Using Evidence Factors to Clarify Exposure Biomarkers

2020 ◽  
Vol 189 (3) ◽  
pp. 243-249
Author(s):  
Bikram Karmakar ◽  
Dylan S Small ◽  
Paul R Rosenbaum
Keyword(s):  
Cigarette Smoking ◽  
Observational Study ◽  
Treatment Effect ◽  
Meta Analysis ◽  
The Other ◽  
Central Aspect ◽  
Exposure Biomarker ◽  
Exposure Biomarkers ◽  
External Measure

Abstract A study has 2 evidence factors if it permits 2 statistically independent inferences about 1 treatment effect such that each factor is immune to some bias that would invalidate the other factor. Because the 2 factors are statistically independent, the evidence they provide can be combined using methods associated with meta-analysis for independent studies, despite using the same data twice in different ways. We illustrate evidence factors, applying them in a new way in investigations that have both an exposure biomarker and a coarse external measure of exposure to a treatment. To illustrate, we consider the possible effects of cigarette smoking on homocysteine levels, with self-reported smoking and a cotinine biomarker. We examine joint sensitivity of 2 factors to bias from confounding, a central aspect of any observational study.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

2018 ◽  
Author(s):  
Amir Forouharfar
Keyword(s):  
Social Entrepreneurship ◽  
Social Constructivism ◽  
Social Epistemology ◽  
American English ◽  
Meta Analysis ◽  
Research Question ◽  
Knowledge Structure ◽  
Scientific Field ◽  
The Other ◽  
First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1)<b> </b>is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE.<b> </b>Based on the sections,<b> </b>the study relied on the relevant philosophical schools of thought in <i>Epistemology </i>(e.g. <i>Empiricism</i>, <i>Rationalism</i>, <i>Skepticism</i>, <i>Internalism</i> vs. <i>Externalism</i>,<i> Essentialism, Social Constructivism</i>, <i>Social Epistemology, etc.</i>) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion,<i> Corpus of Contemporary American English (COCA)</i> for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

Impulsivity and Aggression: A Meta-analysis Using the UPPS Model of Impulsivity

2019 ◽  
Author(s):  
Konrad Bresin
Keyword(s):  
Structural Equation Modeling ◽  
Sensation Seeking ◽  
Structural Equation ◽  
Meta Analysis ◽  
The Other ◽  
Equation Modeling ◽  
Negative Urgency ◽  
Two Stage ◽  
Trait Impulsivity

Trait impulsivity has long been proposed to play a role in aggression, but the results across studies have been mixed. One possible explanation for the mixed results is that impulsivity is a multifaceted construct and some, but not all, facets are related to aggression. The goal of the current meta-analysis was to determine the relation between the different facets of impulsivity (i.e., negative urgency, positive urgency, lack of premeditation, lack of perseverance, and sensation seeking) and aggression. The results from 93 papers with 105 unique samples (N = 36, 215) showed significant and small-to-medium correlations between each facet of impulsivity and aggression across several different forms of aggression, with more impulsivity being associated with more aggression. Moreover, negative urgency (r = .24, 95% [.18, .29]), positive urgency (r = .34, 95% [.19, .44]), and lack of premeditation (r = .23, 95% [.20, .26]) had significantly stronger associations with aggression than the other scales (rs &lt; .18). Two-stage meta-analytic structural equation modeling showed that these effects were not due to overlap among facets of impulsivity. These results help advance the field of aggression research by clarifying the role of impulsivity and may be of interest to researchers and practitioners in several disciplines.

scholarly journals Outcomes associated with modern treatment paradigms in connective tissue disease (CTD)-associated pulmonary arterial hypertension (PAH): a meta-analysis of randomized controlled trials (RCTs)

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
V McLaughlin ◽  
C Zhao ◽  
J.G Coghlan ◽  
L.S Chung ◽  
S.C Mathai ◽  
...  
Keyword(s):  
Drug Treatment ◽  
Treatment Effect ◽  
Meta Analysis ◽  
Response To Treatment ◽  
Funding Source ◽  
Class Iii ◽  
Inclusion Criteria ◽  
Private Company ◽  
Mortality Event

