scholarly journals Study Design Guidelines

2019 ◽  
Vol 25 (3) ◽  
pp. 165-184 ◽  
Author(s):  
A. P. Sereda ◽  
M. A. Andrianova
Keyword(s):  
Study Design ◽  
Meta Analysis ◽  
Good Reason ◽  
Case Series ◽  
Scientific Publication ◽  
Design Guidelines ◽  
Case Control Studies ◽  
Meta Analyses ◽  
Key Aspects

Complying with certain requirements or, more precisely, following the guidelines for the design of a scientific publication helps to make it not only more comprehensible for reviewers and readers, but actually enhances the quality of work. For example, even if some aspects in design logic were fulfilled but not described, other researchers doing meta-analysis may wrongly but for a good reason downgrade such publication and exclude it from the analysis. Understanding of the guidelines for study design ensures not only the proper description of the results but the initial planning of work. The CA RE guidelines were established for reporting of clinical cases, STROBE — for reporting observational studies (cohort and case-control studies), CO NSORT — for reporting randomized studies (these guidelines are often used also for other comparative and case series studies), STARD — for reporting diagnostic studies, and PRISMA — for reporting of systematic reviews and meta-analyses. The present paper describes the key aspects of those guidelines and provides templates for graphic display of study design in form of flow charts. Evidently, we should not forget that each study is unique and there is always a place for a reasonable compromise between “requirements” and the real logic of the research in place.

scholarly journals Study design guidelines

2020 ◽  
Vol 10 (3) ◽  
pp. 353-368
Author(s):  
Andrey P. Sereda ◽  
Marina A. Andrianova
Keyword(s):  
Study Design ◽  
Meta Analysis ◽  
Good Reason ◽  
Case Series ◽  
Scientific Publication ◽  
Design Guidelines ◽  
Copyright Holder ◽  
Case Control Studies ◽  
Meta Analyses ◽  
Key Aspects

Complying with certain requirements or, more precisely, following the guidelines for the design of a scientific publication helps to make it not only more comprehensible for reviewers and readers, but actually enhances the quality of work. For example, even if some aspects in design logic were fulfilled but not described, other researchers doing meta-analysis may wrongly but for a good reason downgrade such publication and exclude it from the analysis. understanding of the guidelines for study design ensures not only the proper description of the results but the initial planning of work. The CARE guidelines were established for reporting of clinical cases, STROBE for reporting observational studies (cohort and case-control studies), CONSORT for reporting randomized studies (these guidelines are often used also for other comparative and case series studies), STARD for reporting diagnostic studies, and PRISMa for reporting of systematic reviews and meta-analyses. The present paper describes the key aspects of those guidelines and provides templates for graphic display of study design in form of flow charts. evidently, we should not forget that each study is unique and there is always a place for a reasonable compromise between requirements and the real logic of the research in place. The article is the reprint published with the permission of the copyright holder. Original article: Sereda AP, Andrianova MA. Study Design Guidelines. Traumatology and Orthopedics of Russia. 2019;25(3):165-184. doi: 10.21823/2311-2905-2019-25-3-165-184

scholarly journals Reproducibility of systematic literature reviews on food, nutrition, physical activity and endometrial cancer

2008 ◽  
Vol 11 (10) ◽  
pp. 1006-1014 ◽  
Author(s):  
RL Thompson ◽  
EV Bandera ◽  
VJ Burley ◽  
JE Cade ◽  
D Forman ◽  
...  
Keyword(s):  
Physical Activity ◽  
Endometrial Cancer ◽  
Study Design ◽  
Systematic Reviews ◽  
Meta Analysis ◽  
Case Series ◽  
Case Control Studies ◽  
Food Nutrition ◽  
Search And Selection ◽  
Meta Analyses

