The function lbgi produces LBGI 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 LBGI value is returned. If a vector of glucose values is passed, then a tibble object with just the LBGI 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 LBGI values is returned. NA glucose values are omitted from the calculation of the LBGI.
LBGI is calculated by \(1/n * \sum (10 * fbg_i ^2)\), where \(fbg_i = min(0, 1.509 * (log(G_i)^{1.084} - 5.381)\), G_i is the ith Glucose measurement for a subject, and n is the total number of measurements for that subject.
References
Kovatchev et al. (2006) Evaluation of a New Measure of Blood Glucose Variability in, Diabetes Diabetes care 29 .2433-2438, doi:10.2337/dc06-1085 .
Examples
data(example_data_1_subject)
lbgi(example_data_1_subject)
#> # A tibble: 1 × 2
#> id LBGI
#> <fct> <dbl>
#> 1 Subject 1 0.432
data(example_data_5_subject)
lbgi(example_data_5_subject)
#> # A tibble: 5 × 2
#> id LBGI
#> <fct> <dbl>
#> 1 Subject 1 0.432
#> 2 Subject 2 0.00464
#> 3 Subject 3 0.142
#> 4 Subject 4 0.356
#> 5 Subject 5 0.195