scholarly journals Commentary on Di Castelnuovo et al .: The internal and external validity of cohort studies that measure J‐shaped curves for all‐cause mortality

Addiction ◽  
2021 ◽  
Author(s):  
Kevin D. Shield ◽  
Jürgen Rehm
Keyword(s):  
Cohort Studies ◽  
External Validity ◽  
All Cause Mortality ◽  
Internal And External Validity

The German Post-Critical Belief Scale: Internal and External Validity

2003 ◽  
Vol 34 (4) ◽  
pp. 219-226 ◽  
Author(s):  
Bart Duriez ◽  
Claudia Appel ◽  
Dirk Hutsebaut
Keyword(s):  
Internal Structure ◽  
Present Article ◽  
External Validity ◽  
German Version ◽  
Dutch Version ◽  
German Sample ◽  
Belief Scale ◽  
Internal And External Validity

Abstract: Recently, Duriez, Fontaine and Hutsebaut (2000) and Fontaine, Duriez, Luyten and Hutsebaut (2003) constructed the Post-Critical Belief Scale in order to measure the two religiosity dimensions along which Wulff (1991 , 1997 ) summarized the various possible approaches to religion: Exclusion vs. Inclusion of Transcendence and Literal vs. Symbolic. In the present article, the German version of this scale is presented. Results obtained in a heterogeneous German sample (N = 216) suggest that the internal structure of the German version fits the internal structure of the original Dutch version. Moreover, the observed relation between the Literal vs. Symbolic dimension and racism, which was in line with previous studies ( Duriez, in press ), supports the external validity of the German version.

scholarly journals Dose–Response Relation between Tea Consumption and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Population-Based Studies

2020 ◽  
Vol 11 (4) ◽  
pp. 790-814 ◽  
Author(s):  
Mei Chung ◽  
Naisi Zhao ◽  
Deena Wang ◽  
Marissa Shams-White ◽  
Micaela Karlsen ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Cohort Studies ◽  
Prospective Cohort ◽  
Lower Risk ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Tea Consumption ◽  
All Cause Mortality ◽  
Specific Mortality ◽  
Cvd Mortality

ABSTRACT Tea flavonoids have been suggested to offer potential benefits to cardiovascular health. This review synthesized the evidence on the relation between tea consumption and risks of cardiovascular disease (CVD) and all-cause mortality among generally healthy adults. PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, Food Science and Technology Abstracts, and Ovid CAB Abstract databases were searched to identify English-language publications through 1 November 2019, including randomized trials, prospective cohort studies, and nested case-control (or case-cohort) studies with data on tea consumption and risk of incident cardiovascular events (cardiac or peripheral vascular events), stroke events (including mortality), CVD-specific mortality, or all-cause mortality. Data from 39 prospective cohort publications were synthesized. Linear meta-regression showed that each cup (236.6 mL)  increase in daily tea consumption (estimated 280 mg  and 338 mg  total flavonoids/d for black and green tea, respectively) was associated with an average 4% lower risk of CVD mortality, a 2% lower risk of CVD events, a 4% lower risk of stroke, and a 1.5% lower risk of all-cause mortality. Subgroup meta-analysis results showed that the magnitude of association was larger in elderly individuals for both CVD mortality (n = 4; pooled adjusted RR: 0.89; 95% CI: 0.83, 0.96; P = 0.001), with large heterogeneity (I2 = 72.4%), and all-cause mortality (n = 3; pooled adjusted RR: 0.92; 95% CI: 0.90, 0.94; P < 0.0001; I2 = 0.3%). Generally, studies with higher risk of bias appeared to show larger magnitudes of associations than studies with lower risk of bias. Strength of evidence was rated as low and moderate (depending on study population age group) for CVD-specific mortality outcome and was rated as low for CVD events, stroke, and all-cause mortality outcomes. Daily tea intake as part of a healthy habitual dietary pattern may be associated with lower risks of CVD and all-cause mortality among adults.

