Evidence map›Paper›PMID 34632099›Full record

ArticleHealth science reports2021

Functional transcranial Doppler: Selection of methods for statistical analysis and representation of changes in flow velocity.

Stephan T Egger, Julio Bobes, Erich Seifritz, Stefan Vetter, Daniel Schuepbach

Open access · goldAbstract read
In one paragraph

Article in Health science reports, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.4field-weighted citation impact, top 34% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 3 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 3 institutions in 4 countries.

Stephan T EggerDepartment of Psychiatry, Psychotherapy and Psychosomatics University of Zürich, Faculty of Medicine, Psychiatric University Hospital of Zurich Zurich Switzerland.ORCID https://orcid.org/0000-0002-0314-4929
Julio BobesDepartment of Psychiatry, ISPA, INEUROPA, CIBERSAM University of Oviedo, Faculty of Medicine Oviedo Spain.
Erich SeifritzDepartment of Psychiatry, Psychotherapy and Psychosomatics University of Zürich, Faculty of Medicine, Psychiatric University Hospital of Zurich Zurich Switzerland.
Stefan VetterDepartment of Psychiatry, Psychotherapy and Psychosomatics University of Zürich, Faculty of Medicine, Psychiatric University Hospital of Zurich Zurich Switzerland.
Daniel SchuepbachDepartment of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg University of Heidelberg Heidelberg Germany.
Universidad de Oviedo · ESUniversity of Zurich · CHHeidelberg University · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionTranscranial Doppler (TCD) is a method used to study cerebral hemodynamics. In the majority of TCD studies, regression analysis and analysis of variance are the most frequently applied statistical methods. However, due to the dynamic and interdependent nature of flow velocity, nonparametric tests may allow for better statistical analysis and representation of results.

methodThe sample comprised 30 healthy participants, aged 33.87 ± 7.48 years; with 33% (n = 10) females. During a visuo-motor task, the mean flow velocity (MFV) in the middle cerebral artery (MCA) was measured using TCD. The MFV was converted to values relative to the resting state. The results obtained were analyzed using the general linear model (GLM) and the general additional model (GAM). The fit indices of both analysis methods were compared with each other.

resultsBoth MCAs showed a steady increase in MFV during the visuo-motor task, smoothly returning to resting state values. During the first 20 seconds of the visuo-motor task, the MFV increased by a factor of 1.06 ± 0.07 in the right-MCA and by a factor of 1.08 ± 0.07 in the left-MCA. GLM and GAM showed a statistically significant change in MFV (GLM:F(2, 3598) = 16.76,

conclusionsBoth the GLM and GAM yielded valid statistical models of MFV in the MCA in healthy subjects. However, the model using the GAM resulted in improved fit indices. The GAM's advantage becomes even clearer when the MFV curves are visualized; yielding a more realistic approach to brain hemodynamics, thus allowing for an improvement in the interpretation of the mathematical and statistical results. Our results demonstrate the utility of the GAM for the analysis and representation of hemodynamic parameters.

Indexed as

functional Transcranial Doppler (fTCD)general additional model (GAM)general linear model (GLM)healthy participantshemodynamicsstatistical analysis

Identifiers

PMID34632099
PMCPMC8493565
OpenAlexW3203827558

What OpenQuestion holds

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LicenceCC BY-NC
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.