iglu (version 3.0.0)

grade: Calculate mean GRADE score

Description

The function grade produces GRADE score values in a tibble object.

Usage

grade(data)

Arguments

data

DataFrame object with column names "id", "time", and "gl", or numeric vector of glucose values.

Value

If a data.frame object is passed, then a tibble object with two columns: subject id and corresponding GRADE value is returned. If a vector of glucose values is passed, then a tibble object with just the GRADE value is returned. as.numeric() can be wrapped around the latter to output just a numeric value.

Details

A tibble object with 1 row for each subject, a column for subject id and a column for GRADE values is returned. NA glucose values are omitted from the calculation of the GRADE.

GRADE score is calculated by \(1/n * \sum [425 * (log(log(BG_i / 18)) + .16)^2]\) Where \(BG_i\) is the ith Blood Glucose measurement and n is the total number of measurements.

References

Hill et al. (2007): A method for assessing quality of control from glucose profiles Diabetic Medicine 24 .753-758, 10.1111/j.1464-5491.2007.02119.x.

Examples

# NOT RUN {
data(example_data_1_subject)
grade(example_data_1_subject)

data(example_data_5_subject)
grade(example_data_5_subject)

# }