scholarly journals Lipid profile and prognosis in patients with coronary heart disease: a meta-analysis of prospective cohort studies

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangmei Zhao ◽  
Dongying Wang ◽  
Lijie Qin
Keyword(s):  
Coronary Heart Disease ◽  
Heart Disease ◽  
Cohort Studies ◽  
Lipid Profile ◽  
Prospective Cohort ◽  
Cardiac Death ◽  
Meta Analysis ◽  
Prospective Cohort Studies ◽  
All Cause Mortality ◽  
Reduced Risk

Abstract Background This meta-analysis based on prospective cohort studies aimed to evaluate the associations of lipid profiles with the risk of major adverse cardiovascular outcomes in patients with coronary heart disease (CHD). Methods The PubMed, Embase, and Cochrane Library electronic databases were systematically searched for prospective cohort study published through December 2019, and the pooled results were calculated using the random-effects model. Results Twenty-one studies with a total of 76,221 patients with CHD met the inclusion criteria. The per standard deviation (SD) increase in triglyceride was associated with a reduced risk of major adverse cardiovascular events (MACE). Furthermore, the per SD increase in high-density lipoprotein cholesterol (HDL-C) was associated with a reduced risk of cardiac death, whereas patients with lower HDL-C were associated with an increased risk of MACE, all-cause mortality, and cardiac death. Finally, the risk of MACE was significantly increased in patients with CHD with high lipoprotein(a) levels. Conclusions The results of this study suggested that lipid profile variables could predict major cardiovascular outcomes and all-cause mortality in patients with CHD.

scholarly journals A novel preference-informed complementary trial (PICT) design for clinical trial research influenced by strong patient preferences

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Samina Ali ◽  
◽  
Gareth Hopkin ◽  
Naveen Poonai ◽  
Lawrence Richer ◽  
...  
Keyword(s):  
External Validity ◽  
Treatment Options ◽  
Internal Validity ◽  
Clinical Effectiveness ◽  
Drop Out ◽  
Innovative Design ◽  
Clinical Trial Research ◽  
Research Questions ◽  
Internal And External Validity ◽  
Treatment Population

Abstract Background Patients and their families often have preferences for medical care that relate to wider considerations beyond the clinical effectiveness of the proposed interventions. Traditionally, these preferences have not been adequately considered in research. Research questions where patients and families have strong preferences may not be appropriate for traditional randomized controlled trials (RCTs) due to threats to internal and external validity, as there may be high levels of drop-out and non-adherence or recruitment of a sample that is not representative of the treatment population. Several preference-informed designs have been developed to address problems with traditional RCTs, but these designs have their own limitations and may not be suitable for many research questions where strong preferences and opinions are present. Methods In this paper, we propose a novel and innovative preference-informed complementary trial (PICT) design which addresses key weaknesses with both traditional RCTs and available preference-informed designs. In the PICT design, complementary trials would be operated within a single study, and patients and/or families would be given the opportunity to choose between a trial with all treatment options available and a trial with treatment options that exclude the option which is subject to strong preferences. This approach would allow those with strong preferences to take part in research and would improve external validity through recruiting more representative populations and internal validity. Here we discuss the strengths and limitations of the PICT design and considerations for analysis and present a motivating example for the design based on the use of opioids for pain management for children with musculoskeletal injuries. Conclusions PICTs provide a novel and innovative design for clinical trials with more than two arms, which can address problems with existing preference-informed trial designs and enhance the ability of researchers to reflect shared decision-making in research as well as improving the validity of trials of topics with strong preferences.

scholarly journals Multi-trajectories of lipid indices with incident cardiovascular disease, heart failure, and all-cause mortality: 23 years follow-up of two US cohort studies

