scholarly journals How Credible Are Meta-Analyses of Risk Factors Based on Observational Studies for Amyotrophic Lateral Sclerosis? A New Insight from an Umbrella Review

2016 ◽  
Vol 46 (4) ◽  
pp. 271-272 ◽  
Author(s):  
Ming-Dong Wang ◽  
Julian Little
Keyword(s):  
Risk Factors ◽  
Amyotrophic Lateral Sclerosis ◽  
Observational Studies ◽  
Umbrella Review ◽  
Meta Analyses ◽  
Lateral Sclerosis

scholarly journals Environmental Risk Factors and Amyotrophic Lateral Sclerosis: An Umbrella Review and Critical Assessment of Current Evidence from Systematic Reviews and Meta-Analyses of Observational Studies

2016 ◽  
Vol 46 (2) ◽  
pp. 96-105 ◽  
Author(s):  
Lazaros Belbasis ◽  
Vanesa Bellou ◽  
Evangelos Evangelou
Keyword(s):  
Risk Factors ◽  
Amyotrophic Lateral Sclerosis ◽  
Environmental Factors ◽  
Random Effects ◽  
Systematic Reviews ◽  
Environmental Risk ◽  
Observational Studies ◽  
Environmental Risk Factors ◽  
Meta Analyses ◽  
Lateral Sclerosis

Background: The pathogenesis of amyotrophic lateral sclerosis (ALS) involves both environmental and genetic factors. Our study aimed at summarising the environmental risk factors for ALS, assessing the evidence for diverse biases, and pinpointing risk factors with high epidemiological credibility. Methods: We searched PubMed from inception to August 20, 2015, to identify systematic reviews and meta-analyses of observational studies examining associations between environmental factors and ALS. For each meta-analysis, we estimated the summary effect size by the use of random-effects and fixed-effects models, the 95% CI, the 95% prediction interval (PI), and the between-study heterogeneity. We assessed the evidence of small-study effects and excess significance bias. Results: Sixteen unique meta-analyses of different risk factors and ALS were considered. Of them, 5 were statistically significant at p < 0.001 under the random-effects model. Only one factor presented robust evidence for a convincing association. This association pertained to chronic occupational exposure to lead (random-effects OR 1.81, 95% CI 1.39-2.35). Conclusions: A small number of published meta-analyses on environmental factors and risk of ALS was identified, a phenomenon that could be attributed to the challenges in studying a rare neurological disease. More observational studies with adequate sample size and study design are needed to clarify the environmental component of ALS pathogenesis.

scholarly journals Risk Factors for Gestational Diabetes: An Umbrella Review of Meta-Analyses of Observational Studies

2018 ◽  
Author(s):  
Konstantinos Giannakou ◽  
Evangelos Evangelou ◽  
Panayiotis Yiallouros ◽  
Costas A. Christophi ◽  
Nicos Middleton ◽  
...  
Keyword(s):  
Risk Factors ◽  
Gestational Diabetes ◽  
Observational Studies ◽  
Umbrella Review ◽  
Meta Analyses

scholarly journals Risk factors for gestational diabetes: An umbrella review of meta-analyses of observational studies

PLoS ONE ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. e0215372 ◽  
Author(s):  
Konstantinos Giannakou ◽  
Evangelos Evangelou ◽  
Panayiotis Yiallouros ◽  
Costas A. Christophi ◽  
Nicos Middleton ◽  
...  
Keyword(s):  
Risk Factors ◽  
Gestational Diabetes ◽  
Observational Studies ◽  
Umbrella Review ◽  
Meta Analyses

The Dietary Inflammatory Index and Human Health: An Umbrella Review of Meta-Analyses of Observational Studies

2021 ◽  
Author(s):  
Wolfgang Marx ◽  
Nicola Veronese ◽  
Jaimon T Kelly ◽  
Lee Smith ◽  
Meghan Hockey ◽  
...  
Keyword(s):  
Chronic Disease ◽  
Health Outcomes ◽  
Observational Studies ◽  
Dietary Inflammatory Index ◽  
Credibility Assessment ◽  
Umbrella Review ◽  
Inflammatory Index ◽  
Increased Risk ◽  
Meta Analyses ◽  
Study Designs

ABSTRACT Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: statistical heterogeneity, 95% prediction intervals, evidence for small-study effect and/or excess significance bias, as well as effect sizes and P values using calculated random effects meta-analyses. In total, 15 meta-analyses reporting on 38 chronic disease-related outcomes were included, incorporating a total population of 4,360,111 subjects. Outcomes (n = 38) were examined through various study designs including case-control (n = 8), cross-sectional (n = 5), prospective (n = 5), and combination (n = 20) study designs. Adherence to a pro-inflammatory dietary pattern had a significant positive association with 27 (71%) of the included health outcomes (P value &lt; 0.05). Using the credibility assessment, Class I (Convincing) evidence was identified for myocardial infarction only, Class II (Highly suggestive) evidence was identified for increased risk of all-cause mortality, overall risk of incident cancer, and risk of incident site-specific cancers (colorectal, pancreatic, respiratory, and oral cancers) with increasing (more pro-inflammatory) DII score. Most outcomes (n = 31) presented Class III (Suggestive) or lower evidence (Weak or No association). Pro-inflammatory dietary patterns were nominally associated with an increased risk of many chronic disease outcomes. However, the strength of evidence for most outcomes was limited. Further prospective studies are required to improve the precision of the effect size.

scholarly journals Dietary Inflammatory Index and Health Outcomes: An Umbrella Review of Systematic Review and Meta-Analyses of Observational Studies

2021 ◽  
Vol 8 ◽  
Author(s):  
Fang-Hua Liu ◽  
Chuan Liu ◽  
Ting-Ting Gong ◽  
Song Gao ◽  
Hui Sun ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Colorectal Cancer ◽  
Health Outcomes ◽  
Observational Studies ◽  
Cancer Colorectal ◽  
Dietary Inflammatory Index ◽  
Umbrella Review ◽  
Inflammatory Index ◽  
Cancer Breast ◽  
Meta Analyses

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.Systematic Review Registration: CRD42021218361

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