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Fehlende Werte bei Patienten-berichteten Endpunkten in einer Längsschnittstudie bei fortgeschrittenem und metastasiertem Krebs
Get PDFMissing patient-reported outcomes (PROs) are common in follow-up visits for longitudi-nal studies. However, the rates of missing values are relatively high in relation to health deterioration and premature death in patients with advanced stages of cancer. This study aims to investigate the rates and patterns of missing PROs data as well as to ex-plore the association between patient characteristics and time-to-dropout or time-to-death for a better understanding of how the missing data mechanism could be applied to missing PROs data in severely affected patients.
This is an exploratory study using data from the Oncological Social Care Project. Missing rates and missing data patterns were reported using cumulative numbers and rates. The competing-risk analysis, using Fine and Gray’s proportional sub-distribution hazards model, was performed to explore factors associated with time-to-dropout when considering death as a competing event. Additionally, a Cox regression model was used to explore factors associated with time-to-death.
A total of 362 patients were observed. The cumulative missing rate for assessing PROs was around 28% and 19%, caused by premature death and dropout, respectively. Being divorced or widowed (SHR=2.71; 95%CI: 1.12–6.56) and having poor social support (SHR=2.10; 95%CI: 1.01–4.35) were associated with early dropout. The presence of malignant neoplasm of pancreas cancer (HR = 2.48; 95%CI: 1.27–4.85) and a medium level of education (HR = 1.58; 95%CI: 1.02–2.45) were associated with premature death. Dropping out early from the study was associated with low baseline global health status/quality of life (GH/QoL) (SHR=1.14; 95%CI: 1.01–1.27) and low baseline role functioning, such as limited ability to do work or daily activities (SHR=1.10; 95%CI: 1.01–1.19). Furthermore, worsening scores of GH/QoL, functioning, and symptoms at baseline and at the last visit were associated with premature death.
In the advanced stages of cancer research, high rates of missing PROs data should be expected. The worsening of health-related quality of life (e.g., GH/QoL, physical functioning, fatigue scores) was associated with missing PROs data, suggesting that the missing data is not completely random. The investigation of patient characteristics as-sociated with missing data is also informative and a prerequisite for further proper analysis of the data.Fehlende von den Patienten berichteten Ergebnisse (patient-reported outcomes: PROs) sind bei Nachuntersuchungen im Rahmen von Langzeitstudien üblich. Die Raten fehlender Werte sind jedoch relativ hoch, wenn es um die Verschlechterung des Gesundheitszustands und den vorzeitigen Tod von Patienten in fortgeschrittenen Krebsstadien geht. Ziel dieser Studie ist es, die Raten und Muster fehlender PRO-Daten zu untersuchen sowie den Zusammenhang zwischen Patientenmerkmalen und der Zeit bis zum Abbruch bzw. bis zum Tod zu erforschen, um besser zu verstehen, wie der Mechanismus fehlender Daten auf fehlende PRO-Daten bei schwer betroffenen Patienten angewendet werden könnte.
Es handelt sich um eine explorative Studie, die Daten aus dem Oncological Social Care Project verwendet. Fehlende Raten und Muster fehlender Daten wurden anhand kumulativer Zahlen und Raten angegeben. Eine Analyse des konkurrierenden Risikos unter Verwendung des proportionalen Unterverteilungs-Hazards-Modells von Fine und Gray wurde durchgeführt, um Faktoren zu untersuchen, die mit der Zeit bis zum Abbruch in Verbindung stehen, wenn der Tod als konkurrierendes Risiko betrachtet wird. Zusätzlich wurde ein Cox-Regressionsmodell verwendet, um Faktoren zu untersuchen, die mit der Zeit bis zum Tod in Verbindung stehen.
Insgesamt wurden 362 Patienten beobachtet. Die kumulative Missingrate für die Bewertung der PROs lag bei 28% bzw. 19%, verursacht durch vorzeitigen Tod bzw. Drop-out. Geschieden oder verwitwet zu sein (SHR=2,71; 95%KI: 1,12 – 6,56) und geringe soziale Unterstützung (SHR=2,10; 95%KI: 1,01 – 4,35) waren mit einem frühen Abbruch verbunden. Das Vorhandensein einer bösartigen Neubildung der Pankreas (HR=2,48; 95%KI: 1,27 - 4,85) und ein mittleres Bildungsniveau (HR=1,58; 95%KI: 1,02 - 2,45) waren mit einem vorzeitigen Tod assoziiert. Ein vorzeitiger Abbruch aus der Studie war mit einem niedrigen Ausgangswert für den globalen Gesundheitszustand/die Lebensqualität (GH/QoL) (SHR=1,14; 95%KI: 1,01 - 1,27) und einem niedrigen Ausgangswert für die Rollenfunktion, wie z. B. einer eingeschränkten Fähigkeit zur Ausübung von Arbeit oder täglichen Aktivitäten (SHR=1.10; 95%KI: 1,01 - 1,19) assoziiert. Darüber hinaus war eine Verschlechterung der Werte für GH/QoL, Funktionsfähigkeit und Symptome zu Studienbeginn und bei der letzten Visite mit einem vorzeitigen Versterben assoziiert.
In den fortgeschrittenen Stadien der Krebsforschung sind hohe Raten an fehlenden PRO-Daten zu erwarten. Die Verschlechterung der gesundheitsbezogenen Lebensqualität (z. B. GH/QoL, körperlichen Funktionsfähigkeit, Müdigkeit) stand in Verbindung mit fehlenden PROs-Daten. Das bedeutet, dass der Mechanismus der fehlenden Daten nicht völlig zufällig ist. Die Untersuchung von Patientenmerkmalen, die mit fehlenden Daten in Verbindung stehen, ist aufschlussreich und eine Voraussetzung für die weitere korrekte Auswertung der Daten
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Serum anti-NMDA receptor antibodies are linked to memory impairment 12 months after stroke
No full textAbstract Patients suffering from strokes are at increased risk of developing post-stroke dementia. Serum anti-NMDA receptor autoantibodies (NMDAR1-abs) have been associated with unfavorable post-stroke outcomes. However, their effect on specific cognitive domains remains unclear. We used data from the prospective multicenter DZNE—mechanisms after stroke (DEMDAS) cohort, and measured NMDAR1-abs in serum at baseline. Cognitive function was assessed with a comprehensive neuropsychological test battery at 6- and 12-months follow-up. We employed crude and stepwise confounder adjusted linear and logistic regression models as well as generalized estimating equation models (GEE) to determine the relevance of NMDAR1-abs seropositivity on cognitive function after stroke. 10.2% (58/569) DEMDAS patients were NMDAR1-abs seropositive (IgM:n = 44/IgA:n = 21/IgG:n = 2). Seropositivity was not associated with global cognitive impairment after stroke. However, NMDAR1-abs seropositive patients performed lower in the memory domain (β adjusted = −0.11; 95%CI = −0.57 to −0.03) and were at increased risk for memory impairment (OR adjusted = 3.8; 95%CI = 1.33–10.82) compared to seronegative patients, 12 months after stroke. Further, NMDAR1-abs were linked to memory impairment over time in GEE from 6- to 12-months follow-up (OR adjusted = 2.41; 95%CI = 1.05–5.49). Our data suggests that NMDAR1-abs contribute to memory dysfunction 1 year after stroke while not affecting other cognitive subdomains. Hence, antineuronal autoimmunity may be involved in distinct mechanisms of post-stroke memory impairment. Clinical trial name and registration number : The Determinants of Dementia After Stroke (DEMDAS; study identifier on clinical trials.gov: NCT01334749
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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