AbstractObjectiveDespite the increasing dependence on systematic reviews to summarise the literature and to issue public health recommendations, the formal assessment of the reliability of conclusions emerging from systematic reviews has received little attention. The main goal of the present study was to evaluate whether two independent centres, in two continents, draw similar conclusions regarding the association of food, nutrition and physical activity and endometrial cancer, when provided with the same general instructions and with similar resources.DesignThe assessment of reproducibility concentrated on four main areas: (1) paper search and selection; (2) assignment of study design; (3) inclusion of ‘key’ papers; and (4) individual studies selected for meta-analysis and the summary risk estimate obtained.ResultsIn total 310 relevant papers were identified, 166 (54 %) were included by both centres. Of the remaining 144 papers, 72 (50 %) were retrieved in the searches of one centre and not the other (54 in centre A, 18 in centre B) and 72 were retrieved in both searches but regarded as relevant by only one of the centres (52 in centre A, 20 in centre B). Of papers included by both centres, 80 % were allocated the same study design. Agreement for inclusion of cohort-type and case–control studies was about 63 % compared with 50 % or less for ecological and case series studies. The agreement for inclusion of 138 ‘key’ papers was 87 %. Summary risk estimates from meta-analyses were similar.ConclusionsTransparency of process and explicit detailed procedures are necessary parts of a systematic review and crucial for the reader to interpret its findings.

scholarly journals Seizures in supratentorial meningioma: a systematic review and meta-analysis

2016 ◽  
Vol 124 (6) ◽  
pp. 1552-1561 ◽  
Author(s):  
Dario J. Englot ◽  
Stephen T. Magill ◽  
Seunggu J. Han ◽  
Edward F. Chang ◽  
Mitchel S. Berger ◽  
...  
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
Case Series ◽  
Seizure Freedom ◽  
Peritumoral Edema ◽  
Treatment And Prevention ◽  
Male Sex ◽  
Meta Analyses ◽  
Tumor Types

OBJECT Meningioma is the most common benign intracranial tumor, and patients with supratentorial meningioma frequently suffer from seizures. The rates and predictors of seizures in patients with meningioma have been significantly under-studied, even in comparison with other brain tumor types. Improved strategies for the prediction, treatment, and prevention of seizures in patients with meningioma is an important goal, because tumor-related epilepsy significantly impacts patient quality of life. METHODS The authors performed a systematic review of PubMed for manuscripts published between January 1980 and September 2014, examining rates of pre- and postoperative seizures in supratentorial meningioma, and evaluating potential predictors of seizures with separate meta-analyses. RESULTS The authors identified 39 observational case series for inclusion in the study, but no controlled trials. Preoperative seizures were observed in 29.2% of 4709 patients with supratentorial meningioma, and were significantly predicted by male sex (OR 1.74, 95% CI 1.30–2.34); an absence of headache (OR 1.77, 95% CI 1.04–3.25); peritumoral edema (OR 7.48, 95% CI 6.13–9.47); and non–skull base location (OR 1.77, 95% CI 1.04–3.25). After surgery, seizure freedom was achieved in 69.3% of 703 patients with preoperative epilepsy, and was more than twice as likely in those without peritumoral edema, although an insufficient number of studies were available for formal meta-analysis of this association. Of 1085 individuals without preoperative epilepsy who underwent resection, new postoperative seizures were seen in 12.3% of patients. No difference in the rate of new postoperative seizures was observed with or without perioperative prophylactic anticonvulsants. CONCLUSIONS Seizures are common in supratentorial meningioma, particularly in tumors associated with brain edema, and seizure freedom is a critical treatment goal. Favorable seizure control can be achieved with resection, but evidence does not support routine use of prophylactic anticonvulsants in patients without seizures. Limitations associated with systematic review and meta-analysis should be considered when interpreting these results.

Study Design and Statistics

2020 ◽  
pp. 977-1096
Author(s):  
Edward H. Livingston
Keyword(s):  
Study Design ◽  
Randomized Clinical Trials ◽  
Case Series ◽  
Cost Benefit ◽  
Case Control Studies ◽  
Double Blind ◽  
Correct Treatment ◽  
Noninferiority Trials ◽  
Correct Usage ◽  
Meta Analyses

The Study Design and Statistics chapter of the 11th edition of the AMA Manual of Style begins with a description of the parts of a scientific manuscript and the role of each part: Abstract, Introduction, Methods, Results, and Discussion. The features unique to different study types are outlined: randomized clinical trials, parallel-design double-blind trials, crossover trials, equivalence and noninferiority trials, cluster trials, observational studies, cohort studies, case-control studies, case series, comparative effectiveness research, meta-analyses, cost-effectiveness/cost-benefit analyses, quality improvement studies, and survey studies. Because correct treatment depends on accurate diagnosis, attention is given to various types of diagnostic tests. A large glossary of statistical terms indicates the appropriate applications of commonly used statistical techniques, providing definitions, presentation, and tips and guidelines for correct usage. Many new terms have been added to this glossary since the previous edition.

