Development of the web-based Spanish and Catalan versions of the Euroqol 5D-Y (EQ-5D-Y) and comparison of results with the paper version. - Robles N; Rajmil L; Rodriguez-Arjona D; Azuara M; Codina F; Raat H; Ravens-Sieberer U; Herdman M (Health and quality of life outcomes, 2015)