1 Department of Educational & Counselling Psychology, McGill University, 3700 McTavish, Montreal, Quebec H3A 1Y9, Canada.
2 Campus Wellness and Support Services, Concordia University, 1550 Maisonneuve, Montreal, Quebec H3G 1M8, Canada.

University students are reporting high levels of stress that interfere with their academic performance and daily functioning. In response, higher education institutions have increasingly implemented digital, self-guided stress management resources to provide students with accessible mental health support. While these interventions show promise for improving student wellness, there is a significant gap in our understanding of how students use the strategies taught as part of these resources. This systematic review therefore examined if and how adherence (i.e., strategy use) has been measured in the context of digital self-guided stress management interventions, as well as its associations with stress and other wellness outcomes. Of the 40 studies that met eligibility criteria for the present review, 33 measured adherence (82.5 %). Specifically, nine studies measured frequency (27.2 %), eight measured completion rates (24.2 %), two measured duration (6.1 %), 12 used a combination of these approaches (36.4 %), and two (6.1 %) did not specify which approach was used. Surprisingly, although the majority of studies collected data on adherence, the associations between adherence and stress or other wellness outcomes were scarcely examined. Across studies, adherence was measured using digital analytics and/or self-report; however, barriers were identified in using these methods, including technological issues and challenges in measurement accuracy. Quality assessments revealed a moderate risk of bias. Future research should explore different approaches to enhance adherence measurement accuracy and further examine the link between adherence and wellness outcomes to determine the optimal dose of strategy use for enhancing wellness among university students.