scholarly journals Index of Independence

2019 ◽  
Vol 2 (2) ◽  
pp. p1
Author(s):  
Ilija Barukčić
Keyword(s):  
Publication Bias ◽  
Study Design ◽  
Systematic Reviews ◽  
Meta Analysis ◽  
Scientific Research ◽  
Thought Experiments ◽  
Statistical Measures ◽  
Degree Of Certainty ◽  
Meta Analyses

Objective. Under certain circumstances, the results of multiple investigations – particularly, rigorously-designed trials, can be summarized by systematic reviews and meta-analyses. However, the results of properly conducted meta-analyses can but need not be stronger than single investigations, if (publication) bias is not considered to a necessary extent. Methods. In assessing the significance of publication bias due to study design simple to handle statistical measures for quantifying publication bias are developed and discussed which can be used as a characteristic of a meta-analysis. In addition, these measures may permit comparisons of publication biases between different meta-analyses. Results. Various properties and the performance of the new measures of publication bias are studied and illustrated using simulations and clearly described thought experiments. As a result, individual studies can be reviewed with a higher degree of certainty. Conclusions. Publication bias due to study design is a serious problem in scientific research, which can affect the validity and generalization of conclusions. The index of unfairness and the index of independence are of use to quantify publication bias and to improve the quality of systematic reviews and meta-analyses.

scholarly journals Anticoagulant-related nephropathy: systematic review and meta-analysis

2019 ◽  
Vol 12 (3) ◽  
pp. 400-407 ◽  
Author(s):  
Karolinny Borinelli de Aquino Moura ◽  
Paula Marques Prates Behrens ◽  
Rafaela Pirolli ◽  
Aimee Sauer ◽  
Dayana Melamed ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cohort Studies ◽  
Meta Analysis ◽  
Case Series ◽  
Case Control Studies ◽  
Cross Sectional ◽  
High Prevalence ◽  
Newcastle Ottawa Scale ◽  
Meta Analyses ◽  
Anticoagulated Patients

Abstract Background The aim of this study was to report the prevalence and mortality associated with anticoagulant-related nephropathy (ARN) through a systematic review of the literature. Methods Electronic searches were conducted in the Medline and EMBASE databases, and manual searches were performed in the reference lists of the identified studies. The studies were selected by two independent researchers, first by evaluating the titles and abstracts and then by reading the complete texts of the identified studies. Case series, cross-sectional studies, cohort studies and case–control studies reporting the prevalence and factors associated with ARN were selected. The methodological quality was assessed using the Newcastle–Ottawa scale. Meta-analyses of the prevalence of ARN and 5-year mortality using the random effects model were performed when possible. Heterogeneity was assessed using the I2 statistic. Results Five studies were included. Prevalence of ARN ranged from 19% to 63% among the four included cohort studies. Meta-analysis of these resulted in high heterogeneity [I2 96%, summary effect 31%; 95% confidence interval (CI) 22–42%]. Subgroup meta-analysis yielded an ARN prevalence of 20% among studies that included patients with fewer comorbidities (I2 12%; 95% CI 19–22%). In a direct comparison, meta-analysis of the 5-year mortality rate between anticoagulated patients who had experienced ARN and anticoagulated patients without ARN, patients with ARN were 91% more likely to die (risk ratio = 1.91; 95% CI 1.22–3; I2 87%). Risk factors for ARN that were reported in the literature included initial excessive anticoagulation, chronic kidney disease, age, diabetes, hypertension, cardiovascular disease and heart failure. Conclusions ARN studies are scarce and heterogeneous, and present significant methodological limitations. The high prevalence of ARN reported herein suggests that this entity is underdiagnosed in clinical practice. Mortality in patients with ARN seems to be high compared with patients without this condition in observational studies.

scholarly journals Differentiating PSP from MSA using MR planimetric measurements: a systematic review and meta-analysis

