# LLN_NHANES3: Calculate predicted values of spirometry parameters using... In rspiro: Implementation of Spirometry 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

 `1` ```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

 ```1 2``` ```# 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")) ```

rspiro documentation built on March 26, 2020, 5:10 p.m.