Wood D, Kosa K, Brown D, Ehrlich OG, Higgins PDR, Heller C. Preferences of adult patients with inflammatory bowel disease for attributes of clinical trials: evidence from a choice-based conjoint analysis. Crohns Colitis 360. 2020 Jan;2(1). doi: 10.1093/crocol/otz048
Williams VSL. The "unbiased" anchor: bridging the gap between DIF and item bias. Appl Meas Educ. 1997;10(3):253-67. doi: 10.1207/s15324818ame1003_4