definemissingstatus: Utility function to generate missing status variables in longitudinal data with dropout and/or intermittent missingness.
Description
Utility function to generate missing status variables in longitudinal data with dropout and/or intermittent missingness.
Usage
definemissingstatus(data, id, time, y)
Arguments
data
the name of the panel dataset in the long format with each row denoting a subject-visit observation
for ALL the planned visits, regardless of being missed or not. When a subject is lost to follow up, the data set
must include the observation at the first time of being lost to follow up.
id
the name of the level-2 clustering variable.
time
the name of the variable denoting the time of the visit. Can set time=NULL if data is already sorted by id and time within
id.
y
the name of the outcome variable of the interest that is subject to missingness.
Value
a dataset with the following three new variables added: