to 0.9043	<0.0001
Inclusion of pH indicator in vaccine	0.9507	0.8709 to 1.0305	<0.0001
Government administration of vaccine	0.2315	0.1549 to 0.3081	<0.0001
Annual vaccination	0.0514	−0.0251 to 0.1279	0.1879
Elective vaccination	0.0542	−0.0223 to 0.1307	0.1653
Price (linear)	−0.0102	−0.0119 to −0.0085	<0.0001

The coefficient estimate for the alternate attribute (e.g. less than 2 h stability) was the negative of that presented in this table. Price was given linearity to allow the use of one price coefficient estimate for calculation of WTP for each attribute as −β_j/β_p where β_j is the coefficient estimate for a vaccine of vaccination attribute and β_p is the coefficient estimate for price.