Censored data (see entry) is data where at least some values are not know accurately but are known to be bigger than a given value, less than a given value, or between two values.
Left censored data is the first of those: data where at least some values are known to be below a value but not known precisely. This typically happens in routine database data or when looking retrospectively at events. We may know that one client’s first contact with a service was on or before some date when a routine database was created but it may not be possible to find out the precise first date. This is the complement of right censored data.
Details #
This matters because if we ignore the censoring we have introduced a bias into our estimation of general durations of therapies for that study. However, there are statistical methods that handle censoring and will avoid that bias (given some sensible assumptions mostly that the pattern of duration hasn’t actually changed across the period of the study). See survival analysis for probably the biggest class of such methods.
Try also #
Censored data
Frailty analysis
Interval censoring
Right censoring
Survival analysis
Type I censoring
Type II censoring
Chapters #
Not covered in the OMbook.
Online resources #
None forseeable.
Dates #
First created 10.xii.24, links tweaked 15.xii.24.
