Abstract
PURPOSE: Unguided internet-based interventions (IBIs) have proven to be effective in reducing depressive symptoms. The primary objective of this meta-analysis was to evaluate the effect of unguided IBIs on quality of life (QoL). METHOD: We searched eligible databases via PubMed and OVID for articles published between the inception of the databases and the 1st of October 2024. For quality assessment, the RoB-2 tool was used. We included randomized controlled trials (RCTs) that examined unguided IBIs, specifically designed to reduce depressive symptoms for patients between the age of 18-65 years. A three-level random effects model was employed for analysing global QoL as well as mental and physical health related QoL and depressive symptoms. RESULTS: In total, 15 studies on 20 unique IBIs were included, comprising a total sample size of 3623 participants. Unguided IBIs significantly improved users' global QoL at the end of the intervention compared to control groups (g = 0.29, 95% CI [0.04, 0.55], p = 0.03). Mental and physical health QoL measurements did not significantly differ post intervention or 6-months follow-up. Furthermore, unguided IBIs had a small effect on depressive symptoms post intervention (g = - 0.37 (95% CI -0.62 to - 0.12, p = 0.01) but not at 6-months follow-up. CONCLUSION: The findings indicate that unguided IBIs are effective in enhancing users' global QoL by the end of the intervention and in reducing depressive symptoms. The main limitations of this study are the small sample size and concerns regarding most bias domains. Further research is needed to investigate the effect of unguided IBIs on different QoL domains. Nonetheless, this meta-analysis provides valuable insights into the potential of unguided IBIs to enhance quality of life.