Strand V, Kaeley GS, Bergman MJ, Gladman DD, Coates LC, Sherif B, Hur P, Parikh B, Gilloteau I, Mease PJ. The effect of secukinumab on patient-reported outcomes in patients with active psoriatic arthritis in a randomized phase 3 trial. Lancet Rheumatol. 2022 Mar 1;4(3):e208-19.
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