Hi,
I am in the process of developing my DCE pilot. This project aims to determine healthcare provider preferences regarding Atrial Fibrillation screening. I have 3 alternatives (optA, optB, and opt-out) with 5 attributes (4 X 3 levels and 1 X 2 levels). I am considering an unlabelled design and I want to include the "opt-out" to mean that Participants don’t prefer the options presented and are not necessarily against AF screening. I want to employ a dual response approach where where respondents were first given three options, ‘A’, ‘B’ and ‘neither’ (unconditional response). If they selected ‘neither,’ they were presented with a forced choice between ‘A’ and ‘B’ (conditional response). However, I've been struggling to get the opt-out option on my survey. Can you please help? Please see the code below.
Design
;alts = optA*, optB*, optout
;rows = 21
;block = 3
;eff = (mnl,d)
;cond:
if (optA.screening = 1, optA.frequency =[2]),
if (optB.screening = 1, optB.frequency =[2])
;model:
U(optA)
= b1.dummy[0.001 | 0.002] * screening device[1, 2, 0]
+ b2.dummy[0.001 | 0.002] * frequency [1, 2,0]
+ b3.dummy[0.001 | 0.002] * population [1, 2, 0]
+ b4.dummy[-0.001] * incentives [1, 0]
+ b5.dummy[0.001 | 0.002] * costs [1, 2, 0]
/
U(optB)
= b1 * screening device
+ b2 * frequency
+ b3 * population
+ b4 * incentives
+ b5 * costs
$
Thank you!