Analysis of repeated measurements in clinical studies: departures from study design

2003 ◽  
Author(s):  
S. Wagenpfeil ◽  
M. Hennig ◽  
R. Kates ◽  
A. Neiss
Keyword(s):  
Study Design ◽  
Clinical Studies ◽  
Repeated Measurements

scholarly journals Time arrow in published clinical studies/trials indexed in MEDLINE: a systematic analysis of Retrospective vs Prospective study design, from 1960 to 2017.

2018 ◽  
Author(s):  
Michele M Ciulla ◽  
Patrizia Vivona
Keyword(s):  
Prospective Study ◽  
Study Design ◽  
Low Income ◽  
Clinical Studies ◽  
Human Subjects ◽  
Systematic Analysis ◽  
Time Line ◽  
Time Arrow ◽  
Prospective Study Design ◽  
Single Time Point

Clinical studies/trials are experiments or observations on human subjects considered by the scientific community the most appropriate instrument to answer specific research questions on interventions on health outcomes. The time-line of the observations might be focused on a single time point or to follow time, backward or forward, in the so called, respectively, retrospective and prospective study design. Since the retrospective approach has been criticized for the possible sources of errors due to bias and confounding, we aimed this study to assess if there is a prevalence of retrospective vs prospective design in the clinical studies/trials by querying MEDLINE. Our results on a sample of 1,438,872 studies/trials, (yrs 1960-2017), support a prevalence of retrospective, respectively 55% vs 45%. To explain this result, arandom sub-sample of studies where the country of origin was reported (n=1576) was categorized in high and low-income based onthe nominal Gross Domestic Product (GDP) and matched with the topic of the research. As expected, the absolute majority of studies/trials are carried on by high-income countries, respectively 86% vs 14%; even if a slight prevalence of retrospective was recorded in both income groups, nonetheless the most part of prospective studies are carried out by high-GDP countries, 85% vs 15%. Finally the differences in the design of the study are understandable when considering the topic of the research.

scholarly journals Reporting Standards for Clinical and Translational Research

2019 ◽  
pp. 69-73
Author(s):  
Fengyu Zhang ◽  
Claude Hughes
Keyword(s):  
Clinical Research ◽  
Study Design ◽  
Repeated Measurements ◽  
Sufficient Information ◽  
Reporting Standards ◽  
Preclinical Research ◽  
Study Protocols ◽  
Real World Evidence ◽  
Funding Agencies ◽  
Rigorous Study

Transparency in reporting the results of clinical and preclinical research is critical for unbiased publications. Funding agencies, publishers, and regulators have the responsibility to advocate and implement reporting standards for rigorous design. While individual study protocols may have included these standards, the items reported in the respective publications have often been inconsistent or lack transparency. This editorial intends to provide some specific guidelines for reporting results of clinical research with standards required for rigorous study design. We recommend that reporting clinical research should include sufficient information on study design and analysis plan that contains data processing, quality assurance, and appropriate methods used for rigorous statistical analysis or modeling. Any discrepancy between publications and original study design should be disclosed and discussed. Additionally, recent advances in the analysis of outcome with repeated measurements and statistical modeling should be employed to obtain unbiased estimates. Finally, we briefly discuss some issues reporting real-world evidence in clinical research.

scholarly journals STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. Translation to Russian

2021 ◽  
Author(s):  
Jérémie F. Cohen ◽  
Daniël A. Korevaar ◽  
Douglas G. Altman ◽  
David E. Bruns ◽  
Constantine A. Gatsonis ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Study Design ◽  
Clinical Studies ◽  
Russian Translation ◽  
Risk Of Bias ◽  
Reporting Guidelines ◽  
Diagnostic Accuracy Study ◽  
Sufficient Detail ◽  
Accuracy Study ◽  
Patient Groups

Diagnostic accuracy studies are, like other clinical studies, at risk of bias due to shortcomings in design and conduct, and the results of a diagnostic accuracy study may not apply to other patient groups and settings. Readers of study reports need to be informed about study design and conduct, in sufficient detail to judge the trustworthiness and applicability of the study findings. The STARD statement (Standards for Reporting of Diagnostic Accuracy Studies) was developed to improve the completeness and transparency of reports of diagnostic accuracy studies. STARD contains a list of essential items that can be used as a checklist, by authors, reviewers and other readers, to ensure that a report of a diagnostic accuracy study contains the necessary information. STARD was recently updated. All updated STARD materials, including the checklist, are available at http://www.equator-network.org/reporting-guidelines/stard. Here, we present the STARD 2015 explanation and elaboration document. Through commented examples of appropriate reporting, we clarify the rationale for each of the 30 items on the STARD 2015 checklist, and describe what is expected from authors in developing sufficiently informative study reports. This article is the reprint with Russian translation of the original that can be observed here: Cohen JF, Korevaar DA, Altman DG, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. BMJ Open 2016;6:e012799. doi: 10.1136/bmjopen-2016-012799

scholarly journals Time arrow in published clinical studies/trials indexed in MEDLINE: a systematic analysis of retrospective vs. prospective study design, from 1960 to 2017

