Box 1.

Sample discrete choice experiment task

Treatment 1	Treatment 2	No treatment
Treatment will result in 25 pregnancies in 100 couples	Treatment will result in 10 pregnancies in 100 couples	No improved chance of pregnancy
5 women in 100 will have moderate or severe complications	2 women in 100 will have moderate or severe complications	No risk of treatment-related complications
Side effects of treatment are mild	Side effects of treatment are strong	No treatment-related side effects
You will have full involvement in decisions about your treatment	You will have no involvement in decisions about your treatment	No physician contact
You will require 5 injections per day	You will require 3 injections per day	No injections per day
Treatment will cost ££££a per cycle	Treatment will cost ££££a per cycle	No treatment-related cost
o I prefer Treatment 1	o I prefer Treatment 2	o I prefer no treatment

^a££££ was replaced with a country-specific currency symbol and cost per cycle