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Data from 2204 leukaemia patients who received a bone marrow transplant, with times to platelet recovery and to relapse or death (Collett, 2023, Example 13.4).

Usage

bmt_outcome

Format

A data frame with 2204 rows and 9 variables:

id

Patient identifier.

leukaemia

Disease type: "AML", "ALL" or "CML".

age

Age group: "<=20", "21-40" or ">40".

match

Donor-recipient gender match: 0 = no, 1 = yes.

tcell

T-cell depletion: 0 = no, 1 = yes.

ptime

Time from transplantation to platelet recovery, in days.

pcens

Platelet recovery indicator: 0 = censored, 1 = recovery.

rdtime

Time from transplantation to relapse or death, in days.

rdcens

Relapse-or-death indicator: 0 = censored, 1 = event.

Source

Collett, D. (2023) Modelling Survival Data in Medical Research, 4th ed. Chapman & Hall/CRC, Example 13.4 (Table 13.9). Data from the EBMT Registry, see Putter, Fiocco and Geskus (2007).

Details

The data come from the European Group for Blood and Marrow Transplantation (EBMT) Registry, and are the version used by Putter, Fiocco and Geskus (2007). Following the transplant a patient may either recover platelet function and later relapse or die, or relapse or die before platelet recovery. The data therefore describe a three-state model with transition rates for transplantation to platelet recovery, transplantation to relapse or death, and platelet recovery to relapse or death.

Of the 2204 patients, 1169 experienced platelet recovery and 458 relapsed or died before their platelet count had returned to normal; a further 383 patients relapsed or died after platelet recovery. Note that the ptime of a patient who relapsed before recovering platelets is censored at the time of relapse when the first transition is modelled. To fit the model the data are expanded into one row per possible transition per patient (Example 13.4).

Aliases

The data set is available under the alias d13.4; dX.Y is the alias for the data set used in Example X.Y of Collett (2023). See dataset_by_exercise for the complete index.

Examples

# Collett (2023), Chapter 17 style -----------------------------------
# Example 13.4: the two endpoints of the three-state model
# 1 -> 2: platelet recovery
survival::coxph(
  survival::Surv(ptime, pcens) ~ leukaemia + age + match + tcell,
  data = bmt_outcome
)
#> Call:
#> survival::coxph(formula = survival::Surv(ptime, pcens) ~ leukaemia + 
#>     age + match + tcell, data = bmt_outcome)
#> 
#>                  coef exp(coef) se(coef)      z        p
#> leukaemiaAML  0.04399   1.04497  0.07789  0.565   0.5722
#> leukaemiaCML -0.25403   0.77567  0.08297 -3.062   0.0022
#> age<=20       0.16313   1.17719  0.07905  2.064   0.0390
#> age>40        0.07137   1.07398  0.06776  1.053   0.2922
#> match         0.04745   1.04859  0.06661  0.712   0.4762
#> tcell         0.43133   1.53931  0.08040  5.365 8.11e-08
#> 
#> Likelihood ratio test=56.99  on 6 df, p=1.835e-10
#> n= 2204, number of events= 1169 
# 1 -> 3: relapse or death before recovery
survival::coxph(
  survival::Surv(rdtime, rdcens) ~ leukaemia + age + match + tcell,
  data = bmt_outcome
)
#> Call:
#> survival::coxph(formula = survival::Surv(rdtime, rdcens) ~ leukaemia + 
#>     age + match + tcell, data = bmt_outcome)
#> 
#>                  coef exp(coef) se(coef)      z        p
#> leukaemiaAML -0.21088   0.80988  0.09972 -2.115   0.0345
#> leukaemiaCML -0.06129   0.94055  0.09850 -0.622   0.5338
#> age<=20      -0.17669   0.83804  0.10710 -1.650   0.0990
#> age>40        0.37699   1.45789  0.07609  4.955 7.25e-07
#> match         0.03522   1.03585  0.07922  0.445   0.6566
#> tcell         0.18945   1.20858  0.09523  1.989   0.0467
#> 
#> Likelihood ratio test=49.74  on 6 df, p=5.294e-09
#> n= 2204, number of events= 841 

# Modern tools --------------------------------------------------------
# Transition-specific hazards are fitted by stratifying on the transition
if (requireNamespace("mstate", quietly = TRUE)) {
  tmat <- mstate::transMat(
    list(c(2, 3), 3, c()),
    names = c("transplant", "recovery", "relapse")
  )
  tmat
}
#>             to
#> from         transplant recovery relapse
#>   transplant         NA        1       2
#>   recovery           NA       NA       3
#>   relapse            NA       NA      NA