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Sample Parametric Hazard Model Predictions

Source: R/hazard-plot.R
sample_hazard_data.Rd

Simulates parametric survival, hazard, and cumulative-hazard predictions on a fine time grid, matching the structure of the SAS predict dataset produced by tp.hp.dead.sas and its variants after fitting a Weibull model with PROC LIFEREG.

Usage

sample_hazard_data(
  n = 500,
  time_max = 10,
  n_points = 500,
  groups = NULL,
  shape = 1.5,
  scale = 8,
  ci_level = 0.95,
  seed = 42L
)

Arguments

n

Number of patients used to scale confidence-limit width. Default 500.

time_max

Upper end of the time axis (years). Default 10.

n_points

Number of time points in the prediction grid. Default 500.

groups

NULL for a single curve, or a named numeric vector of hazard multipliers, e.g. c("Control" = 1.0, "Treatment" = 0.7). A multiplier < 1 means lower hazard (better survival). Analogous to the group indicator in tp.hp.dead.tkdn.stratified.sas.

shape

Weibull shape parameter. shape > 1 gives increasing hazard (late mortality); shape < 1 gives decreasing hazard (early operative mortality). Default 1.5.

scale

Weibull scale parameter (characteristic time in years, i.e. the time at which S = exp(-1) ≈ 37%). Default 8.0.

ci_level

Confidence level for the CI bands. Default 0.95.

seed

Random seed (unused for deterministic Weibull predictions; kept for API consistency with other sample functions). Default 42.

Value

A data frame with columns time, survival, surv_lower, surv_upper, hazard, haz_lower, haz_upper, cumhaz, and (when groups is not NULL) group.

Details

SAS column mapping:

  • time ← YEARS / iv_dead (prediction grid)

  • survival ← SSURVIV (predicted survival, 0–100 %)

  • surv_lower ← SCLLSURV (lower confidence limit on survival)

  • surv_upper ← SCLUSURV (upper confidence limit on survival)

  • hazard ← predicted hazard rate (%/year)

  • haz_lower ← lower confidence limit on hazard

  • haz_upper ← upper confidence limit on hazard

  • cumhaz ← cumulative hazard (%; corresponds to -log(S)*100)

  • group ← group stratification variable (when groups is not NULL)

See also

hv_hazard(), sample_hazard_empirical(), sample_life_table()

Examples

# Single-group predictions (tp.hp.dead.sas)
dat <- sample_hazard_data(n = 500, time_max = 10)
head(dat)
#>         time survival surv_lower surv_upper    hazard haz_lower haz_upper
#> 1 0.01000000 99.99558   99.93731        100 0.6629126 0.3996474  1.099602
#> 2 0.03002004 99.97702   99.84413        100 1.1485818 0.6924408  1.905203
#> 3 0.05004008 99.95054   99.75561        100 1.4829116 0.8939968  2.459770
#> 4 0.07006012 99.91808   99.66720        100 1.7546549 1.0578216  2.910523
#> 5 0.09008016 99.88059   99.57770        100 1.9896233 1.1994760  3.300275
#> 6 0.11010020 99.83868   99.48662        100 2.1996335 1.3260840  3.648628
#>        cumhaz cumhaz_lower cumhaz_upper
#> 1 0.004419417            0    0.5871202
#> 2 0.022986980            0    1.3519229
#> 3 0.049470012            0    1.9990187
#> 4 0.081954223            0    2.5912321
#> 5 0.119483723            0    3.1493081
#> 6 0.161453396            0    3.6834317

# Two-group predictions (tp.hp.dead.tkdn.stratified.sas)
dat2 <- sample_hazard_data(
  n = 400, time_max = 10,
  groups = c("No Takedown" = 1.0, "Takedown" = 0.65)
)
head(dat2)
#>         time survival surv_lower surv_upper    hazard haz_lower haz_upper
#> 1 0.01000000 99.99558   99.93043        100 0.6629126 0.3764745  1.167285
#> 2 0.03002004 99.97702   99.82844        100 1.1485818 0.6522907  2.022473
#> 3 0.05004008 99.95054   99.73260        100 1.4829116 0.8421599  2.611175
#> 4 0.07006012 99.91808   99.63759        100 1.7546549 0.9964855  3.089672
#> 5 0.09008016 99.88059   99.54194        100 1.9896233 1.1299263  3.503415
#> 6 0.11010020 99.83868   99.44507        100 2.1996335 1.2491932  3.873210
#>        cumhaz cumhaz_lower cumhaz_upper       group
#> 1 0.004419417            0    0.6558987 No Takedown
#> 2 0.022986980            0    1.5087825 No Takedown
#> 3 0.049470012            0    2.2291318 No Takedown
#> 4 0.081954223            0    2.8874122 No Takedown
#> 5 0.119483723            0    3.5069304 No Takedown
#> 6 0.161453396            0    4.0991449 No Takedown