The function grade produces GRADE score values in a tibble object.
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 \(1/n * \sum [425 * (log(log(G_i / 18)) + .16)^2]\) Where \(G_i\) is the ith 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, doi:10.1111/j.1464-5491.2007.02119.x .
Examples
data(example_data_1_subject)
grade(example_data_1_subject)
#> # A tibble: 1 × 2
#> id GRADE
#> <fct> <dbl>
#> 1 Subject 1 3.47
data(example_data_5_subject)
grade(example_data_5_subject)
#> # A tibble: 5 × 2
#> id GRADE
#> <fct> <dbl>
#> 1 Subject 1 3.47
#> 2 Subject 2 15.8
#> 3 Subject 3 7.26
#> 4 Subject 4 4.16
#> 5 Subject 5 10.1