Compute Rasch transformation for PROactive scores — rasch

This function provides the 0-100 Rasch scaled score of a given C-PPAC or D-PPAC raw score (based on: Garcia-Aymerich J, et al. Thorax 2021;0:1–11. doi: 10.1136/thoraxjnl-2020-214554).

Usage

rasch_transform(
  x,
  quest = c("C-PPAC", "D-PPAC"),
  score = c("difficulty", "quantity")
)

Arguments

x: A numeric value that is the difficulty score (between 0 and 40 for C-PPAC or 0 and 20 for D-PPAC) or the quantity score (between 0 and 15 for C-PPAC or 0 and 17 for D-PPAC) obtained using a PROactive questionnaire.
quest: A character value to indicate with which PROactive questionnaire the raw score has been obtained.
score: A character value.

Value

A numeric value.

Examples

rasch_transform(33, quest = "C-PPAC", score = "difficulty")
#> [1] 81