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

Background: 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. Methods: This study employed a randomized crossover design with adults (n = 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_agreement). Additionally, Cronbach's alpha and McDonald's omega were calculated for both versions. Results: The mean age of the participants was 19.78 years (SD = 0.94, 10% male). The ICC_agreement 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. Conclusions: 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.