“…As suggested in the relevant research literature (Borenstein, Hedges, Higgins, & Rothstein, 2009), sample and study characteristics, such as sample age, gender, population (students, the mentally or physically ill, media users, and general population), and random versus non-random samples are included, as well as year of publication. Recent literature (e.g., Trepte et al, 2017) argues that the cultural context could be important in the perception of the social gratification obtained from OMU. As such, the nationality of participants is included as a potential moderator.…”