redcapAPI (version 2.8.0)

parseBranchingLogic: Parse Branching Logic

Description

Branching logic from the REDCap Data Dictionary is parsed into R Code and returned as expressions. These can be evaluated if desired and allow the user to determine if missing values are truly missing or not required because the branching logic prevented the variable from being presented.

Usage

parseBranchingLogic(l)

Value

Returns a list of unevaluated expressions.

Arguments

l

A vector of REDCap branching logic statements. These are usually passed as the vector meta_data$branching_logic.

Details

For a study, I was asked to identify which subjects had missing values so that remaining data could be collected. The initial pass of is.na produced a lot of subjects missing values where there was no need to collect data because they did not qualify for some variables in the branching logic. Parsing the logic allowed me to determine which values we expected to be missing and narrow the search to just those subjects with legitimately missing values.

The utility of this function is limited to simple logic where all of the data exist within the same row. Any complex statements using events will result in a failure.

See Also

missingSummary()

Examples

if (FALSE) {
parseBranchingLogic("[age] > 30")
parseBranchingLogic("[dropdown_test] = 'd'")
parseBranchingLogic(c("[age] > 30", 
                      "[dropdown_test] = 'd'"))
}