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6363
Author(s):  
Michele M. Ciulla ◽  
Patrizia Vivona
Keyword(s):  
Prospective Study ◽  
Study Design ◽  
Low Income ◽  
Clinical Studies ◽  
Human Subjects ◽  
Systematic Analysis ◽  
Time Line ◽  
Time Arrow ◽  
Prospective Study Design ◽  
Single Time Point

Clinical studies/trials are experiments or observations on human subjects considered by the scientific community the most appropriate instrument to answer specific research questions on interventions on health outcomes. The time-line of the observations might be focused on a single time point or to follow time, backward or forward, in the so called, respectively, retrospective and prospective study design. Since the retrospective approach has been criticized for the possible sources of errors due to bias and confounding, we aimed this study to assess if there is a prevalence of retrospective vs. prospective design in the clinical studies/trials by querying MEDLINE. Our results on a sample of 1,438,872 studies/trials, (yrs 1960–2017), support a prevalence of retrospective, respectively 55% vs. 45%. To explain this result, a random sub-sample of studies where the country of origin was reported (n = 1,576) was categorized in high and low-income based onthe nominal Gross Domestic Product (GDP) and matched with the topic of the research. As expected, the absolute majority of studies/trials are carried on by high-income countries, respectively 86% vs. 14%; even if a slight prevalence of retrospective was recorded in both income groups, for the most part prospective studies are carried out by high-GDP countries, 85% vs. 15%. Finally, the differences in the design of the study are understandable when considering the topic of the research.

Shortcomings in Design and Analysis of Clinical Studies on Bleeding and Thrombosis in Patients with Cirrhosis

2020 ◽  
Vol 46 (06) ◽  
pp. 665-672 ◽  
Author(s):  
Patrick Northup ◽  
Jessica Davis
Keyword(s):  
Best Practices ◽  
Study Design ◽  
Clinical Studies ◽  
Clinical Care ◽  
Decompensated Cirrhosis ◽  
Careful Study ◽  
Serious Adverse Events ◽  
Scientific Success ◽  
Standard Practices ◽  
Made In

AbstractSignificant gains have been made in our understanding of bleeding and thrombosis in patients with liver disease in recent years, with concurrent exponential growth in the scientific literature published in this realm. Clinical studies of this population are challenging for multiple reasons including some hurdles unique to this population. Cirrhosis patients as a whole, especially those with decompensated cirrhosis, are a high-risk and heterogeneous population prone to serious adverse events. Outcomes of bleeding and thrombosis are relatively rare and lack standardized, validated definitions. Standard practices for clinical care have evolved rapidly and rendered some control data uninformative. We aim to highlight these challenges and make recommendations for best practices for future study design and implementation. Multidisciplinary collaboration with proceduralists, careful study design including attention to validated clinically relevant outcomes, and aggressive pursuit of all funding streams will be key to continued scientific success in this burgeoning field.

Citation Analysis of Articles about Hand Surgery Published in Orthopaedic and Hand Surgery Journals

2019 ◽  
Vol 24 (01) ◽  
pp. 36-44 ◽  
Author(s):  
Yuki Fujihara ◽  
Nasa Fujihara ◽  
Michiro Yamamoto ◽  
Hitoshi Hirata
Keyword(s):  
Clinical Trial ◽  
Sample Size ◽  
Randomized Clinical Trial ◽  
Study Design ◽  
Comparative Studies ◽  
Clinical Studies ◽  
Hand Surgery ◽  
The Impact ◽  
Larger Sample ◽  
Surgery Journals

