The DEL-IB item bank contains item parameters on the logistic (2PL for binary items, graded response model for categorical items) scaling metric. Parameter values are labeled “a” for discrimination parameters and “b#” for difficulty parameters, where # takes on values 1,2, or 3 and indicates the threshold number for items with 2, 3 or 4 response categories. The Stata code is an example of using gsem in Stata to obtain latent trait estimates when some/all of the item parameters are constrained. See here for an example (and discussion) of doing the sample with Mplus.
Statistical harmonization code (Stata version 16.1) to create the crosswalks and the Delirium Item Bank:
https://github.com/rnj0nes/NIDUS_Measurement_Core
Reference:
Helfand BKI, Detroyer E, Milisen K, et al. Harmonization of Four Delirium Instruments: Creating Crosswalks and the Delirium Item-Bank (DEL-IB). Am J Geriatr Psychiatry. 2022;30(3):284-294. doi:10.1016/j.jagp.2021.07.011