Purpose: This study aimed to systematically evaluate the effectiveness of DHIs in improving cognitive function among older adults and to explore whether participant characteristics moderate these effects.

Methods: An umbrella review and meta-meta-analysis were conducted in accordance with PRISMA guidelines, with the study pre-registered on the PROSPERO database (CRD420251003146). The eligibility criteria were clearly defined using the PICOS framework. A comprehensive literature search was performed across multiple databases including Web of Science, PubMed, CINAHL, Scopus, and the Cochrane Library. Methodological quality was assessed with the AMSTAR 2 tool and the corrected covered area (CCA) was calculated to evaluate overlap between studies, ensuring the reliability of the meta-meta-analysis.

Results: A total of 31 systematic reviews and meta-analyses involving 31,093 older adults were included. The findings indicated that DHIs had a significant positive impact on global cognitive function (SMD = 0.50, 95% CI: 0.40-0.60, p < 0.001). The positive effects were also found across specific cognitive domains, including attention (SMD = 0.41), memory (SMD = 0.37), executive function (SMD = 0.35), and processing speed (SMD = 0.21). Furthermore, the subgroup analyses demonstrated that individuals with MCI and dementia experienced greater cognitive improvements from the interventions.

Conclusion: The results suggest that DHIs hold substantial potential for enhancing cognitive function in the elderly population. By providing timely and personalized interventions, they can effectively improve cognitive outcomes, offering practical utility in clinical settings, and informing the development of policies aimed at expanding access to cognitive health services.