Implementation Outcome Scales for Digital Mental Health (iOSDMH): Scale Development and Cross-sectional Study - Natsu Sasaki; Erika Obikane; Rajesh Vedanthan; Kotaro Imamura; Pim Cuijpers; Taichi Shimazu; Masamitsu Kamada; Norito Kawakami; Daisuke Nishi (JMIR Formative Research, 2021)