Title: | Sample Size Calculation for the Proportional Hazards Mixture Cure Model |
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Description: | An R-package for calculating sample size of a survival trial with or without cure fractions. |
Authors: | Chao Cai, Songfeng Wang, Wenbin Lu, Jiajia Zhang |
Maintainer: | Chao Cai <[email protected]> |
License: | GPL-2 |
Version: | 2.3 |
Built: | 2024-11-29 08:46:01 UTC |
Source: | CRAN |
Estimating sample size for survival trial with or without cure fractions
Package: | NPHMC |
Type: | Package |
Version: | 2.2 |
Date: | 2013-09-23 |
License: | GPL-2 |
LazyLoad: | yes |
Chao Cai, Songfeng Wang, Wenbin Lu, Jiajia Zhang
Maintainer: Chao Cai <[email protected]>
S. Wang, J. Zhang, and W. Lu. Sample size calculation for the proportional hazards cure model. Statistics in medicine, 31:3959-3971, 2012
C. Cai, et al., smcure: An R-Package for estimating semiparametric mixture cure models. Computer Methods and Programs in Biomedicine, 108(3):1255-60, 2012
Example data of nonparametric estimation approach with treatment as only covariate
data(e1684szdata)
data(e1684szdata)
A data frame with 285 observations on the following 3 variables:
Time
observed relapse-free time
Status
censoring indicator (1 = event of interest happens, and 0 = censoring)
X
arm indicator (1 = treatment and 0 = control)
data(e1684szdata)
data(e1684szdata)
The first integrate function
f1(t, survdist, k, lambda0)
f1(t, survdist, k, lambda0)
t |
time variable |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
The second integrate function
f2(t, accrualtime, followuptime, accrualdist, survdist, k, lambda0)
f2(t, accrualtime, followuptime, accrualdist, survdist, k, lambda0)
t |
time variable |
accrualtime |
length of accrual period. |
followuptime |
length of follow-up time. |
accrualdist |
accrual pattern. It can be " |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
The third integrate function
f3(t, beta0, gamma0, pi0, survdist, k, lambda0)
f3(t, beta0, gamma0, pi0, survdist, k, lambda0)
t |
time variable |
beta0 |
log hazard ratio of uncured patients |
gamma0 |
log odds ratio of cure rates between two arms |
pi0 |
cure rate for the control arm, which is between 0 and 1. |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
The fourth integrate function
f4(t, accrualtime, followuptime, accrualdist, beta0, gamma0, pi0, survdist, k, lambda0)
f4(t, accrualtime, followuptime, accrualdist, beta0, gamma0, pi0, survdist, k, lambda0)
t |
time variable |
accrualtime |
length of accrual period. |
followuptime |
length of follow-up time. |
accrualdist |
accrual pattern. It can be " |
beta0 |
log hazard ratio of uncured patients |
gamma0 |
log odds ratio of cure rates between the two arms |
pi0 |
cure rate for the control arm, which is between 0 and 1. |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
Cumulative Hazard Function for Exponential and Weibull Distributions
H0(t, survdist, k, lambda0)
H0(t, survdist, k, lambda0)
t |
time variable |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
M integrate function
m(t, beta0, gamma0, pi0, survdist, k, lambda0)
m(t, beta0, gamma0, pi0, survdist, k, lambda0)
t |
time variable |
beta0 |
log hazard ratio of uncured patients |
gamma0 |
log odds ratio of cure rates between two arms |
pi0 |
cure rate for the control arm, which is between 0 and 1. |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
the scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
Title
