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:

plot of chunk sri
  • Respiratory Complaints (8 items);
  • Physical Function (6 items);
  • Attendant Symptoms and Sleep (7 items);
  • Social Relationships (6 items);
  • Anxiety (5 items);
  • Psychological Well-Being (9 items);
  • Social Functioning (8 items).

Based on the sub scales, a total summary scale is calculated. All scales have a score range between 0 and 100 with higher scores indicating a better quality of life [2]. All items are scored on a 5-point Likert scale ranging from 1 (completely untrue) to 5 (always true). The majority of items need to be recoded (recoded value = 6 – raw value).

Scoring the SRI

Based on the SRI Scoring Manual, I have written the R-package srir for calculating the SRI scores.

Installation

The package is hosted on GitHub and may be installed using the following code:

devtools::install_github("nrkoehler/srir")
library(srir)

Functions and data

The core of srir is the function scoring_sri(). It must be applied to a data frame with the 49 SRI items and one id variable. Moreover, the package contains two data frames with simulated values. Unlike df.full, df.na has some missing values.

names(df.full)
##  [1] "id"     "sri.1"  "sri.2"  "sri.3"  "sri.4"  "sri.5"  "sri.6" 
##  [8] "sri.7"  "sri.8"  "sri.9"  "sri.10" "sri.11" "sri.12" "sri.13"
## [15] "sri.14" "sri.15" "sri.16" "sri.17" "sri.18" "sri.19" "sri.20"
## [22] "sri.21" "sri.22" "sri.23" "sri.24" "sri.25" "sri.26" "sri.27"
## [29] "sri.28" "sri.29" "sri.30" "sri.31" "sri.32" "sri.33" "sri.34"
## [36] "sri.35" "sri.36" "sri.37" "sri.38" "sri.39" "sri.40" "sri.41"
## [43] "sri.42" "sri.43" "sri.44" "sri.45" "sri.46" "sri.47" "sri.48"
## [50] "sri.49"
head(df.na[1:6])
##   id sri.1 sri.2 sri.3 sri.4 sri.5
## 1  1     1     2     1     5     4
## 2  2     5     3     5     3     2
## 3  3     2     2     4    NA     5
## 4  4    NA     3     2     4     4
## 5  5     3     4     3     5     2
## 6  6     2     2     2     3     4

Usage

When applied to a data frame, the function returns a data frame containing the SRI score values and an id variable.

df <- scoring_sri(df.full, id = 'id')
head(df)
##   id sri.rc sri.pf sri.as sri.sr sri.ax sri.wb sri.sf sri.ss
## 1  1   37.5   50.0   46.4   95.8     35   52.8   28.1   49.4
## 2  2   56.2   45.8   60.7   41.7     45   66.7   59.4   53.6
## 3  3   50.0   50.0   35.7   45.8     35   58.3   53.1   46.9
## 4  4   46.9   54.2   39.3   75.0     55   38.9   43.8   50.4
## 5  5   71.9   50.0   28.6   58.3     50   33.3   40.6   47.5
## 6  6   53.1   66.7   28.6   45.8     30   47.2   37.5   44.1

If no id variable is specified, a data frame containing the score values only is returned.

df <- scoring_sri(df.na)
head(df)
##   sri.rc sri.pf sri.as sri.sr sri.ax sri.wb sri.sf sri.ss
## 1   37.5   50.0   46.4   95.8   35.0   52.8   28.1   49.4
## 2   56.2   45.8   70.8   25.0   31.2   66.7   67.9   52.0
## 3   50.0   50.0   33.3   50.0   31.2   53.1   46.4   44.9
## 4   46.4     NA   37.5   75.0   68.8   38.9   42.9     NA
## 5   65.0   50.0   12.5   55.0   50.0   33.3   40.6   43.8
## 6   60.7   70.0   25.0   37.5   33.3   40.6   37.5   43.5

References

  1. Struik, Fransien M., Huib A.M. Kerstjens, Gerrie Bladder, Roy Sprooten, Marianne Zijnen, Jerryll Asin, Thys van der Molen, and Peter J. Wijkstra. 2013. “The Severe Respiratory Insufficiency Questionnaire Scored Best in the Assessment of Health-Related Quality of Life in Chronic Obstructive Pulmonary Disease.” Journal of Clinical Epidemiology 66 (10): 1166–74.

  2. Windisch, Wolfram, Klaus Freidel, Bernd Schucher, Hansjrg Baumann, Matthias Wiebel, Heinrich Matthys, and Franz Petermann. 2003. “The Severe Respiratory Insufficiency (SRI) Questionnaire a Specific Measure of Health-Related Quality of Life in Patients Receiving Home Mechanical Ventilation.” Journal of Clinical Epidemiology 56 (8): 752–59.

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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).
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