Validation and optimization of the Japanese version of the Adult Executive Functioning Inventory

Background Executive function (EF) is an umbrella term used to describe higher-order cognitive processes. Among the test batteries for EF, the Adult Executive Functioning Inventory (ADEXI) is prominent because of several advantages: it is brief, focuses on the core concept of EF, and does not include hard-to-understand general expressions and/or things that are connected but not directly linked to EFs. Aims To translate the ADEXI into Japanese and reduce the number of items required for optimization. The validation was performed using external self-reporting and laboratory task measurements. Methods A Japanese version of the ADEXI (J-ADEXI) was created through a regular translation procedure and tested using confirmatory factor analysis (CFA). We also conducted a Mokken scaling analysis (MSA) to reduce the number of J-ADEXI items and correlational analyses with external surveys and laboratory tasks. Results Although both the original model with 14 items and new the reduced model with 12 items have adequate reliability and validity, the latter was better in terms of model fit. Through discussion, we determined that J-ADEXI includes all 14 items and allows the user to choose a scoring model (i.e., 12 or 14 items model). Conclusions The J-ADEXI could briefly assess EF with adequate psychometric properties, and this study may also provide clues towards the optimization of the original and/or other language versions of the ADEXI.