Example of umbrella reviews

An umbrella review, also known as an overview of reviews, is a comprehensive examination that synthesizes evidence from multiple systematic reviews and meta-analyses on a particular topic. It aims to provide a high-level summary of a wide range of research findings, often addressing broader questions than those explored in individual reviews.

Medicine

The umbrella review “Physical Activity and Exercise in Mild Cognitive Impairment and Dementia: An Umbrella Review of Intervention and Observational Studies” by Demurtas et al. (2020) aimed to evaluate the impact of physical activity/exercise on cognitive and noncognitive outcomes in individuals with mild cognitive impairment and dementia. The review encompassed systematic reviews and meta-analyses of randomized controlled trials and observational studies. Participants were diagnosed with mild cognitive impairment or dementia through validated assessments, and their outcomes were compared to those who did not engage in physical activity/exercise.

The literature search, registered in PROSPERO, included major databases until December 31, 2019. Evidence certainty was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.
From 1160 initial articles, 27 systematic reviews involving 28,205 participants were included. For mild cognitive impairment, mind-body interventions and mixed physical activity showed small cognitive improvements, while resistance training had a large effect with very low certainty.

In dementia, physical activity/exercise improved cognition in Alzheimer’s and all dementia types and reduced noncognitive issues like falls and neuropsychiatric symptoms. The review concluded that while physical activity/exercise shows positive effects on cognitive and noncognitive outcomes in mild cognitive impairment and dementia, further randomized controlled trials are needed to confirm these findings.

Conclusion

Literature reviews play a crucial role in the research process. They offer valuable insights into the current state of knowledge on a topic. A well-executed literature review can be as impactful as original research by adhering to proper guidelines and maintaining high standards. It highlights the latest findings, provides a critical analysis of previous studies, and guides researchers in shaping their future investigations. Through comprehensive literature reviews, researchers gain a deeper understanding of their field, identify gaps in existing knowledge, and make informed decisions about their research direction.

References

Livingston JD, Boyd JE. Correlates and consequences of internalized stigma for people living with mental illness: a systematic review and meta-analysis. Soc Sci Med. 2010 Dec;71(12):2150-61. doi: 10.1016/j.socscimed.2010.09.030. Epub 2010 Oct 12. PMID: 21051128.

Glenton C, Colvin CJ, Carlsen B, Swartz A, Lewin S, Noyes J, Rashidian A. Barriers and facilitators to the implementation of lay health worker programmes to improve access to maternal and child health: qualitative evidence synthesis. Cochrane Database Syst Rev. 2013 Oct 8;2013(10): CD010414. doi: 10.1002/14651858.CD010414.pub2. PMID: 24101553; PMCID: PMC6396344.

AlJohani A, Karuppiah K, Al Mutairi A, Al Mutair A. Narrative Review of Infection Control Knowledge and Attitude among Healthcare Workers. J Epidemiol Glob Health. 2021 Mar;11(1):20-25. doi: 10.2991/jegh.k.201101.001. Epub 2020 Nov 9. PMID: 33605115; PMCID: PMC7958281.