survm_samplesize {survmixer} | R Documentation |
The function 'survm_samplesize' calculates the sample size according to the distributional parameters of the responders and non-responders.
survm_samplesize(
ascale0_r,
ascale0_nr,
ascale1_r,
ascale1_nr,
delta_p,
p0,
m0_r,
m0_nr,
diffm_r,
diffm_nr,
S0_r,
S0_nr,
diffS_r,
diffS_nr,
Delta_r,
Delta_nr,
ascale_cens,
tau,
bshape0 = 1,
bshape1 = 1,
all_ratio = 0.5,
alpha = 0.025,
beta = 0.2,
set_param = 0
)
ascale0_r |
scale parameter for the Weibull distribution in the control group for responders |
ascale0_nr |
scale parameter for the Weibull distribution in the control group for non-responders |
ascale1_r |
scale parameter for the Weibull distribution in the intervention group for responders |
ascale1_nr |
scale parameter for the Weibull distribution in the intervention group for non-responders |
delta_p |
effect size for the response rate |
p0 |
event rate for the response |
m0_r |
survival mean for responders in the control group |
m0_nr |
survival mean for non-responders in the control group |
diffm_r |
difference in survival means between groups for responders |
diffm_nr |
difference in survival means between groups for responders |
S0_r |
tau-year survival rates for responders in the control group |
S0_nr |
tau-year survival rates for non-responders in the control group |
diffS_r |
difference in tau-year survival rates for responders |
diffS_nr |
difference in tau-year survival rates for non-responders |
Delta_r |
restricted mean survival times (RMST) difference between intervention and control groups for responders |
Delta_nr |
RMST difference between intervention and control groups for non-responders |
ascale_cens |
distributional parameter for the exponential distribution for the censoring |
tau |
follow-up |
bshape0 |
shape parameter for the Weibull distribution in the control group |
bshape1 |
shape parameter for the Weibull distribution in the intervention group |
all_ratio |
allocation ratio. The ratio of numbers of participants allocated in the control group. By default is assumed 1:1 (i.e., all_ratio=0.5) |
alpha |
type I error |
beta |
type II error |
set_param |
Set of parameters to be used for the responders/non-responders survival functions If the set of parameters is =1, then the sample size is computed using the survival means (m0_r,m0_nr,diffm _r,diffm_nr); if set_param=2, it is computed using the tau-year survival rates (S0_r,S0_nr,diffS_r,diffS_nr); if set_param=2, it is computed using the RMSTs and survival rates (Delta_r,Delta_nr,S0_r,S0_nr). If set_param=0, the computation is based on the distributional parameters (ascale0_r, ascale0_nr, ascale1_r, ascale1_nr). |
This function returns the total sample size needed and the expected effect size for overall survival (RMST difference between groups).
Marta Bofill Roig.
Design of phase III trials with long-term survival outcomes based on short-term binary results. Marta Bofill Roig, Yu Shen, Guadalupe Gomez Melis. arXiv:2008.12887