qlq_cx24: Score the EORTC QLQ-CX24 Quality of Life Questionnaire

In raybaser/PROscorer: Functions to Score Commonly-Used Patient-Reported Outcome (PRO) Measures and Other Psychometric Instruments

Score the EORTC QLQ-CX24 Quality of Life Questionnaire

Description

Scores the European Organization for Research and Treatment of Cancer (EORTC) QLQ-CX24 Cervical Cancer Module.

Usage

qlq_cx24(df, items = NULL, keepNvalid = FALSE)

Arguments

df	A data frame containing responses to the 24 QLQ-CX24 items, and possibly other variables.
items	A character vector with the QLQ-CX24 item names, or a numeric vector indicating the column numbers of the QLQ-CX24 items in df. If items is omitted, then qlq_cx24 will assume that df contains ONLY the QLQ-CX24 items and no other variables. See Details for more information.
keepNvalid	Logical, whether to return variables containing the number of valid, non-missing items on each scale for each respondent should be returned in the data frame with the scale scores. The default is FALSE. Set to TRUE to return these variables, which will be named "scalename_N" (e.g., QL_N). Most users should omit this argument entirely. This argument might be removed from future versions of the package, so please let me know if you think this argument useful and would rather it remain a part of the function.

Details

This function returns a total of 9 different scores from the EORTC QLQ-CX24. Scores are calculated according to the official scoring algorithms from the EORTC.

In addition to the name of your data frame containing the QLQ-CX24 item responses (df), you need to tell the function how to find the variables that correspond to the QLQ-CX24 items in df. You can do this in 1 of 2 ways:

1. The first way is to manually provide the item names or locations using the items argument. For example, if your first 10 variables in df contain demographics, followed by the 24 QLQ-CX24 items in order starting with the 11th variable, then you could use items = 11:34.

2. The second way only applies if your data frame (df) contains ONLY the 24 variables corresponding to the 24 QLQ-CX24 items, in order, with no other non-QLQ-CX24 variables. In this case, you can just use the df argument and omit items.

Value

A data frame with all 9 of the QLQ-CX24 scores is returned. Of the 9 scores, 7 are Symptom Scales and 2 are Functional Scales (see below). Of the 9 scores, only 3 are based on multiple items (the first 3 Symptom Scales), and the other 6 scores are each based on a single item. All scores are scaled to range from 0-100, even scores based on single items. Be aware that these single-item scales still have only 4 possible values, even though they are transformed to range from 0-100. The scale names and numbers of items are listed below.

Symptom Scales (higher is more symptoms, worse functioning)

• CX_SE - Symptom Experience (from 11 items)

• CX_BI - Body Image (from 3 items)

• CX_SV - Sexual/Vaginal Functioning (from 4 items)

• CX_LY - Lymphoedema (from 1 item)

• CX_PN - Peripheral Neuropathy (from 1 item)

• CX_MS - Menopausal Symptoms (from 1 item)

• CX_SXW - Sexual Worry (from 1 item)

Functional Scales (higher is better functioning)

• CX_SXA - Sexual Activity (from 1 item)

• CX_SXE - Sexual Enjoyment (from 1 item)

Optionally, the data frame can additionally have variables containing the number of valid item responses on each scale for each respondent (if keepNvalid = TRUE, but this option might be removed in future package updates).

How Missing Data is Handled

The qlq_cx24 function will calculate the scale scores as long as at least half of the items on the given scale have valid, non-missing item responses. Scores calculated in the presence of missing items are pro-rated so that their theoretical minimum and maximum values are identical to those from scores calculated from complete data.

Note

Note that the QLQ-CX24 instructs respondents to answer the last 5 questions on the instrument only if they have been sexually active during the past 4 weeks. These 5 items include all 4 items on the Sexual/Vaginal Functioning symptom scale and the 1 item on the Sexual Enjoyment functional scale. Because of this, when the QLQ-CX24 is scored correctly, it is normal for a large number of respondents to have missing values for the Sexual/Vaginal Functioning and Sexual Enjoyment scores. This is due to those respondents skipping those questions because they were not sexually active during the 4 weeks before completing the questionnaire.

References

Greimel E, Kuljanic Vlasic K, Waldenstrom AC et al. on behalf of the EORTC Quality of Life Group. The European Organization for Research and Treatment of Cancer (EORTC) Quality-of-Life questionnaire cervical cancer module - EORTC QLQ-CX24. Cancer 107 (8): 1812-1822, 2006.

Examples

## Not run: 
dat <- PROscorerTools::makeFakeData(n = 10, nitems = 24, prefix = "cx", values = 1:4)
qlq_cx24(dat, items = 1:24)

## End(Not run)

raybaser/PROscorer documentation built on Oct. 17, 2023, 8:48 p.m.