Internet-based and mobile-supported stress management as a universal prevention approach – Effectiveness and moderators from a large pragmatic randomized-controlled trial (Preprint)
UNSTRUCTURED Background: Emerging evidence indicates the effectiveness of Internet-based mobile supported stress management (iSMIs) in highly stressed employees. It is yet unclear, however, whether iSMIs are also effective without a preselection process in a universal prevention approach which more closely resembles routine occupational health care. Moreover, evidence for whom iSMIs might be suitable and for whom not is scarce. The present study aims to evaluate the iSMI GET.ON Stress without baseline inclusion criteria and examine moderators of intervention effects. Methods: 396 employees were randomly assigned to the intervention condition (IC) or the six-month waiting list control condition (WLC). The iSMI consisted of seven sessions and one booster session with and offered no therapeutic guidance. Self-report data were assessed at baseline, seven weeks, and at six months following randomization. The primary outcome was perceived stress (PSS-10). Several a priori defined moderators were explored as potential effect modifiers. Results: Participants of the IC reported significantly lower perceived stress at post-treatment (d=0.71) and six-month follow-up (d=0.61) compared to the WLC. Significant differences with medium to large effect sizes were found for all mental health and most work-related outcomes. Resilience, agreeableness, psychological strain and self-regulation moderated intervention effects. Discussion: This study indicates that iSMIs can be effective in a broad range of employees with no need for pre-selection to achieve substantial effects. The subgroups that might not profit all had extreme values on the respective measures and represented only a very small proportion of the investigated sample, indicating a broad applicability of GET.ON Stress.