qlq_lmc21: Score the EORTC QLQ-LMC21 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-LMC21 Quality of Life Questionnaire

Description

Scores the European Organization for Research and Treatment of Cancer (EORTC) QLQ-LMC21 Colorectal Liver Cancer Module.

Usage

qlq_lmc21(df, items = NULL, keepNvalid = FALSE)

Arguments

df	A data frame containing responses to the 21 QLQ-LMC21 items, and possibly other variables.
items	A character vector with the QLQ-LMC21 item names, or a numeric vector indicating the column numbers of the QLQ-LMC21 items in df. If items is omitted, then qlq_lmc21 will assume that df contains ONLY the QLQ-LMC21 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 13 different scores from the EORTC QLQ-LMC21. Scores are calculated according to the official scoring algorithms from the EORTC.

In addition to the name of your data frame containing the QLQ-LMC21 item responses (df), you need to tell the function how to find the variables that correspond to the QLQ-LMC21 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 21 QLQ-LMC21 items in order starting with the 11th variable, then you could use items = 11:36.

2. The second way only applies if your data frame (df) contains ONLY the 21 variables corresponding to the 21 QLQ-LMC21 items, in order, with no other non-QLQ-LMC21 variables. In this case, you can just use the df argument and omit items.

Value

A data frame with all 13 of the QLQ-LMC21 scores is returned. Of the 13 scores, all 13 are Symptom Scales (see below). Of the 13 Symptom Scales, 9 are based on a single item each. 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)

• LMC_NP - Nutritional problems (from 2 items)

• LMC_FA - Fatigue (from 3 items)

• LMC_PA - Pain (from 3 items)

• LMC_EP - Emotional problems (from 4 items)

• LMC_WL - Weight loss (from 1 item)

• LMC_TA - Taste (from 1 item)

• LMC_DM - Dry mouth (from 1 item)

• LMC_SM - Sore mouth/tongue (from 1 item)

• LMC_PN - Peripheral neuropathy (from 1 item)

• LMC_JA - Jaundice (from 1 item)

• LMC_FR - Contact with friends (from 1 item)

• LMC_FE - Talking about feelings (from 1 item)

• LMC_SX - Sex life (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_lmc21 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.

References

Blazeby JM, Fayers P, Conroy T, et al. Validation of the EORTC QLQ-LCM21 Questionnaire for Assessment of Patient-Reported Outcomes During Treatment of Colorectal Liver Metastases. Br J Surg 96:291-298, 2009.

Kavadas V, Blazeby JM, et al. Development of an EORTC disease-specific quality of life questionnaire for use in patients with liver metastases from colorectal cancer. Eur J Cancer. 2003 Jun;39(9):1259-63.

Examples

## Not run: 
dat <- PROscorerTools::makeFakeData(n = 10, nitems = 21, prefix = "lmc", values = 1:4)
qlq_lmc21(dat, items = 1:21)

## End(Not run)

raybaser/PROscorer documentation built on Nov. 2, 2024, 11:52 p.m.