derive_var_bcvacritxfl_util {admiralophtha}

Add CRITx/CRITxFL pair to BCVA dataset

Description

Helper function for derive_var_bcvacritxfl() that adds a criterion variable CRITx and its corresponding flag CRITxFL to a dataset containing BCVA records

Usage

derive_var_bcvacritxfl_util(
  dataset,
  crit_var,
  critx_text,
  critxfl_cond,
  counter,
  bcva_range = NULL,
  bcva_uplim = NULL,
  bcva_lowlim = NULL
)

Arguments

dataset

Input dataset (usually ADBCVA).

crit_var

Variable with respect to which CRITx/CRITxFL are derived (usually CHG or AVAL).

critx_text

String containing the text for CRITx variable.

critxfl_cond

String containing R code detailing the criterion to be satisfied for CRITxFL variable to be equal to "Y".

counter

Integer detailing the value of x to use in CRITxFL.

bcva_range

Numeric vector of length two detailing lower and upper change in BCVA limits (bcva_range will be called in critxfl_cond if the criterion stipulates that change in BCVA lie inside some range).

bcva_uplim

Numeric value detailing highest change in BCVA limit (bcva_uplim will be called in critxfl_cond if the criterion stipulates that change in BCVA lie below some upper limit).

bcva_lowlim

Numeric value detailing lowest change in BCVA limit (bcva_lowlim will be called in critxfl_cond if the criterion stipulates that change in BCVA lie above some lower limit).

Details

The criterion for change in BCVA in CRITxFL can be of three types: (1) value lies within some range; ⁠a <= crit_var <= b⁠; (2) value is below some upper limit; crit_var <= a; (3) value is above some lower limit; b <= crit_var. For (1), bcva_range must be specified to this function; for (2), bcva_uplim; for (3) bcva_lowlim. It is necessary to supply at least one of these three arguments. NOTE: if crit_var is equal to NA, then the resulting criterion flag is also marked as NA.

Value

The input BCVA dataset with additional columns CRITx, CRITxFL.

Author(s)

Edoardo Mancini