LLN_NHANES3 {rspiro}

Calculate predicted values of spirometry parameters using NHANES III equations

Description

This function calculates LLNs (Lower Limits of Normal) for the various spirometry parameters, using the NHANES III equations. It accepts as input age, height, gender and ethnicity.

Usage

LLN_NHANES3(age, height, gender = 1, ethnicity = 1, param = "FEV1")

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 = Mexican-American). Default is 1.

param

A character vector, containing one of more of the following parameters (case insensitive): "FEV1", "FVC", "FEV1FVC", "PEF", "FEF2575", "FEV6", "FEV1FEV6"

Details

Arguments age, height, gender and ethnicity are vectors of equal length, or of length one, in which case the value is recycled; if the four vectors are not of equal length, the function stops with an error.

Value

If param has length one, the function returns a numeric vector. If param has length >1, it returns a data.frame with length(param) columns.

Examples

# Find LLN of FEV1 and FVC for Caucasian women aged 20 to 70 and with a height of 1.70 meters.
LLN_NHANES3(20:70, 1.7, 2, param=c("FEV1","FVC"))