Table 4.

Random parameters logit estimates (N=323)

Attribute		Preference weight	95% confidence interval
Skin sensor		0.725**	0.552	0.897
Control of the speed of injection		0.455**	0.320	0.591
Step-by-step, on-screen instructions in real time		0.304**	0.182	0.427
Injection date reminder		0.438**	0.292	0.584
Electronic log		0.497**	0.369	0.626
Large grip size		−0.181	−0.424	0.062
Out-of-pocket cost	£0	4.297**	3.472	5.122
	£15	3.571**	2.885	4.256
	£30	2.844**	2.298	3.391
	£50	1.876**	1.516	2.236
	£90	−0.061**	−0.072	−0.049
	£125	−1.755**	−2.092	−1.418
	£150	−2.965**	−3.535	−2.396
£250	−7.807**	−9.306	−6.308
Constant for standard disposable self-injection device		0.338	−0.286	0.961

Notes: All variables, with the exception of out-of-pocket cost, were dichotomous and effects-coded. We present coefficients estimates for the included features, the coefficient for excluded features is computed as the negative of it. Cost was included in the model as the interaction of continuous cost and the natural log of income. The preference weights were created using the estimated coefficient for cost. The parameters were modeled with normally distributed random parameters. An error component was included to better accommodate the opt-out bias that could be caused by the standard device alternative. **P≤0.01.