Is dosage of a meditation app associated with changes in psychological distress? It depends on how you ask.

Despite growing popularity, associations between dosage and outcomes in meditation app interventions have not been established. We examined this relationship using a range of operationalizations of dosage (e.g., minutes of use, days of use, number and type of activities completed) and strategies for modeling outcomes (e.g., ordinary least squares regression, multilevel modeling, latent class analysis). We used data from a recently completed randomized controlled trial testing a meditation app (=662; 80.4% with elevated depression/anxiety) which included psychological distress as its preregistered primary outcome. Across 41 models, whether or not an association was detected as well as the shape and direction of this association varied. Although several models indicated that higher dosage was associated with larger decreases in psychological distress, many models failed to show this relationship and some even showed the opposite. These results may have implications for optimizing and studying dosage in meditation apps and for open science practices.