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Fatemeh Koohi ◽  
Davood Khalili ◽  
Mohammad Ali Mansournia ◽  
Farzad Hadaegh ◽  
Hamid Soori
Keyword(s):  
Heart Failure ◽  
Cardiovascular Disease ◽  
Cohort Studies ◽  
Significant Risk ◽  
Density Lipoprotein ◽  
Lipid Levels ◽  
Cvd Risk ◽  
All Cause Mortality ◽  
Over Time

Abstract Background Understanding the distinct patterns (trajectories) of variation in blood lipid levels before diagnosing cardiovascular disease (CVD) might carry important implications for improving disease prevention or treatment. Methods We investigated 14,373 participants (45.5% men) aged 45–84 from two large US prospective cohort studies with a median of 23 years follow-up. First, we jointly estimated developmental trajectories of lipid indices, including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) concentrations using group-based multi-trajectory modeling. Then, the association of identified multi-trajectories with incident CVD, heart failure, and all-cause mortality were examined using Cox proportional hazard model. Results Seven distinct multi-trajectories were identified. The majority of participants (approximately 80%) exhibited decreasing LDL-C but rising TG levels and relatively stable HDL-C levels. Compared to the individuals with healthy and stable LDL-C, HDL-C, and TG levels, those in other groups were at significant risk of incident CVD after adjusting for other conventional risk factors. Individuals with the highest but decreasing LDL-C and borderline high and rising TG levels over time were at the highest risk than those in other groups with a 2.22-fold risk of CVD. Also, those with the highest and increased triglyceride levels over time, over optimal and decreasing LDL-C levels, and the lowest HDL-C profile had a nearly 1.84 times CVD risk. Even individuals in the multi-trajectory group with the highest HDL-C, optimal LDL-C, and optimal TG levels had a significant risk (HR, 1.45; 95% CI 1.02–2.08). Furthermore, only those with the highest HDL-C profile increased the risk of heart failure by 1.5-fold (95% CI 1.07–2.06). Conclusions The trajectories and risk of CVD identified in this study demonstrated that despite a decline in LDL-C over time, a significant amount of residual risk for CVD remains. These findings suggest the impact of the increasing trend of TG on CVD risk and emphasize the importance of assessing the lipid levels at each visit and undertaking potential interventions that lower triglyceride concentrations to reduce the residual risk of CVD, even among those with the optimal LDL-C level.

scholarly journals Efficacy and Safety of Oral Anticoagulants in Patients with Systolic Heart Failure in Sinus Rhythm: A Systematic Review and Meta-analysis of Randomized Controlled Trials and Cohort Studies

TH Open ◽  
2020 ◽  
Vol 04 (04) ◽  
pp. e383-e392
Author(s):  
Marie H. Nygaard ◽  
Anne-Mette Hvas ◽  
Erik L. Grove
Keyword(s):  
Heart Failure ◽  
Sinus Rhythm ◽  
Cohort Studies ◽  
Antiplatelet Therapy ◽  
Meta Analysis ◽  
Oral Anticoagulants ◽  
Controlled Trials ◽  
Efficacy And Safety ◽  
Randomized Controlled ◽  
All Cause Mortality

Abstract Introduction There is conflicting evidence on the risk–benefit ratio of oral anticoagulants (OAC) in heart failure (HF) patients without atrial fibrillation. We aimed to evaluate the efficacy and safety of OAC in HF patients in sinus rhythm. Methods A systematic literature search was conducted using PubMed and Embase. We included randomized controlled trials (RCT) and cohort studies, comparing OAC with antiplatelet or no treatment/placebo in patients with HF. Outcomes evaluated were stroke, myocardial infarction (MI), all-cause mortality, and major bleeding. Results Five RCTs and three cohort studies were included. OAC was associated with a reduced risk of ischemic stroke when compared with no treatment/placebo (odds ratio [OR] = 0.67, 95% confidence interval [CI]: [0.47, 0.94]) and antiplatelet therapy (OR = 0.55, 95% CI: [0.37, 0.81]). No significant reduction was found in MI, when OAC was compared with no treatment/placebo (OR = 0.82, 95% CI: [0.63, 1.07]) or antiplatelet therapy (OR = 1.04, 95% CI: [0.60, 1.81]). The all-cause mortality analysis showed no significant reduction when comparing OAC with no treatment/placebo (OR = 0.99, 95% CI: [0.87, 1.12]) or antiplatelet therapy (OR = 1.00, 95% CI: [0.86, 1.16]). The nonsignificant effect of OAC on all-cause mortality was supported by a meta-analysis of the three cohort studies (OR = 1.02, 95% CI: [0.75, 1.38]). Patients treated with OAC had a significantly higher risk of major bleeding than patients receiving antiplatelet therapy (OR = 2.16, 95% CI: [1.55, 3.00]) and a numerically higher risk when compared with no treatment/placebo (OR = 2.38, 95% CI: [0.87, 6.49]). Conclusion The present study does not support the routine use of OAC in patients with HF in sinus rhythm.

