zscore_GLI: Convert spirometric values to z-scores using GLI-2012...

In rspiro: Implementation of Spirometry Equations

Convert spirometric values to z-scores using GLI-2012 equations

Description

This function takes absolute spirometry measurements (FEV1, FVC, etc) in lt plus demographic data (age, height, gender and ethnicity) and converts them to z-scores based on the GLI-2012 equations.

Usage

zscore_GLI(
  age,
  height,
  gender = 1,
  ethnicity = 1,
  FEV1 = NULL,
  FVC = NULL,
  FEV1FVC = NULL,
  FEF2575 = NULL,
  FEF75 = NULL,
  FEV075 = NULL,
  FEV075FVC = NULL
)

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.
ethnicity	Ethnicity (1 = Caucasian, 2 = African-American, 3 = NE Asian, 4 = SE Asian, 5 = Other/mixed). Default is 1.
FEV1	Forced Expiratory Volume in 1 second (lt)
FVC	Forced Vital Capacity (lt)
FEV1FVC	FEV1 / FVC
FEF2575	Forced Expiratory Flow between 25% and 75% of FVC (lt/s)
FEF75	Forced Expiratory Flow at 75% of FVC (lt/s)
FEV075	Forced Expiratory Volume in 0.75 sec (lt)
FEV075FVC	FEV0.75 / FVC

Details

At least one of the spirometric measurement arguments must be set (i.e. be non-NULL). Arguments age, height, gender and ethnicity must be vectors of length equal to the length of the spirometric measurement 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 spirometry 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 parameter supplied (FEV1)
zscore_GLI(age=seq(25,40,4), height=c(1.8, 1.9, 1.75, 1.85),
      gender=c(2,1,2,1), ethnicity=rep(1,4), FEV1=c(3.5, 4, 3.6, 3.9))

rspiro documentation built on Aug. 7, 2023, 5:06 p.m.