[R] Survival Analysis Daily Time-Varying Covariate....
Terry Therneau
therneau at mayo.edu
Fri Sep 17 15:39:41 CEST 2010
Help!
I am unsure if I can analyze data from the following experiment.
Fish were placed in a tank at (t=0)
Measurements of Carbon Dioxide were taken each day for 120 days
(t=0,...120)
A few fish were then randomly pulled out of the tank at different days,
killed and examined for the presence of a disease
T= time of examination in days from start (i.e. 85th day), E = 0/1 for
nonevent/event
....
---------------------------
You need to decide on a mechanistic model. On the day a fish is
sacrificed, does their risk of disease depend on
today's CO2 level
the average CO2 since the start of the experiment
cumulative CO2 dose
days over a threshold
etc
You can examine each of these one by one or in combinations. It would
be very difficult, however, to ask your program to "find the pattern".
Terry Therneau
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