scholarly journals Addendum to the Acknowledgments: Stepwise-Hierarchical Pooled Analysis for Synergistic Interpretation of Meta-analyses Involving Randomized and Observational Studies: Methodology Development

10.2196/33534 ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. e33534
Author(s):  
In-Soo Shin ◽  
Chai Hong Rim
Keyword(s):  
Observational Studies ◽  
Pooled Analysis ◽  
Methodology Development ◽  
Meta Analyses

Addendum to the Acknowledgements: Stepwise-Hierarchical Pooled Analysis for Synergistic Interpretation of Meta-analyses Involving Randomized and Observational Studies: Methodology Development (Preprint)

2021 ◽  
Author(s):  
In-Soo Shin ◽  
Chai Hong Rim
Keyword(s):  
Effect Size ◽  
Observational Studies ◽  
Statistical Significance ◽  
Pooled Analysis ◽  
Analysis Method ◽  
Methodology Development ◽  
True Effect ◽  
Randomized Studies ◽  
Logical Method ◽  
Meta Analyses

UNSTRUCTURED The necessity of including observational studies in meta-analyses has been discussed in the literature, but a synergistic analysis method for combining randomized and observational studies has not been reported. Observational studies differ in validity depending on the degree of the confounders’ influence. Combining interpretations may be challenging, especially if the statistical directions are similar but the magnitude of the pooled results are different between randomized and observational studies (the ”gray zone”). To overcome these hindrances, in this study, we aim to introduce a logical method for clinical interpretation of randomized and observational studies. We designed a stepwise-hierarchical pooled analysis method to analyze both distribution trends and individual pooled results by dividing the included studies into at least three stages (eg, all studies, balanced studies, and randomized studies). According to the model, the validity of a hypothesis is mostly based on the pooled results of randomized studies (the highest stage). Ascending patterns in which effect size and statistical significance increase gradually with stage strengthen the validity of the hypothesis; in this case, the effect size of the observational studies is lower than that of the true effect (eg, because of the uncontrolled effect of negative confounders). Descending patterns in which decreasing effect size and statistical significance gradually weaken the validity of the hypothesis suggest that the effect size and statistical significance of the observational studies is larger than the true effect (eg, because of researchers’ bias). We recommend using the stepwise-hierarchical pooled analysis approach for meta-analyses involving randomized and observational studies.

scholarly journals Stepwise-hierarchical pooled analysis: a synergistic interpretation of meta-analysis including randomized and observational studies: A methodologic study (Preprint)

2021 ◽  
Author(s):  
In-Soo Shin ◽  
Chai Hong Rim
Keyword(s):  
Effect Size ◽  
Observational Studies ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Pooled Analysis ◽  
Grey Zone ◽  
True Effect ◽  
Logical Method ◽  
Three Stages ◽  
Meta Analyses

BACKGROUND The necessity of meta-analyses including observational studies has been discussed in the literature, but a synergistic analysis method combining randomised and observational studies has not been reported. OBJECTIVE This study introduces a logical method for clinical interpretation. METHODS Observational studies differ in validity depending on the degree of the confounders’ influence. Combining interpretations might be challenging, especially if the statistical directions are similar but the magnitude of the pooled results are different, between randomised and observational studies (grey zone). We designed a stepwise-hierarchical pooled analysis, a method of analysing distribution trends as well as individual pooled results by dividing included studies into at least three stages (e.g. all studies, balanced studies, and randomised studies), to overcome such hindrances. RESULTS According to the model, the validity of hypothesis are mostly based on the pooled results of randomised studies (the highest stage). In addition, ascending patterns where effect size and statistical significance increase gradually with stage, strengthen the validity of the hypothesis; in this case, the effect size of observational studies is lower than that of the true effect (e.g. because of uncontrolled effect of negative confounders). Descending patterns where decreasing effect size and statistical significance gradually weaken the validity of the hypothesis suggest that the effect size and statistical significance of observational studies is larger than the true effect (e.g. because of researchers’ bias). These are described in more detail in the main text as four descriptive patterns. CONCLUSIONS We recommend using the stepwise-hierarchical pooled analysis for meta-analyses involving randomised and observational studies. CLINICALTRIAL NA

scholarly journals Validity of observational evidence on putative risk and protective factors: appraisal of 3744 meta-analyses on 57 topics

