Non-HDL cholesterol level

This function calculates a respondent's non-HDL cholesterol level by subtracting their HDL cholesterol level from their total cholesterol level. It first checks whether the input values lab_chol (total cholesterol) and lab_hdl (HDL cholesterol) are within valid ranges.

Usage

calculate_nonhdl(lab_chol, lab_hdl)

Arguments

lab_chol

numeric A numeric representing a respondent's total cholesterol level in mmol/L.

lab_hdl

numeric A numeric representing a respondent's HDL cholesterol level in mmol/L.

Value

numeric The calculated non-HDL cholesterol level (in mmol/L). If inputs are invalid or out of bounds, the function returns a tagged NA.

Details

The function calculates the non-HDL cholesterol level by subtracting the HDL cholesterol level from the total cholesterol level.

     **Missing Data Codes:**
     - `lab_chol`:
       - `99.96`: Valid skip. Handled as `haven::tagged_na("a")`.
       - `99.97-99.99`: Don't know, refusal, or not stated. Handled as `haven::tagged_na("b")`.
     - `lab_hdl`:
       - `9.96`: Valid skip. Handled as `haven::tagged_na("a")`.
       - `9.97-9.99`: Don't know, refusal, or not stated. Handled as `haven::tagged_na("b")`.

See also

categorize_nonhdl()

Examples

# Scalar usage: Single respondent
# Example: Respondent has total cholesterol of 5.0 mmol/L and HDL cholesterol of 1.5 mmol/L.
calculate_nonhdl(lab_chol = 5.0, lab_hdl = 1.5)
#> [1] 3.5
# Output: 3.5

# Example: Respondent has non-response values for cholesterol.
result <- calculate_nonhdl(lab_chol = 99.98, lab_hdl = 1.5)
result # Shows: NA
#> [1] NA
haven::is_tagged_na(result, "b") # Shows: TRUE (confirms it's tagged NA(b))
#> [1] TRUE
format(result, tag = TRUE) # Shows: "NA(b)" (displays the tag)
#> [1] "NA"

# Multiple respondents
calculate_nonhdl(lab_chol = c(5.0, 6.0, 7.0), lab_hdl = c(1.5, 1.0, 2.0))
#> [1] 3.5 5.0 5.0
# Returns: c(3.5, 5.0, 5.0)

# Database usage: Applied to survey datasets
# library(dplyr)
# dataset |>
#   mutate(non_hdl = calculate_nonhdl(lab_chol, lab_hdl))