2021 ◽  
Author(s):  
Beatrice Heim ◽  
Florian Krismer ◽  
Klaus Seppi
Keyword(s):  
Sensitivity And Specificity ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Index Test ◽  
Study Quality ◽  
Parkinsonian Syndromes ◽  
Quantitative Mr ◽  
Meta Analyses ◽  
Planimetric Measurements

AbstractDifferential diagnosis of parkinsonian syndromes is considered one of the most challenging in neurology. Quantitative MR planimetric measurements were reported to discriminate between progressive supranuclear palsy (PSP) and non-PSP-parkinsonism. Several studies have used midbrain to pons ratio (M/P) and the Magnetic Resonance Parkinsonism Index (MRPI) in distinguishing PSP patients from those with Parkinson's disease. The current meta-analysis aimed to compare the performance of these measures in discriminating PSP from multiple system atrophy (MSA). A systematic MEDLINE review identified 59 out of 2984 studies allowing a calculation of sensitivity and specificity using the MRPI or M/P. Meta-analyses of results were carried out using random effects modelling. To assess study quality and risk of bias, the QUADAS-2 tool was used. Eight studies were suitable for analysis. The meta‐analysis showed a pooled sensitivity and specificity for the MRPI of PSP versus MSA of 79.2% (95% CI 72.7–84.4%) and 91.2% (95% CI 79.5–96.5%), and 84.1% (95% CI 77.2–89.2%) and 89.2% (95% CI 81.8–93.8%), respectively, for the M/P. The QUADAS-2 toolbox revealed a high risk of bias regarding the methodological quality of patient selection and index test, as all patients were seen in a specialized outpatient department without avoiding case control design and no predefined threshold was given regarding MRPI or M/P cut-offs. Planimetric brainstem measurements, in special the MRPI and M/P, yield high diagnostic accuracy for the discrimination of PSP from MSA. However, there is an urgent need for well-designed, prospective validation studies to ameliorate the concerns regarding the risk of bias.

scholarly journals Prognostic factors for chronic post-surgical pain after lung or pleural surgery: a protocol for a systematic review and meta-analysis

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e051554
Author(s):  
Pascal Richard David Clephas ◽  
Sanne Elisabeth Hoeks ◽  
Marialena Trivella ◽  
Christian S Guay ◽  
Preet Mohinder Singh ◽  
...  
Keyword(s):  
Systematic Review ◽  
Prognostic Factors ◽  
Prognostic Factor ◽  
Meta Analysis ◽  
Case Series ◽  
Related Factors ◽  
Surgical Pain ◽  
Literature Reviews ◽  
Chronic Post Surgical Pain

IntroductionChronic post-surgical pain (CPSP) after lung or pleural surgery is a common complication and associated with a decrease in quality of life, long-term use of pain medication and substantial economic costs. An abundant number of primary prognostic factor studies are published each year, but findings are often inconsistent, methods heterogeneous and the methodological quality questionable. Systematic reviews and meta-analyses are therefore needed to summarise the evidence.Methods and analysisThe reporting of this protocol adheres to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) checklist. We will include retrospective and prospective studies with a follow-up of at least 3 months reporting patient-related factors and surgery-related factors for any adult population. Randomised controlled trials will be included if they report on prognostic factors for CPSP after lung or pleural surgery. We will exclude case series, case reports, literature reviews, studies that do not report results for lung or pleural surgery separately and studies that modified the treatment or prognostic factor based on pain during the observation period. MEDLINE, Scopus, Web of Science, Embase, Cochrane, CINAHL, Google Scholar and relevant literature reviews will be searched. Independent pairs of two reviewers will assess studies in two stages based on the PICOTS criteria. We will use the Quality in Prognostic Studies tool for the quality assessment and the CHARMS-PF checklist for the data extraction of the included studies. The analyses will all be conducted separately for each identified prognostic factor. We will analyse adjusted and unadjusted estimated measures separately. When possible, evidence will be summarised with a meta-analysis and otherwise narratively. We will quantify heterogeneity by calculating the Q and I2 statistics. The heterogeneity will be further explored with meta-regression and subgroup analyses based on clinical knowledge. The quality of the evidence obtained will be evaluated according to the Grades of Recommendation Assessment, Development and Evaluation guideline 28.Ethics and disseminationEthical approval will not be necessary, as all data are already in the public domain. Results will be published in a peer-reviewed scientific journal.PROSPERO registration numberCRD42021227888.