Abstract Background CTD-PAH has historically represented a PAH subtype with poor prognosis. New therapies, as well as combination therapy approaches targeting multiple pathways have been approved for PAH based on RCTs. CTD-PAH patients comprise a subgroup of the RCT populations and efficacy analyses are based on subgroup analyses which can be less reliable than the overall analysis. We conducted a meta-analysis of RCTs of approved PAH therapies to evaluate outcomes of patients with CTD-PAH. Purpose To use meta-analysis to determine response to treatment in patients with CTD-PAH. Methods The PubMed and EMBASE databases were searched for English-only articles published between January 1, 2000 and November 25, 2019. Inclusion criteria were multicenter RCTs that enrolled adults with WHO group 1 pulmonary hypertension (PAH); enrollment in 2000 or later; long-term clinical morbidity and/or mortality event or 6-minute walk distance (6MWD) as an efficacy endpoint reported for ≥30 patients with CTD-PAH; and evaluation of a US Food and Drug Administration-approved PAH therapy. The primary outcomes were treatment effect as measured by the study time to first morbidity or morality event and change in 6MWD from baseline to between 3–6 months, per the data provided in each article. Results from individual studies were combined using a random-effects model for overall study population (PAH patients) and the subgroup of CTD-PAH patients. Results Ten RCTs (N=4329 PAH patients; n=1263 (29%) with CTD-PAH) met inclusion criteria and were included in the meta-analysis. At baseline, PAH patients had a mean age of 50 years, approximately 78% were female, and approximately 58% had functional class III or IV disease. These characteristics were balanced between treatment and control groups. Baseline 6MWD was 356 m for the overall population and 337 m for patients with CTD-PAH. Five RCTs (N=3172; n=941 with CTD-PAH [30%]) reported hazard ratios (HRs) for time to a morbidity or mortality event by drug treatment and PAH etiology: overall population HR=0.63 (95% confidence interval [CI], 0.56–0.72; P&lt;0.001); CTD-PAH population HR=0.64 (95% CI, 0.51–0.80; P&lt;0.001) (Figure). Nine RCTs reported mean change with drug treatment from baseline to 3 to 6 months in 6MWD for PAH and CTD patients: 33.9 m (95% CI, 21.9–45.9; P&lt;0.001) in the overall population; 20.2 m (95% CI, 10.8–29.7; P&lt;0.001) in CTD-PAH patients. Conclusions The improvement in 6MWD in patients with CTD-PAH is smaller than in those with other types of PAH, perhaps reflecting comorbidities and CTD-induced mobility constraints, independent of their cardiopulmonary capacity. Data from long term clinical morbidity/mortality endpoint studies in this large group of patients with CTD-PAH demonstrate that these patients derive significant benefit from currently available PAH therapies which, in many patients, comprised the addition of a drug targeting a second or third pathway involved in the pathophysiology of PAH. Treatment effect on morbidity/mortality Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Actelion Pharmaceuticals US, Inc.

scholarly journals ACCURACY OF CARDIOVASCULAR TRIAL OUTCOME ASCERTAINMENT AND TREATMENT EFFECT ESTIMATES FROM ROUTINE HEALTH DATA: A SYSTEMATIC REVIEW AND META-ANALYSIS

2021 ◽  
Vol 77 (18) ◽  
pp. 187
Author(s):  
Craig Rodrigues ◽  
Ayodele Odutayo ◽  
Sagar Patel ◽  
Arnav Argarwal ◽  
Bruno Roza da Costa ◽  
...  
Keyword(s):  
Systematic Review ◽  
Treatment Effect ◽  
Meta Analysis ◽  
Health Data ◽  
Trial Outcome

scholarly journals Follitropin Delta as a State-of-the-Art Incorporated Companion for Assisted Reproductive Procedures: A Two Year Observational Study

Medicina ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 379
Author(s):  
Bogdan Doroftei ◽  
Ovidiu-Dumitru Ilie ◽  
Ana-Maria Dabuleanu ◽  
Roxana Diaconu ◽  
Radu Maftei ◽  
...  
Keyword(s):  
Observational Study ◽  
Ovarian Hyperstimulation Syndrome ◽  
Twin Pregnancy ◽  
Assisted Reproductive Technologies ◽  
State Of The Art ◽  
Follicle Stimulating Hormone ◽  
Exact Result ◽  
Reproductive Technologies ◽  
The Other ◽  
Ovarian Hyperstimulation

