epicmodel_steplist: Steplist objects

In epicmodel: Causal Modeling in Epidemiology

Steplist objects

Description

The S3 classes epicmodel_steplist and epicmodel_steplist_checked store the input information for SCC model creation. They are created from the Steplist Creator shiny app, which can be launched with launch_steplist_creator().

new_steplist(), validate_steplist(), and empty_steplist() define the S3 class.

print() prints a summary of the steplist entries in the console.

summary() prints a list of steps sorted by type of step in the console.

plot() renders a graph of the complete network of mechanisms in the RStudio Viewer.

Usage

new_steplist(x = list())

validate_steplist(x)

empty_steplist()

## S3 method for class 'epicmodel_steplist'
print(x, ...)

## S3 method for class 'epicmodel_steplist_checked'
print(x, ...)

## S3 method for class 'epicmodel_steplist'
summary(object, ...)

## S3 method for class 'epicmodel_steplist_checked'
summary(object, ...)

## S3 method for class 'epicmodel_steplist'
plot(x, ...)

## S3 method for class 'epicmodel_steplist_checked'
plot(x, modules = TRUE, module_colors = NULL, render = TRUE, ...)

Arguments

x	x is used in several functions: new_steplist(): A list to be converted to class epicmodel_steplist. validate_steplist(): An object of class epicmodel_steplist or epicmodel_steplist_checked to be validated. print.epicmodel_steplist(): An object of class epicmodel_steplist. print.epicmodel_steplist_checked(): An object of class epicmodel_steplist_checked. plot.epicmodel_steplist(): An object of class epicmodel_steplist. plot.epicmodel_steplist_checked(): An object of class epicmodel_steplist_checked.
...	Additional arguments for generics print(), summary(), and plot().
object	For summary.epicmodel_steplist(), an object of class epicmodel_steplist. For summary.epicmodel_steplist_checked(), an object of class epicmodel_steplist_checked.
modules	For plot.epicmodel_steplist_checked, TRUE (default) or FALSE, indicating if nodes in the same module should be colored equally (TRUE) or if all nodes have white background (FALSE). Colors are only applied, if modules have actually been specified in the epicmodel_steplist.
module_colors	For plot.epicmodel_steplist_checked, if nodes are colored by module, colors can be provided via this argument. Colors must be provided as a character vector. Both named colors and hexadecimal color codes are allowed. The function has 8 colors stored internally. If module_colors = NULL (default), these colors are used. If the model has more than 8 modules, module_colors must be specified. If more colors than necessary are specified, the function takes as many as necessary from the start of the vector.
render	For plot.epicmodel_steplist_checked, if TRUE (default), graph is directly rendered. IF FALSE, the output contains the non-rendered graph.

Details

epicmodel_steplist objects

epicmodel_steplist objects are lists containing 8 data.frames. These data.frames are described below:

what

A list of subjects and objects (WHAT segments) appearing in the step descriptions, e.g., cells, interleukins, symptoms, etc., with the following variables:

• id_what: Automatically created ID for WHAT segments. Starts with "a" followed by a number, e.g., a1. Used in creating automatic step IDs.

• key_what: Keyword describing the WHAT segment. Used in steplist_creator shiny app dropdown menus.

• desc_what: Text used in step descripiton.

• plural_what: Indicates if plural (1) or singular (0) version of the DOES description should be used, if this WHAT segment is used as subject, i.e., WHAT segment before the DOES segment.

does

A list of actions or verbs (DOES segments), with which the WHAT segments interact, e.g., is present, produce, migrate, exposed to, with the following variables:

• id_does: Automatically created ID for DOES segments. Starts with "d" followed by a number, e.g., d1. Used in creating automatic step IDs.

• key_does: Keyword describing the DOES segment. Used in steplist_creator shiny app dropdown menus.

• subject_singular_does: Description used if subject (WHAT segment in front) has been specified as singular (plural_what=0).

• subject_plural_does: Description used if subject (WHAT segment in front) has been specified as plural (plural_what=1).

• no_subject_does: Description used if no subject (WHAT segment in front) has been specified.

• then_object_does: Indicates if the object for this DOES segment is a WHAT segment (0) or a THEN statement (1).

where

A list of locations (WHERE segments), where the specified actions take place, e.g., in the airways, with the following variables:

• id_where: Automatically created ID for WHERE segments. Starts with "e" followed by a number, e.g., e1. Used in creating automatic step IDs.

• key_where: Keyword describing the WHERE segment. Used in steplist_creator shiny app dropdown menus.