Internal and External Validity Issues

2013 ◽  
pp. 1094-1094
Author(s):  
Marie Boltz ◽  
Holly Rau ◽  
Paula Williams ◽  
Holly Rau ◽  
Paula Williams ◽  
...  
Keyword(s):  
External Validity ◽  
Internal And External Validity

scholarly journals High Fidelity Microsurgical Simulation: The Thiel Model and Evaluation Instrument

2018 ◽  
Vol 27 (2) ◽  
pp. 118-124 ◽  
Author(s):  
Andrei Odobescu ◽  
Isak Goodwin ◽  
Djamal Berbiche ◽  
Joseph BouMerhi ◽  
Patrick G. Harris ◽  
...  
Keyword(s):  
External Validity ◽  
Internal Validity ◽  
High Fidelity ◽  
Evaluation Instrument ◽  
Intra Class Correlation ◽  
Validity Measures ◽  
The Difference ◽  
Fidelity Model ◽  
Junior Residents ◽  
Internal And External Validity

Background: The Thiel embalmment method has recently been used in a number of medical simulation fields. The authors investigate the use of Thiel vessels as a high fidelity model for microvascular simulation and propose a new checklist-based evaluation instrument for microsurgical training. Methods: Thirteen residents and 2 attending microsurgeons performed video recorded microvascular anastomoses on Thiel embalmed arteries that were evaluated using a new evaluation instrument (Microvascular Evaluation Scale) by 4 fellowship trained microsurgeons. The internal validity was assessed using the Cronbach coefficient. The external validity was verified using regression models. Results: The reliability assessment revealed an excellent intra-class correlation of 0.89. When comparing scores obtained by participants from different levels of training, attending surgeons and senior residents (Post Graduate Year [PGY] 4-5) scored significantly better than junior residents (PGY 1-3). The difference between senior residents and attending surgeons was not significant. When considering microsurgical experience, the differences were significant between the advanced group and the minimal and moderate experience groups. The differences between minimal and moderate experience groups were not significant. Based on the data obtained, a score of 8 would translate into a level of microsurgical competence appropriate for clinical microsurgery. Conclusions: Thiel cadaveric vessels are a high fidelity model for microsurgical simulation. Excellent internal and external validity measures were obtained using the Microvascular Evaluation Scale (MVES).

scholarly journals Editorial 29(6)

2013 ◽  
Vol 29 (6) ◽  
Author(s):  
Barney Dalgarno ◽  
Sue Bennett ◽  
Gregor Kennedy
Keyword(s):  
Educational Technology ◽  
Research Design ◽  
Experimental Research ◽  
External Validity ◽  
Learning Design ◽  
Learning Effects ◽  
Research In Education ◽  
The Right ◽  
Internal And External Validity

<p>We are pleased to present a new issue of AJET and in the editorial we would like to discuss some of the challenges involved in undertaking and reporting on experimental research in education and in educational technology specifically. The first challenge relates to the need to find the right balance between internal and external validity in the research design, while the second relates to the need for clarity about the likely causes of learning effects: technology or learning design.</p>

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