zscore_JRS {rspiro}

Convert spirometric values to z-scores using JRS (2014) equations

Description

This function takes absolute spirometry measurements (FEV1, FVC, VC, FEV1/FVC) in lt plus demographic data (age, height and gender) and converts them to z-scores based on the JRS (Japanese Respiratory Society 2014) equations.

Usage

zscore_JRS(
  age,
  height,
  gender = 1,
  FEV1 = NULL,
  FVC = NULL,
  VC = NULL,
  FEV1FVC = 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.

FEV1

Forced Expiratory Volume in 1 second (lt)

FVC

Forced Vital Capacity (lt)

VC

Vital Capacity (lt)

FEV1FVC

FEV1 / FVC

Details

At least one of the spirometric measurement 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 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_JRS(age=seq(25,40,4), height=c(1.8, 1.9, 1.75, 1.85),
      gender=c(2,1,2,1), FEV1=c(3.5, 4, 3.6, 3.9))