• desc_where: Text used in step descripiton. Please include the corresponding preposition, e.g., 'in', 'into', 'on', etc.

then

A list of combinations of WHAT, DOES and WHERE segments (THEN statements). A THEN statement can contain up to 4 segments: WHAT (subject), DOES, WHAT (object), WHERE. Not all 4 of them need to be specified. For some DOES segments, the corresponding object is not a WHAT segment but a THEN statement (see then_object_does). In general, all combinations are possible, although only DOES, only WHERE, and WHAT WHAT do not make a lot of sense. then exists to store the THEN statements that are later used in IF and IFNOT conditions. It contains the following variables:

• id_then: Automatically created ID based on segment IDs, e.g., a4, a1d5a15e9, d2a3.

• desc_then: Automatically created description based on segment descriptions.

module

Modules are groups, into which the steps are sorted, e.g., immune system, lung, etc., as it is sometimes of interest to see which groups are involved in the sufficient causes. It contains the following variables:

• id_module: Automatically created ID for modules. Starts with "m" followed by a number, e.g., m1.

• key_module: Keyword describing the module.

• desc_module: Module description.

step

Main table of interest and the one further processed to create sufficient-component cause models. It contains the following variables:

• id_step: Automatically created step ID based on IDs of included THEN statements, e.g., IFd6a10IFNOTd6a18+d1a8THENa11d3a12.

• desc_step: Automatically created step description based on descriptions of included THEN statements.

• end_step: Indicator variable that describes if this step is at the end of a certain sub-mechanism, e.g., symptom x occured.

• module_step: Module, i.e., group, into which this step has been sorted.

• note_step: Additional notes that are important for future users, e.g., if there are conflicting results or if the result is from a mouse model.

• ref_step: References on which this step is based.

icc

ICC is short for incompatibel component causes. It contains pairs of component causes, i.e., steps without IF or IFNOT condition, that are not compatible with each other, i.e., cannot appear in the same sufficient cause. It contains the following variables:

• id_icc: Automatically created ID for ICC pairs. Starts with "i" followed by a number, e.g., i1.

• id1: Step ID of first component cause.

• id2: Step ID of second component cause.

• desc1: Step description of first component cause.

• desc2: Step description of second component cause.

outc

A list that contains conditions under which the outcome of interest is assumed to occur. Each line might contain one or more THEN statements, that have been marked as end steps by setting step$end_step to 1. If more than one THEN statement is selected, they are combined with AND logic. All lines in this table are combined with OR logic, i.e., any of the specified conditions is assumed to represent outcome occurrence. The table contains the following variables:

• id_outc: Automatically created ID for outcome definitions as a combination of the THEN statement IDs connected by '+'.

• desc_outc: Automatically created description for the outcome definitions as a combination of the THEN statement descriptions.

epicmodel_steplist_checked objects

Before using epicmodel_steplist object for SCC model creation in create_scc(), they need to be checked for any structures that might make SCC model creation impossible. Checking is performed by check_steplist() and if successful, the returned object is of type epicmodel_steplist_checked. When changing the steplist in the Steplist Creator shiny app or by functions remove_all_modules(), remove_na(), or remove_segment(), the steplist is "un-checked" and returned as class epicmodel_steplist. Apart from that, both classes have similar structure, which can be validated by validate_steplist().

Value

• new_steplist(): An object of class epicmodel_steplist.

• validate_steplist(): An object of class epicmodel_steplist or epicmodel_steplist_checked, that has been checked to have the correct structure.

• empty_steplist(): An empty object of class epicmodel_steplist object with correct structure.

• print.epicmodel_steplist(): Prints the number of entries in each data.frame in the console and the information that the steplist is unchecked.

• print.epicmodel_steplist_checked(): Same as print.epicmodel_steplist() but with the information the the steplist has been checked successfully.

• summary.epicmodel_steplist(): Prints an allert that the steplist needs to be checked with check_steplist() before using summary().

• summary.epicmodel_steplist_checked(): Prints a list of steps by type of step in the console.

• plot.epicmodel_steplist(): Prints an allert that the steplist needs to be checked with check_steplist() before using plot().

• plot.epicmodel_steplist_checked(): Prints a graph of the complete network of mechanisms in the RStudio Viewer and the corresponding legend in the console.

Examples

# Create steplists in the Steplist Creator `shiny` app
if(interactive()){
launch_steplist_creator()
}

# Download the steplist from the `shiny` app
# Load the steplist into R
path <- system.file("extdata", "steplist_rain.rds", package = "epicmodel")
steplist <- readRDS(path)

# new_steplist(), validate_steplist(), and empty_steplist() are used in the `shiny` app
# nonetheless, you can check steplist structures with validate_steplist()
validate_steplist(steplist)

# print() provides a summary of steplist entries and if it's checked or unchecked
print(steplist)

# Check steplist before using `summary()` and `plot()`
steplist_checked <- check_steplist(steplist)
summary(steplist_checked)
plot(steplist_checked)

epicmodel documentation built on April 12, 2025, 1:59 a.m.