Equivalence of Paper and Smartphone Versions of the Beck Depression Inventory-II.

The Beck Depression Inventory-II (BDI-II) is a widely used patient-reported outcome (PRO) tool designed to screen for depressive symptoms and assess their severity. In recent years, with advancements in digital technology, the BDI-II has been adapted for use as an electronic PRO (ePRO) tool. However, to the best of our knowledge, the reliability of the smartphone version of the BDI-II has not been thoroughly investigated. This study aimed to assess the equivalence of the traditional paper and smartphone versions of the BDI-II. This study employed a randomized crossover design with adults ( = 100) from the Gunma Prefecture, Japan. Participants completed both the paper and smartphone versions of the BDI-II at 1-week intervals. The equivalence between the two versions was evaluated using the intraclass correlation coefficient (ICC). Additionally, Cronbach's alpha and McDonald's omega were calculated for both versions. The mean age of the participants was 19.78 years (SD = 0.94, 10% male). The ICC between the paper and smartphone versions of the BDI-II was 0.81 (95% CI 0.74-0.87). Cronbach's alpha was 0.88 (95% CI 0.84-0.91) for the paper version and 0.88 (95% CI 0.84-0.91) for the smartphone version. McDonald's omega was 0.88 (95% CI 0.81-0.95) for the paper version and 0.89 (95% CI 0.85-0.93) for the smartphone version. The BDI-II is suitable for use in its smartphone version, and the smartphone version of the BDI-II is a valuable addition to the mental healthcare professional's toolkit.