EQ-5D data can be reported in a number of ways. Descriptive system responses provide information across the five EQ-5D dimensions, while value sets allow states to be converted into preference-based utility scores. Depending on the study objectives analyses may also focus on severity, distributional characteristics or changes in health over time.
The eq5d package provides tools for these common
reporting tasks. This vignette gives an overview of the reporting tools
available in the package and introduces the accompanying vignettes that
cover each area in more detail. Throughout the emphasis is on producing
clear reproducible summaries of EQ-5D data.
The methods implemented in these vignettes broadly follow the recommendations described by Devlin, Janssen and Parkin, which provides a comprehensive reference for analysing and reporting EQ-5D data.
The reporting functionality in eq5d is described across
a small set of complementary vignettes. New users may find it useful to
work through them in the following order:
Reporting EQ-5D Data
Provides an overview of the reporting tools available in
eq5d and explains how the different components fit
together.
Reporting the EQ-5D Descriptive System
Covers the structure of the descriptive system and how it can be
summarised and reported.
Reporting EQ-5D Severity and Distributional
Summaries
Describes severity measures, informativity metrics and summaries of
health state distributions.
Reporting EQ-5D Change Analysis
Covers methods for reporting longitudinal change, including
profile-based and comparative summaries.
Each vignette is self-contained, but together they provide a complete
guide to reporting EQ-5D data using eq5d.
An additional vignette is available for Mapping between EQ-5D-5L and EQ-5D-3L using the NICE Decision Support Unit (DSU) models.
eq5d provides functions for reporting several aspects of
EQ-5D data, including descriptive system responses, utility scores,
severity measures, distributional summaries and longitudinal change.
The package focusses on methods that are commonly used in EQ-5D analysis and reporting, providing standardised outputs that can be incorporated into reproducible analytical workflows.
A companion Shiny application provides an interactive interface to many of the same analytical methods, together with additional visualisations and exploratory summaries.
The remaining sections of this vignette briefly introduce the main reporting methods available in the package.
A common step in EQ-5D analysis is converting descriptive system responses into utility index scores.
When reporting utility index scores, an appropriate value set must be selected. Value sets map EQ-5D health states to utility values based on population preferences and may differ according to:
The choice of value set depends on the study context and any relevant
policy, methodological or clinical requirements. For this reason
eq5d does not assume a default value set. Instead, value
set selection is always made explicitly by the user.
Reports should always document the value set used, including the EQ-5D version, country and valuation method.
Available value sets can be listed using the valuesets()
function and filtered by version, valuation method and country.
For example, the following returns value sets available for France with associated references:
head(valuesets(country = "France", references = c("PubMed", "DOI")))
#> Version Type Country PubMed DOI Notes
#> 1 EQ-5D-3L DSU France NA <NA> <NA>
#> 2 EQ-5D-3L TTO France 21935715 10.1007/s10198-011-0351-x <NA>
#> 3 EQ-5D-5L CW France 22867780 10.1016/j.jval.2012.02.008 <NA>
#> 4 EQ-5D-5L DSU France NA <NA> <NA>
#> 5 EQ-5D-5L VT France 31912325 10.1007/s40273-019-00876-4 <NA>
#> 6 EQ-5D-3L RCW France 34452708 10.1016/j.jval.2021.03.009 van Hout (2021)Value sets can also be queried by valuation method:
head(valuesets(type = "VT", references = c("PubMed", "DOI")))
#> Version Type Country PubMed DOI
#> 1 EQ-5D-5L VT Australia 36720793 10.1007/s40273-023-01243-0
#> 2 EQ-5D-5L VT Belgium 35927410 10.1007/s41669-022-00353-3
#> 3 EQ-5D-5L VT Canada 26492214 10.1097/MLR.0000000000000447
#> 4 EQ-5D-5L VT China 28408009 10.1016/j.jval.2016.11.016
#> 5 EQ-5D-5L VT Denmark 33527304 10.1007/s40258-021-00639-3
#> 6 EQ-5D-5L VT Egypt 34786590 10.1007/s40273-021-01100-yFilters can be combined to identify value sets relevant to a particular analysis.
Response distributions for each EQ-5D dimension can be summarised
using descriptive_data() and presented using
table_descriptive().
For illustration, the example below uses a single group to produce an ungrouped descriptive table.
dat1 <- subset(dat, Group == "Group1")
dd <- descriptive_data(dat1, version = "3L", metric = "percent")
table_descriptive(dd)
#> Level MO SC UA PD AD
#> 1 1 43 48 22 6 57
#> 2 2 57 52 71 78 43
#> 3 3 0 0 7 16 0
#> 4 Total 100 100 100 100 100Detailed discussion of descriptive system reporting, including grouped summaries and table construction, is provided in Reporting the EQ-5D Descriptive System.
In addition to descriptive tables, EQ-5D data can be summarised using measures that describe the severity and distribution of observed health states.
For example, the package provides the Level Sum Score (LSS) and Level Frequency Score (LFS):
Additional functions support informativity measures, including Shannon entropy and evenness, as well as summaries of health state distributions such as the Health State Density Index (HSDI).
These measures can provide useful context for understanding the distribution of health outcomes within a population and are described in detail in Reporting EQ-5D Severity and Distributional Summaries.
The eq5d package includes tools for reporting changes in
EQ-5D health profiles over time. For illustration, the example below
constructs a simple paired dataset by treating the Group
variable as a pre/post indicator. This is purely for demonstration
purposes.
The Paretian Classification of Health Change (PCHC) provides a profile-based summary of individual change:
pchc_res <- pchc(
MO + SC + UA + PD + AD ~ Group | id,
data = dat_long,
version = "3L",
summary = TRUE
)
pchc_res
#> Number Percent
#> No change 14 14
#> Improve 59 59
#> Worsen 14 14
#> Mixed change 13 13
#> Total with problems 100 100
#> No problems 0 0The Probability of Superiority (PS) provides a complementary population-level summary of change:
ps_res <- ps(
MO + SC + UA + PD + AD ~ Group | id,
data = dat_long,
version = "3L"
)
ps_res
#> $MO
#> [1] 0.6
#>
#> $SC
#> [1] 0.62
#>
#> $UA
#> [1] 0.69
#>
#> $PD
#> [1] 0.66
#>
#> $AD
#> [1] 0.55Further details on these methods and their interpretation are provided in Reporting EQ-5D Change Analysis.
Visualisation can complement numerical summaries and reporting tables by helping to communicate patterns in EQ-5D data.
The package includes visualisation tools such as the Health Profile Grid (HPG) and Health State Density Curve (HSDC), which support the interpretation of change analyses and health-state distributions, respectively.
As with other outputs in eq5d, visualisations are most informative when considered alongside the underlying numerical summaries.
This vignette provides a high-level overview of the reporting tools
available in eq5d. Subsequent vignettes describe
descriptive system reporting, severity and distributional summaries and
longitudinal change analysis in greater detail.