The SANAD (Standard and New Anti-epileptic Drugs) study (Marson et al., 2007) is a randomized control trial of standard and new anti-epileptic drugs, comparing effects on longer term clinical outcomes. The data consists of longitudinal measurements of calibrated dose for the groups randomized to a standard drug (CBZ) and a new drug (LTG). The objective of the analysis is to investigate the effect of drug titration on the relative effects of LTG and CBZ on treatment failure (withdrawal of the randomized drug). There are several baseline covariates available, and also data on the time to withdrawal from randomized drug.
data(epileptic)This is a data frame in the unbalanced format, that is, with one row per observation. The data consists of columns for patient identifier, time of measurement, calibrated dose, baseline covariates, and survival data. The column names are identified as follows:
idinteger: patient identifier.
dosenumeric: calibrated dose.
timeinteger: timing of clinic visit at which dose recorded (days).
with.timeinteger: time of drug withdrawal/maximum follow up time (days).
with.statuscensoring indicator (1 = withdrawal of
randomized drug and 0 = not withdrawn from randomized drug/lost to
follow up).
with.status2censoring indicator (1 = withdrawal of
randomized drug due to inadequate seizure control, (2 = withdrawal
of randomized drug due to unacceptable adverse effects, and 0 = not
withdrawn from randomized drug/lost to follow up).
with.status.uae1 = withdrawal due to unacceptable
adverse effects, 0 = otherwise.
with.status.isc1 = withdrawal due to inadequate
seizure control, 0 = otherwise.
treatfactor: randomized treatment (CBZ or LTG).
agenumeric: age of patient at randomization (years).
genderfactor: gender of patient. F = female, M
= male.
learn.disfactor: learning disability.
Marson AG, Appleton R, Baker GA, et al. A randomised controlled trial examining longer-term outcomes of standard versus new antiepileptic drugs. The SANAD Trial. Health Tech Assess. 2007; 11(37).
Marson AG, Al-Kharusi AM, Alwaidh M, et al. The SANAD study of effectiveness of carbamazepine, gabapentin, lamotrigine, oxcarbazepine, or topiramate for treatment of partial epilepsy: an unblinded randomised controlled trial. Lancet. 2007; 365: 2007-2013.
Williamson PR, Kolamunnage-Dona R, Philipson P, Marson AG. Joint modelling of longitudinal and competing risks data. Stats Med. 2008; 27(30): 6426-6438.
heart.valve, liver,
mental, aids.