scholarly journals Predictability of rotational tooth movement with orthodontic aligners comparing software-based and achieved data: A systematic review and meta-analysis of observational studies

2021 ◽  
pp. 146531252110272
Author(s):  
Despina Koletsi ◽  
Anna Iliadi ◽  
Theodore Eliades
Keyword(s):  
Effect Size ◽  
Tooth Movement ◽  
Data Extraction ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Patient Treatment ◽  
Qualitative Synthesis ◽  
Meta Analyses ◽  
Enamel Reduction

Objective: To evaluate all available evidence on the prediction of rotational tooth movements with aligners. Data sources: Seven databases of published and unpublished literature were searched up to 4 August 2020 for eligible studies. Data selection: Studies were deemed eligible if they included evaluation of rotational tooth movement with any type of aligner, through the comparison of software-based and actually achieved data after patient treatment. Data extraction and data synthesis: Data extraction was done independently and in duplicate and risk of bias assessment was performed with the use of the QUADAS-2 tool. Random effects meta-analyses with effect sizes and their 95% confidence intervals (CIs) were performed and the quality of the evidence was assessed through GRADE. Results: Seven articles were included in the qualitative synthesis, of which three contributed to meta-analyses. Overall results revealed a non-accurate prediction of the outcome for the software-based data, irrespective of the use of attachments or interproximal enamel reduction (IPR). Maxillary canines demonstrated the lowest percentage accuracy for rotational tooth movement (three studies: effect size = 47.9%; 95% CI = 27.2–69.5; P < 0.001), although high levels of heterogeneity were identified (I2: 86.9%; P < 0.001). Contrary, mandibular incisors presented the highest percentage accuracy for predicted rotational movement (two studies: effect size = 70.7%; 95% CI = 58.9–82.5; P < 0.001; I2: 0.0%; P = 0.48). Risk of bias was unclear to low overall, while quality of the evidence ranged from low to moderate. Conclusion: Allowing for all identified caveats, prediction of rotational tooth movements with aligner treatment does not appear accurate, especially for canines. Careful selection of patients and malocclusions for aligner treatment decisions remain challenging.

scholarly journals The association between Helicobacter pylori and obesity: a systematic review and meta-analysis of case–control studies

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ali Baradaran ◽  
Hojat Dehghanbanadaki ◽  
Sara Naderpour ◽  
Leila Mohammadi Pirkashani ◽  
Abdolhalim Rajabi ◽  
...  
Keyword(s):  
Odds Ratio ◽  
Meta Analysis ◽  
Pooled Analysis ◽  
Case Control ◽  
Case Control Studies ◽  
Newcastle Ottawa Scale ◽  
Prevalence Of Obesity ◽  
Quantitative Analyses ◽  
H Pylori

Abstract Introduction The relationship between H. pylori infection and obesity development has remained controversial among various studies. The aim of this study was to clarify the pooled effect of H. pylori infection on the development of obesity and vice versa. Methods We searched international databases including Medline (PubMed), Web of sciences, Scopus, EMBASE, Cochrane, Ovid, and CINHAL to retrieve all case–control studies reporting the effect of H. pylori on obesity and vice versa, which had been published in English between January 1990 and June 2019. The quality of included studies was assessed by the Modified Newcastle–Ottawa Scale for Case–Control studies. The logarithm of the odds ratio (OR) and its standard error was used for the meta-analysis. Results Eight case–control studies with 25,519 participants were included for qualitative and quantitative analyses. The pooled analysis showed that obese participants had a higher risk of H. pylori infection than lean participants with an odds ratio of 1.46 (95%CI: 1.26, 1.68). Also, the pooled analysis revealed that participants infected by H. pylori had a higher risk of obesity than non-infected participants with an odds ratio of 1.01 (95%CI: 1.01, 1.02). Conclusion The results of this meta-analysis showed that there was a positive correlation between the risk of H. pylori infection and the prevalence of obesity development. Thus, H. pylori positive patients were more likely to be obese, and obese individuals had higher risks of H. pylori infection.

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