This dataset is a reduced version of the dataset colon from the package survival (Therneau, T.M. et al., 2022). Each observation is a transition from recurrence of colon cancer to death or censoring. The time scales are time from randomization to recurrence, time from randomization to death or censoring and time from recurrence of the cancer to death or censoring. Only observations about individuals with a recurrence of the cancer are selected. Additionally, 7 individuals with exit times from the risk set equal to entry times in the recurrence state (0 exposure time) were dropped from the sample. In the original dataset, all times of recurrence are known precisely, so that after recurrence all individuals are followed right from entry in the state, without left truncation. To be able to illustrate how to include left truncated times in the model, artificial left truncated entry in the 'recurrence' state are introduced for 40 individuals.
Usage
data(reccolon2ts)Format
reccolon2ts A data.table with 461 rows and 25 columns:
- id
patient's id
- study
1 for all patients
- rx
Treatment - Obs(ervation), Lev(amisole), Lev(amisole)+5-FU
- sex
1=male, 0=female
- age
Age at transplant in years
- obstruct
obstruction of colon by tumor: 1=yes
- perfor
perforation of colon: 1=yes
- adhere
adherence to nearby organs: 1=yes
- nodes
number of lymph nodes with detectable cancer
- status
censoring status: 0=censoring, 1=event
- differ
differentiation of tumour: 1=well, 2=moderate, 3=poor
- extent
extent of local spread: 1=submucosa, 2=muscle, 3=serosa, 4=contigous structures
- surg
time from surgery to registration: 0=short, 1=long
- node4
more than 4 positive lymph nodes
- etype
2 for all patients (2=death)
- timedc
time in days from randomization to death or censoring
- timer
time in days from randomization to recurrence
- timesr
time in days from recurrence to death or censoring
- entrys
artificial entry time on the time since recurrence scale. For most of the individual this is 0 (no left truncation). For 40 individuals a random number between 1 and the exit time on the time since recurrence scale (timesr) is simulated.
- entryt
time in days from randomization to observation in the recurrence state. If the individual is observed from entry in the recurrence state this is equal to the time at recurrence. If the entry in the recurrence state is not observed from the beginning, left truncation is observed. This is not present in the original data, but has been here introduced artificially for 40 individuals. This is done by first increasing the time at recurrence by a random number between 1 and the exit time on the time since recurrence scale. Then, the time at recurrence is added to the artificial entry time.
- timedc_y
time in years from randomization to death or censoring
- timer_y
time in years from randomization to recurrence
- entrys_y
left truncated entry in the recurrence state measured in years since recurrence
- entryt_y
left truncated entry in the recurrence state measured in years since randomization
- timesr_y
time in years from recurrence to death or censoring
Source
Therneau, T. (2023). A Package for Survival Analysis in R. R package version 3.5-3, https://CRAN.R-project.org/package=survival
References
Moertel, C.G, et al. (1995). Fluorouracil plus Levamisole as Effective Adjuvant Theraphy after Resection of Stage III Colon Carcinoma: A Final Report. Annals of Internal Medicine, 122:321-326
Moerel, C.G., et al. (1990). Levamisole and Fluorouracil for Adjvant Theraphy of Resected Colon Carcinoma. The New England Journal of Medicine, 322:352-8
Examples
data(reccolon2ts)