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Perrine Janiaud ◽  
Arnav Agarwal ◽  
Ioanna Tzoulaki ◽  
Evropi Theodoratou ◽  
Konstantinos K. Tsilidis ◽  
...  
Keyword(s):  
Protective Factors ◽  
Observational Studies ◽  
Prediction Interval ◽  
Statistical Significance ◽  
Median Number ◽  
Small Study ◽  
Study Heterogeneity ◽  
Large Heterogeneity ◽  
Meta Analyses ◽  
No Gold Standard

Abstract Background The validity of observational studies and their meta-analyses is contested. Here, we aimed to appraise thousands of meta-analyses of observational studies using a pre-specified set of quantitative criteria that assess the significance, amount, consistency, and bias of the evidence. We also aimed to compare results from meta-analyses of observational studies against meta-analyses of randomized controlled trials (RCTs) and Mendelian randomization (MR) studies. Methods We retrieved from PubMed (last update, November 19, 2020) umbrella reviews including meta-analyses of observational studies assessing putative risk or protective factors, regardless of the nature of the exposure and health outcome. We extracted information on 7 quantitative criteria that reflect the level of statistical support, the amount of data, the consistency across different studies, and hints pointing to potential bias. These criteria were level of statistical significance (pre-categorized according to 10−6, 0.001, and 0.05 p-value thresholds), sample size, statistical significance for the largest study, 95% prediction intervals, between-study heterogeneity, and the results of tests for small study effects and for excess significance. Results 3744 associations (in 57 umbrella reviews) assessed by a median number of 7 (interquartile range 4 to 11) observational studies were eligible. Most associations were statistically significant at P < 0.05 (61.1%, 2289/3744). Only 2.6% of associations had P < 10−6, ≥1000 cases (or ≥20,000 participants for continuous factors), P < 0.05 in the largest study, 95% prediction interval excluding the null, and no large between-study heterogeneity, small study effects, or excess significance. Across the 57 topics, large heterogeneity was observed in the proportion of associations fulfilling various quantitative criteria. The quantitative criteria were mostly independent from one another. Across 62 associations assessed in both RCTs and in observational studies, 37.1% had effect estimates in opposite directions and 43.5% had effect estimates differing beyond chance in the two designs. Across 94 comparisons assessed in both MR and observational studies, such discrepancies occurred in 30.8% and 54.7%, respectively. Conclusions Acknowledging that no gold-standard exists to judge whether an observational association is genuine, statistically significant results are common in observational studies, but they are rarely convincing or corroborated by randomized evidence.

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.

Arthrodesis of First Metatarsophalangeal Joint by Plate and Screws for Treatment of Hallux Rigidus (Systematic Review and Meta-Analysis)

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ossama Abdelraoof El Shazly ◽  
Mohamed Mokhtar Abdellah ◽  
Mostafa Abdelnabee Abouzaid
Keyword(s):  
Systematic Review ◽  
Observational Studies ◽  
Plate Fixation ◽  
Meta Analysis ◽  
Metatarsophalangeal Joint ◽  
Hallux Rigidus ◽  
Superficial Infection ◽  
First Metatarsophalangeal Joint ◽  
Non Union ◽  
Meta Analyses

