Author Archives: norbert

About norbert

Biometrician at Clinical Trial Centre, Leipzig University (GER), with degrees in sociology (MA) and public health (MPH).

Analyse der DFG Fachkollegienwahl 2015 — Teil I

Die Deutsche Forschungsgemeinschaft (DFG) ist die europaweit größte Forschungsförderungsorganisation mit einem Jahresetat von aktuell etwa 3 Milliarden Euro (2016). Die Aufgabe der DFG besteht in der Auswahl und Finanzierung wissenschaftlicher Forschungsvorhaben an Hochschulen und Forschungsinstituten. Laut DFG werden eingereichte Förderanträge … Continue reading

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How to draw a CONSORT flow diagram using R and GraphViz

Intro The acronym CONSORT stands for “Consolidated Standards of Reporting Trials”. The CONSORT statement is published by the CONSORT group and gives recommendations aiming to improve the quality of reports of randomized clinical trials. Besides a 25 item checklist, the … Continue reading

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How to Assign Variable Labels in R

Intro Defining variable labels is a useful way to describe and document datasets. Unlike SPSS, which makes it very easy to define variable labels using the data editor, base R doesn't provide any function to define variable labels (as far … Continue reading

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Multiple Imputations of missing values — ein Erfahrungsbericht

Intro In der Forschungspraxis werden Datenpunkte mit fehlenden Werten oft von der Analyse ausgeschlossen oder durch einen zentralen Lageparameter (Mittelwert, Median) ersetzt. Als Alternative dazu hat sich das Verfahren der Multiplen Imputation etabliert, welches in diesem Beitrag erklärt wird. Die … Continue reading

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Scoring the St George’s Respiratory Questionnaire (SGRQ) using R

Background The St George's Respiratory Questionnaire (SGRQ) is an instrument for the measuring of Health-Related Quality-of-Life in patients with diseases of airways obstruction. The SGRQ contains 50 items covering three domains: Symptoms (8 items), Activity (16 items), and Impacts (26 … Continue reading

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Scoring the Severe Respiratory Insufficiency Questionnaire (SRI) using R

Background The SRI is a multidimensional general health questionnaire “to assess HRQL in patients with chronic respiratory failure due to various underlying diseases” [1]. Based on 49 items, seven sub scales addressing the following domains are calculated: Respiratory Complaints (8 … Continue reading

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How to fix problems after updating to R 3.4.1 on Linux Mint 18.1 / Ubuntu 16.04

The Problem After updating R to version 3.4.1 (“Single Candle”) on Linux Mint 18.1, RStudio could neither find my installed R packages nor was it possible to install R packages into some other directory. The Solution Fortunately, this problem could … Continue reading

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