Harmonization of Four Delirium Instruments: Creating Crosswalks and the Delirium Item-Bank (DEL-IB)

•In this paper, we harmonized 4 of the most commonly used instruments for delirium identification—Confusion Assessment Method (long-form and short-form), Delirium Observation Screening Scale, Delirium Rating Scale-Revised-98 (total and severity scores), and Memorial Delirium Assessment Scale.•Using modern methods in psychometrics, including item response theory, we aligned all of the instruments on the same metric, the propensity to delirium. After linking scores, we created a harmonized item bank, called the Delirium Item Bank (DEL-IB), consisting of 50 items that allowed for the creation of crosswalks, to allow scores to be translated across instruments.•Our results facilitate the comparison of studies, meta-analyses, and combining data sets.