iglu (version 4.2.2)

active_percent: Calculate percentage of time CGM was active

Description

The function `active_percent` produces the

Usage

active_percent(data, dt0 = NULL, tz = "",
range_type = "automatic", ndays = 14, consistent_end_date = NULL)

Value

A tibble object with five columns: subject id, corresponding active_percent value, duration of measurement period in days, start date, and end date.

Arguments

data

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

dt0

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

tz

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.

range_type

range_type = "automatic". A character string indicating the type of range ('automatic' or 'manual').

ndays

ndays = 14. An integer specifying the number of days to consider in the calculation.

consistent_end_date

consistent_end_date = NULL. A Date object or NULL indicating a period end date to be used for every subject. Leaving this value NULL will result in the end date being unique to each subject.

Author

Pratik Patel, Irina Gaynanova

Details

The function `active_percent` produces a tibble object with values equal to the percentage of time the CGM was active, the total number of observed days, the start date, and the end date. For example, if a CGM's (5 min frequency) times were 0, 5, 10, 15 and glucose values were missing at time 5, then percentage of time the CGM was active is 75 The output columns correspond to the subject id, the percentage of time for which the CGM was active, the number of days of measurements, the start date and the end date of measurements. The output rows correspond to the subjects. The values of `active_percent` are always between 0

References

Danne et al. (2017) International Consensus on Use of Continuous Glucose Monitoring Diabetes Care 40 .1631-1640, tools:::Rd_expr_doi("10.2337/dc17-1600").

Examples

data(example_data_1_subject)

active_percent(example_data_1_subject)

data(example_data_5_subject)

active_percent(example_data_5_subject)
active_percent(example_data_5_subject, dt0 = 5, tz = 'GMT')