In
statistics
Statistics (from German language, German: ''wikt:Statistik#German, Statistik'', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of ...
, median follow-up is the
median
In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...
time between a specified event and the time when data on outcomes are gathered. The concept is used in
cancer survival analyses.
Many
cancer studies aim to assess the time between two events of interest, such as from
treatment to
remission, treatment to
relapse
In internal medicine, relapse or recidivism is a recurrence of a past (typically medical) condition. For example, multiple sclerosis and malaria often exhibit peaks of activity and sometimes very long periods of dormancy, followed by relapse or r ...
, or
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...
to death. This duration is generically called
survival time, even if the end point is not death.
must have sufficiently long follow-up durations to capture enough events to reveal meaningful patterns in the data. A short follow-up duration is appropriate for studying very severe cancers with poor
prognoses, whereas a long follow-up duration is better suited to studying less-severe disease, or participants with good prognoses.
[Clark, M. J. Bradburn, S. B. Love and D. G. Altman (15 July 2003). "Survival Analysis Part I: Basic concepts and first analyses". British Journal of Cancer. .]
Median follow-up time is included in about half the survival analyses published in cancer journals, but of those, only 31% specify the method used to compute it.
[Schemper and Terry L. Smith (1996). "A Note on Quantifying Follow-up in Studies of Failure Time". Elsevier (Department of Medical Computer Sciences, Vienna University, Austria).]
References
Biostatistics
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