Abstract Background With continued loss of dorsiflexion of the 1st MTP, degenerative changes occur within the joint with severe restriction of movement and increase in pain, which leads to the condition known as hallux rigidus. The amount of dorsiflexion may be reduced to 0-10 degrees with pain on both active and passive motion. Objectives Systematically reviewing available evidence from published articles to assess the effectiveness of arthrodesis of first metatarsophalangeal joint by plate and screws in hallux rigidus. The assessment also would encompass safety, side effects, and complications of this mode of treatment. Materials and Methods We performed this systematic review and meta-analysis in accordance to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) statement. PRISMA and MOOSE are reporting checklists for Authors, Editors, and Reviewers of Meta-analyses of interventional and observational studies. According to International committee of medical journal association (ICJME), reviewers must report their findings according to each of the items listed in those checklists. Results Previous results for arthrodesis have been favourable with a union rate of almost 96%. In the present systematic review and meta-analysis, the overall effect estimates showed that the union rates after plate and screw arthrodesis for 1st MTPJ was 96.2% (95% CI 94 – 98.4%). In addition, the overall effect estimates showed that the non-union rates after plate and screw arthrodesis for 1st MTPJ was 4.2% (95% CI 2.4 – 6.1%). Moreover, the overall effect estimates showed that the satisfaction rates after plate and screw arthrodesis for 1st MTPJ was 94.5% (95% CI 90 – 99%). In the present study, the overall effect estimates showed that the overall complications rate after plate and screw arthrodesis for 1st MTPJ was 7.2% (95% CI 2.5 – 12%). The overall effect estimates showed that the malunion rates after plate and screw arthrodesis for 1st MTPJ was 2.7% (95% CI 0 – 6.4%). Additionally, the overall effect estimates showed that the hardware removal and superficial infection rates after plate and screw arthrodesis for 1st MTPJ were 2% and 2.9%, respectively. Conclusion Our analysis showed that plate and screws fixation is effective techniques that can be used for first MTPJ arthrodesis in patients with hallux rigidus. We found that the screw and plate fixation has a significantly lower rate of nonunion compared with the screw alone, as reported by the literature. However, owing to the small group sizes and methodologic shortcomings, we were unable to identify the clinically superior fixation technique for first MTPJ arthrodesis arthrodesis.

scholarly journals Relationships between intensity, duration, cumulative dose, and timing of smoking with age at menopause: A pooled analysis of individual data from 17 observational studies

PLoS Medicine ◽  
2018 ◽  
Vol 15 (11) ◽  
pp. e1002704 ◽  
Author(s):  
Dongshan Zhu ◽  
Hsin-Fang Chung ◽  
Nirmala Pandeya ◽  
Annette J. Dobson ◽  
Janet E. Cade ◽  
...  
Keyword(s):  
Cumulative Dose ◽  
Observational Studies ◽  
Pooled Analysis ◽  
Individual Data ◽  
Age At Menopause

scholarly journals Reliability of recommended non-invasive chairside screening tests for diabetes-related peripheral neuropathy: a systematic review with meta-analyses

2021 ◽  
Vol 9 (2) ◽  
pp. e002528
Author(s):  
Ally McIllhatton ◽  
Sean Lanting ◽  
David Lambkin ◽  
Lucy Leigh ◽  
Sarah Casey ◽  
...  
Keyword(s):  
Systematic Review ◽  
Peripheral Neuropathy ◽  
Tuning Fork ◽  
Pooled Analysis ◽  
Screening Tests ◽  
Cochrane Library ◽  
Quality Appraisal ◽  
Perception Threshold ◽  
Rater Reliability ◽  
Meta Analyses

The objective is to determine, by systematic review, the reliability of testing methods for diagnosis of diabetes-related peripheral neuropathy (DPN) as recommended by the most recent guidelines from the International Diabetes Foundation, International Working Group on the Diabetic Foot and American Diabetes Association. Electronic searches of Cochrane Library, EBSCO Megafile Ultimate and EMBASE were performed to May 2021. Articles were included if they reported on the reliability of recommended chairside tests in diabetes cohorts. Quality appraisal was performed using a Quality Appraisal of Reliability Studies checklist and where possible, meta-analyses, with reliability reported as estimated Cohen’s kappa (95% CI). Seventeen studies were eligible for inclusion. Pooled analysis found acceptable inter-rater reliability of vibration perception threshold (VPT) (κ=0.61 (0.50 to 0.73)) and ankle reflex testing (κ=0.60 (0.55 to 0.64)), but weak inter-rater reliability for pinprick (κ=0.45 (0.22 to 0.69)) and 128 Hz tuning fork (κ=0.42 (0.15 to 0.70)), though intra-rater reliability of the 128 Hz tuning fork was moderate (κ=0.54 (0.37 to 0.73)). Inter-rater reliability of the four-site monofilament was acceptable (κ=0.61 (0.45 to 0.77)). These results support the clinical use of VPT, ankle reflexes and four-site monofilament for screening and ongoing monitoring of DPN as recommended by the latest guidelines. The reliability of temperature perception, pinprick, proprioception, three-site monofilament and Ipswich touch test when performed in people with diabetes remains unclear.

Sign in / Sign up

Export Citation Format

Share Document