NPHMC( n = NULL, power = 0.8, alpha = 0.05, accrualtime = NULL, followuptime = NULL, p = 0.5, accrualdist = c("uniform", "increasing", "decreasing"), hazardratio = NULL, oddsratio = NULL, pi0 = NULL, survdist = c("exp", "weib"), k = 1, lambda0 = NULL, data = NULL )
NPHMC( n = NULL, power = 0.8, alpha = 0.05, accrualtime = NULL, followuptime = NULL, p = 0.5, accrualdist = c("uniform", "increasing", "decreasing"), hazardratio = NULL, oddsratio = NULL, pi0 = NULL, survdist = c("exp", "weib"), k = 1, lambda0 = NULL, data = NULL )
n |
sample size needed for power calculation |
power |
powered needed for sample size calculation |
alpha |
level of significance of statistical test (default is 0.05) |
accrualtime |
level of accrual period |
followuptime |
length of follow up time |
p |
proportion of subjects in treatment arm (default is 0.5) |
accrualdist |
accrual pattern (uniform, decreasing, increasing) |
hazardratio |
hazard ratio of uncured patients between two arms (must be greater than 0) |
oddsratio |
odds ratio of cured patients between two arms. It must be greater than 0. If it is 0, the model is reduced to standard proportional hazards model. |
pi0 |
cure rate for the control arm (between 0 and 1) |
survdist |
distribution of uncured patients ( |
k |
shape parameter if survdist = 'weib' (By default, it is 1 referrring to exponential distribution) |
lambda0 |
scale parameter of exponential or Weibull distribution for survival times of uncured patients in the control arm. |
data |
observed or historical data if available |
a NPHMC object
NPHMC(power=0.90,alpha=0.05,accrualtime=3,followuptime=4,p=0.5,accrualdist="uniform", hazardratio=2/2.5,oddsratio=2.25,pi0=0.1,survdist="exp",k=1,lambda0=0.5) data(e1684szdata) NPHMC(power=0.80,alpha=0.05,accrualtime=4,followuptime=3,p=0.5,accrualdist="uniform", data=e1684szdata) n=seq(100, 500, by=50) NPHMC(n=n, alpha=0.05,accrualtime=3,followuptime=4,p=0.5, accrualdist="uniform", hazardratio=2/2.5,oddsratio=2.25,pi0=0.1,survdist="exp", k=1,lambda0=0.5) n=seq(100, 500, by=50) NPHMC(n=n,alpha=0.05,accrualtime=4,followuptime=3,p=0.5, accrualdist="uniform",data=e1684szdata)
NPHMC(power=0.90,alpha=0.05,accrualtime=3,followuptime=4,p=0.5,accrualdist="uniform", hazardratio=2/2.5,oddsratio=2.25,pi0=0.1,survdist="exp",k=1,lambda0=0.5) data(e1684szdata) NPHMC(power=0.80,alpha=0.05,accrualtime=4,followuptime=3,p=0.5,accrualdist="uniform", data=e1684szdata) n=seq(100, 500, by=50) NPHMC(n=n, alpha=0.05,accrualtime=3,followuptime=4,p=0.5, accrualdist="uniform", hazardratio=2/2.5,oddsratio=2.25,pi0=0.1,survdist="exp", k=1,lambda0=0.5) n=seq(100, 500, by=50) NPHMC(n=n,alpha=0.05,accrualtime=4,followuptime=3,p=0.5, accrualdist="uniform",data=e1684szdata)
Baseline survival function for mixture cure model
S0(t, pi0, survdist, k, lambda0)
S0(t, pi0, survdist, k, lambda0)
t |
time variable |
pi0 |
cure rate for the control arm, which is between 0 and 1. |
survdist |
survival distribution of uncured patients. It can be " |
k |
if |
lambda0 |
scale parameter of exponential distribution or Weibull distribution for survival times of uncured patients in the control arm. The density function of Weibull distribution with shape parameter
for
|
Survival distribution of censoring times
Sc(t, accrualtime, followuptime, accrualdist)
Sc(t, accrualtime, followuptime, accrualdist)
t |
time variable |
accrualtime |
length of accrual period. |
followuptime |
length of follow-up time. |
accrualdist |
accrual pattern. It can be " |