Author Archives: norbert

About norbert

I am post doc at the Department of Medical Psychology and Sociology, Leipzig University (GER), with degrees in sociology (MA) and public health (MPH).

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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How to calculate Odds Ratios in Case-Control Studies using R

Intro In June 2017 I've started working at the Clinical Trial Centre Leipzig at Leipzig University. Since my knowledge in statistics is rather poor, my employer offered me to attend some seminars in Medical Biometry at the University of Heidelberg. … Continue reading

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How to parse Citavi files using R

Intro In academic writing, the use of reference management software has become essential. A couple of years ago, I started using the free open-source software Zotero. However, most of my workmates at Leipzig University work with Citavi, a commercial software … Continue reading

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