Background and objectives: The latest reports suggest that follitropin delta is a highly efficient recombinant human follicle-stimulating hormone (r-hFSH) that became a part of the current assisted reproductive technologies (ARTs). Therefore, the present study aims to assess a series of parameters (follicles, oocytes, and embryos) and further by the outcomes in women following the administration of follitropin delta. Materials and methods: This observational study included 205 women. They were aged between 21 and 43 years (mean 33.45) and an anti-Müllerian hormone (AMH) level ranging from 0.11 to 16.00 ng/dL (mean 2.89). Results: In accordance with the established methodology and following the centralization of data, a total of fifty-eight pregnancies (28.29%) were achieved; forty-five (36.88%) were achieved in women under 35 years and thirteen (15.66%) in women above 35 years. These figures are positively correlated with women’s age considering that the number of follicles >18 mm, oocytes fertilized and embryo(s) varies among groups. Regarding the interest parameters, we noted n = 1719 follicles > 18 mm, n = 1279 retrieved oocytes, and n = 677 embryos at day 3. On the other hand, the following figures have been registered in women above 35 years: 814–follicles > 18 mm, 612 oocytes retrieved and 301 embryos at day 3. During this study, we registered only three cases of abortions (n = 1–0.81% in women under 35 years and n = 2–2.40% in women above 35 years). Nine pregnancies (7.37%) were stopped from evolution in females under 35 years, and twelve pregnancies (n = 8–6.55% in women under 35 years, while n = 4 in women above 35 years) were unsuccessful. A twin pregnancy has been confirmed (1.20%) in women above 35 years, six ongoing pregnancies (4.91%) in those under 35 years, and two in both groups (one per group–n = 1–0.81%, and 1.20%–n = 1) in which we did not know the exact result were registered at the end of the established studied interval. However, there were also situations in which the treatment cause an over-reactivity or had no effect; n = 2 were non-responders, and n = 1 exhibited moderate ovarian hyperstimulation syndrome (OHSS). Conclusions: Based on our results, we strongly encourage the use of this recombinant gonadotropin on a much larger scale.

scholarly journals When does the use of individual patient data in network meta-analysis make a difference? A simulation study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Steve Kanters ◽  
Mohammad Ehsanul Karim ◽  
Kristian Thorlund ◽  
Aslam Anis ◽  
Nick Bansback
Keyword(s):  
Simulation Study ◽  
Treatment Effect ◽  
Mean Squared Error ◽  
Individual Patient Data ◽  
Meta Analysis ◽  
Model Performance ◽  
Patient Data ◽  
Meta Regression ◽  
Treatment Comparisons ◽  
The Impact

Abstract Background The use of individual patient data (IPD) in network meta-analyses (NMA) is rapidly growing. This study aimed to determine, through simulations, the impact of select factors on the validity and precision of NMA estimates when combining IPD and aggregate data (AgD) relative to using AgD only. Methods Three analysis strategies were compared via simulations: 1) AgD NMA without adjustments (AgD-NMA); 2) AgD NMA with meta-regression (AgD-NMA-MR); and 3) IPD-AgD NMA with meta-regression (IPD-NMA). We compared 108 parameter permutations: number of network nodes (3, 5 or 10); proportion of treatment comparisons informed by IPD (low, medium or high); equal size trials (2-armed with 200 patients per arm) or larger IPD trials (500 patients per arm); sparse or well-populated networks; and type of effect-modification (none, constant across treatment comparisons, or exchangeable). Data were generated over 200 simulations for each combination of parameters, each using linear regression with Normal distributions. To assess model performance and estimate validity, the mean squared error (MSE) and bias of treatment-effect and covariate estimates were collected. Standard errors (SE) and percentiles were used to compare estimate precision. Results Overall, IPD-NMA performed best in terms of validity and precision. The median MSE was lower in the IPD-NMA in 88 of 108 scenarios (similar results otherwise). On average, the IPD-NMA median MSE was 0.54 times the median using AgD-NMA-MR. Similarly, the SEs of the IPD-NMA treatment-effect estimates were 1/5 the size of AgD-NMA-MR SEs. The magnitude of superior validity and precision of using IPD-NMA varied across scenarios and was associated with the amount of IPD. Using IPD in small or sparse networks consistently led to improved validity and precision; however, in large/dense networks IPD tended to have negligible impact if too few IPD were included. Similar results also apply to the meta-regression coefficient estimates. Conclusions Our simulation study suggests that the use of IPD in NMA will considerably improve the validity and precision of estimates of treatment effect and regression coefficients in the most NMA IPD data-scenarios. However, IPD may not add meaningful validity and precision to NMAs of large and dense treatment networks when negligible IPD are used.

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