Background: To date, little is known about the characteristics of highly cited studies in hand surgery compared with other orthopaedic subspecialties. We aimed to assess the position of hand surgery within the orthopedic surgery literature. Methods: We conducted a bibliographic analysis using the Web of Science database to review 1,568 articles published between January 2012 and December 2012 in 4 relevant general orthopedic and 2 hand surgery journals. We used the number of citations within 3 years of publication to measure the impact of each paper. To analyze prognostic factors using logistic regression analysis, we extracted data on orthopedic subspecialty, published journal, location of authorship, and type of study for all articles. For clinical studies, we also recorded details on study design and sample size. Results: Of eligible hand surgery articles (n = 307), the majority (62%) were case reports/series. Only 19% were comparative studies, comprising a significantly smaller proportion of comparative studies from other subspecialties in general orthopedic journals. Systematic reviews/meta-analyses generated a significantly higher number of average citations, whereas educational reviews were consistently cited less frequently than other study types (14.9 and 6.1 average citations, respectively). Being published in the Journal of Bone and Joint Surgery, American volume, having authorship in North America or Europe and Australia, focusing on subspecialties like hip & knee, sports, or shoulder, utilizing a comparative or randomized clinical trial study design, and having a larger sample size increased the odds of receiving more citations. Conclusions: Clinical studies related to hand surgery published in general orthopedic journals are most often of lower quality study design. Having a larger sample size or using a comparative study or randomized clinical trial design can improve the quality of study and may ultimately increase the impact factor of hand surgery journals.

Evaluation of Stem Cell-Derived Cellular Therapy Products

2020 ◽  
pp. 019262331989789
Author(s):  
Alys E. Bradley ◽  
Lauren Black
Keyword(s):  
Stem Cell ◽  
Study Design ◽  
Clinical Studies ◽  
Cellular Therapy ◽  
Scientific Integrity ◽  
Preclinical Studies ◽  
Cell Markers ◽  
Contract Research ◽  
Research Organizations ◽  
Case Basis

Although there is an increase in the development of new cellular therapies, few guidelines have been published to assist in the design of preclinical studies. As no product and therapeutic intention is entirely alike regulators and Contract Research Organizations need to treat each project on a case-by-case basis. One of the most important considerations in study design is to retain all tissues from the study, thereby allowing for further analysis of tissues should unexpected effects be seen in clinical studies. Input from the pathologist at the earliest stages of study design regarding animal selection, cell markers, and phased tissue examination improves the scientific integrity of the study.

Triptan nonresponders: Do they exist and who are they?

Cephalalgia ◽  
2013 ◽  
Vol 33 (11) ◽  
pp. 891-896 ◽  
Author(s):  
Michele Viana ◽  
Armando A Genazzani ◽  
Salvatore Terrazzino ◽  
Giuseppe Nappi ◽  
Peter J Goadsby
Keyword(s):  
Effective Treatment ◽  
Treatment Option ◽  
Study Design ◽  
Clinical Studies ◽  
Scientific Data ◽  
Controlled Trials ◽  
Pragmatic Study

Background: Triptans represent the best treatment option for most migraine attacks, although this is not as well studied as it might be in controlled trials. Their efficacy and tolerability vary, both between agents, and from patient to patient, with about 30%–40% of patients not responding adequately to therapy. As yet unexplained, the failure of one triptan does not predict failure with another, and therefore triptan nonresponders cannot be defined as individuals who have failed a single triptan. Five clinical studies provide evidence that switching from a triptan that is ineffective to a second one can result in effective treatment in a proportion of patients. Systematic studies investigating whether there are patients who do not respond to all triptans in all formulations are lacking. Methods: Here we discuss the importance of identifying triptan nonresponders, the literature supporting their existence, and the issues to be resolved to design trials to investigate this. Conclusion: So far, no scientific data about the presence of a triptan nonresponder population are available. We propose a pragmatic study design to assess the existence of this subpopulation, recognizing the complexity of the question and the likelihood that more than one issue is at play in nonresponders.

scholarly journals Criteria for evaluating studies at scientific medical events

Mastology ◽  
2020 ◽  
Vol 30 ◽  
Author(s):  
René Aloisio da Costa Vieira ◽  
Tatiana Carvalho de Souza Bonetti ◽  
Marcia Maria Chiquitelli Marques ◽  
Gil Facina
Keyword(s):  
Study Design ◽  
Clinical Studies ◽  
Case Reports ◽  
Scientific Evidence ◽  
Place Value ◽  
Improve Quality ◽  
Medical Journals ◽  
The Face ◽  
Translational Studies

Medical journals value the quality of studies. Scientific events are spaces for discussion in the face of scientific advances, innovation and consensus. In them, space is opened for the presentation of clinical studies, translational studies, experience reports and videos, with the best-designed studies being selected and awarded. The lack of clear criteria allows for differences in assessments, making it difficult to place value on situations associated with research. In order to improve quality, it is necessary to evaluate ethics, the hierarchy of scientific evidence (methodology), the study design, the originality, the relevance, and the linearity of the material presented. The present study aims to discuss these points, presenting proposals to be used in the evaluation of clinical studies, translational studies, case reports and videos in scientific medical events.

Sign in / Sign up

Export Citation Format

Share Document