raw_GLIdiff {rspiro}

Convert z-scores back to raw diffusing capacity values using GLI (2017) equations

Description

This function takes z-scores based on the GLI (2017) equations, plus demographic data (age, height and gender), and converts them back into absolute diffusing capacity measurements (TLCO, KCO and VA).

Usage

raw_GLIdiff(
  age,
  height,
  gender = 1,
  TLCO = NULL,
  KCO = NULL,
  VA = NULL,
  SI = TRUE
)

Arguments

age

Age in years

height

Height in meters

gender

Gender (1 = male, 2 = female) or a factor with two levels (first = male). Default is 1.

TLCO

Transfer factor of the lung for carbon monoxide (z-score)

KCO

Transfer coefficient of the lung for carbon monoxide (z-score)

VA

Alveolar volume (z-score)

SI

(default TRUE) Use SI (mmol/min/kPa) or traditional (ml/min/mmHg) units?

Details

At least one of the diffusing capacity z-score arguments must be set (i.e. be non-NULL). Arguments age, height and gender must be vectors of length equal to the length of the z-score vector(s), or of length one, in which case their value is recycled. If any input vector is not of equal length, the function stops with an error.

Value

If only one diffusing capacity z-score argument is supplied, the function returns a numeric vector. If more are supplied, the function returns a data.frame with the same number of columns.

Examples

# Random data, 4 patients, one z-score parameter supplied (TLCO)
raw_GLIdiff(age=seq(25,40,5), height=c(1.8, 1.9, 1.75, 1.85),
      gender=c(2,1,2,1), TLCO=c(-1.2, -1.9, 0, 0.5))