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.