Censor dates in line list

Censor <Date> columns in line list output from sim_linelist() to a specified time interval.

This function is similar to incidence2::incidence() but does not aggregate events into an <incidence2> object, instead it returns the same line list <data.frame> as input but with modified event dates.

Usage

censor_linelist(
  linelist,
  interval,
  reporting_artefact = c("none", "weekend_effects"),
  offset = min(linelist$date_onset, na.rm = TRUE)
)

Arguments

linelist

Line list <data.frame> output from sim_linelist().

interval

An integer or character string for the size of the time interval for censoring. Valid character options are:

• "daily

• "weekly"

• "epiweek"

• "montly"

• "yearly"

See details for information of the date/period objects that are returned for each interval type.

reporting_artefact

A character string, either "none" (default) or "weekend_effect". By default none of the dates are altered in other ways during censoring, however if reporting_artefact = "weekend_effect" then all the dates in the $date_reporting column that fall on a weekend are shifted to the following Monday. This artefact is commonly referred to as the "weekend effect" (see doi:10.1186/s13104-025-07145-y ).

offset

An integer or <Date> for the value to start counting the period from (0 is the start of the Unix epoch). Only applicable if interval is specified as an integer.

Default date used to start counting from for the <grates_period> is the earliest symptom onset date ($date_onset). See grates::as_period() for more information.

If setting reporting_artefact = "weekend_effects" the period may start or end on a weekend.

Value

A line list <data.frame>.

Details

The line list columns that contain <Date> objects are stored at double point precision by default. In other words, they are not integer values, so can be part way through a day. The exact numeric value of the <Date> can be seen if you unclass() it.

Censoring line list dates reduces the time precision (window) of the event. Often dates of events, such as symptom onset or hospital admission are only known to the nearest day, not hour or minute. Other events may be more coarsely censored, for example to the nearest week or month. censor_linelist() converts the exact double point precision event <Date> to the time interval specified.

Depending on the interval specified, the date columns will be returned as different objects. Here is a list of the valid input interval and the resulting class of the date column.

• integer -> <grates_period> (see grates::as_period())

• "daily" -> <Date> (see Date)

• "weekly" -> <grates_isoweek> (see grates::as_isoweek())

• "epiweek" -> <grates_epiweek> (see grates::as_epiweek())

• "monthly" -> <grates_yearmonth> (see grates::as_yearmonth())

• "yearly" -> <grates_year> (see grates::as_year())

Examples

set.seed(1)
linelist <- sim_linelist()
linelist_cens <- censor_linelist(linelist, interval = "daily")

# censor to a 3-day period
linelist_cens <- censor_linelist(linelist, interval = 3)

# no reporting of events on weekends
linelist_cens <- censor_linelist(
  linelist,
  interval = "daily",
  reporting_artefact = "weekend_effects"
)