Holidaily RCT

During vacations indicators of mental health improve, especially regarding the sense of being away from the stressful work situation. It is assumed that low levels of work-related rumination are a prerequisite for successful recovery, both during vacations and during daily working hours. Although employees usually manage during vacation to being mentally away from work-related stress, the benefits for their mental health are short-lived. A mobile application was developed to investigate the question of whether vacation could be a good opportunity to acquire skills that promote a low level of work-related rumination even in everyday working life after vacation. In a randomised-controlled trial, the low threshold, gamified, mobile intervention Holidaily was examined to determine whether it could sustain the beneficial effects of vacationing compared to waitlist controls on work-related rumination, the primary outcome. It was assessed two weeks before vacation and two weeks after returning to work, before controls got access to the intervention. Due to the novelty of the research a wide range of further, yet exploratory outcomes were measured. A total of 190 workers from the general working population were randomised to either the intervention (n = 91) or a waitlist control group (n = 99). ANCOVA adhering to the Intention-to-treat principle indicated that the intervention group showed significantly lower levels of work-related rumination than the controls at two weeks post-vacation (p < 0.001, d = 0.67 [0.38–0.96]). At this time, levels of work-related rumination were still reduced by 22.2% in the intervention group, while controls showed a reduction of 6.9% compared to baseline levels two weeks before vacation. The reduction remained for up to four weeks among app users (26.1%). Study-completer and mixed-model sensitivity analyses confirmed these findings. Considering multiple testing for exploratory outcomes, no further effects were observed. This is the first randomised-controlled trial suggesting that the rapid fade-out of mental health benefits of vacations is not a law of nature. Especially it seems possible to improve workers skills in reducing their levels work-related rumination, an important transdiagnostic factor for public mental health promotion.