iglu (version 4.2.2)

plot_roc: Plot time series of glucose colored by rate of change

Description

The function plot_roc produces a time series plot of glucose values colored by categorized rate of change values

Usage

plot_roc(data, subjects = NULL, timelag = 15, dt0 = NULL, inter_gap = 45, tz = "")

Value

A time series of glucose values colored by ROC categories per subject

Arguments

data

DataFrame object with column names "id", "time", and "gl".

subjects

String or list of strings corresponding to subject names in 'id' column of data. Default is all subjects.

timelag

Integer indicating the time period (# minutes) over which rate of change is calculated. Default is 15, e.g. rate of change is the change in glucose over the past 15 minutes divided by 15.

dt0

The time frequency for interpolation in minutes, the default will match the CGM meter's frequency (e.g. 5 min for Dexcom).

inter_gap

The maximum allowable gap (in minutes) for interpolation. The values will not be interpolated between the glucose measurements that are more than inter_gap minutes apart. The default value is 45 min.

tz

A character string specifying the time zone to be used. System-specific (see as.POSIXct), but " " is the current time zone, and "GMT" is UTC (Universal Time, Coordinated). Invalid values are most commonly treated as UTC, on some platforms with a warning.

Author

Elizabeth Chun, David Buchanan

Details

For the default, a time series is produced for each subject in which the glucose values are plotted and colored by ROC categories defined as follows. The breaks for the categories are: c(-Inf, -3, -2, -1, 1, 2, 3, Inf) where the glucose is in mg/dl and the ROC values are in mg/dl/min. A ROC of -5 mg/dl/min will thus be placed in the first category and colored accordingly. The breaks for the categories come from the reference paper below.

References

Klonoff, D. C., & Kerr, D. (2017) A Simplified Approach Using Rate of Change Arrows to Adjust Insulin With Real-Time Continuous Glucose Monitoring. Journal of Diabetes Science and Technology 11(6) 1063-1069, tools:::Rd_expr_doi("10.1177/1932296817723260").

Examples

data(example_data_1_subject)
plot_roc(example_data_1_subject)

data(example_data_5_subject)
plot_roc(example_data_5_subject, subjects = 'Subject 5')