Assessing the Quality of Evidence Regarding Permanently Listed Digital Health Applications (DiGAs) in Germany: A Scoping Review

Background/Objectives: Germany’s 2019 Digital Healthcare Act allows manufacturers to integrate digital health applications (DiGAs) into statutory health insurance if they demonstrate a medical benefit or patient-relevant structural or procedural improvement, substantiated by comparative studies. However, existing reviews indicate that the quality of evidence in these studies is inconsistent. Methods: A scoping review following the PRISMA-ScR guidelines was conducted using MEDLINE on 16 December 2024, via PubMed, Scopus, EMBASE, and Cochrane Library. Studies published between 2020 and 2024 assessing DiGA evaluation tools, study quality, and the strength of evidence were included, while non-DiGA studies, telemedicine research, and register-based studies were excluded. Results: Out of the 4628 publications screened, 16 met the inclusion criteria. Across the nine dimensions of evidence quality, deficits were most frequently identified in relation to validity (nine publications), transparency (seven), objectivity (six), consistency (five), and reliability (five), followed by relevance, generalizability, and accuracy (four each) and timeliness (two). Conclusions: The findings highlight substantial limitations in the quality of DiGA studies, including high dropout rates, a lack of blinding, gender imbalance, a high risk of bias, small sample sizes, and biased control-group designs. Additionally, DiGA usage durations were often shorter than recommended. Strengthening the evidence base for DiGAs requires balancing methodological rigor with the practical realities of digital health development. Sustainable integration into routine care depends on feasible evaluation pathways that enable continuous, real-world evidence generation and address the financial and operational challenges of high-quality evaluations.