| Type: | Package | 
| Title: | KONP Tests: Powerful K-Sample Tests for Right-Censored Data | 
| Version: | 1.0.4 | 
| Date: | 2021-12-27 | 
| Author: | Matan Schlesinger [cre, aut], Malka Gorfine [aut] | 
| Maintainer: | Matan Schlesinger <matan.schles@gmail.com> | 
| Description: | The K-sample omnibus non-proportional hazards (KONP) tests are powerful non-parametric tests for comparing K (>=2) hazard functions based on right-censored data (Gorfine, Schlesinger and Hsu, 2020, <doi:10.1177/0962280220907355>). These tests are consistent against any differences between the hazard functions of the groups. The KONP tests are often more powerful than other existing tests, especially under non-proportional hazard functions. | 
| License: | GPL-2 | GPL-3 [expanded from: GPL (≥ 2)] | 
| Imports: | survival,Rcpp (≥ 0.12.16) | 
| LinkingTo: | Rcpp | 
| RoxygenNote: | 7.0.0 | 
| Encoding: | UTF-8 | 
| Suggests: | testthat | 
| NeedsCompilation: | yes | 
| Packaged: | 2022-01-03 16:28:18 UTC; matan.schlesinger | 
| Repository: | CRAN | 
| Date/Publication: | 2022-01-03 17:10:12 UTC | 
KONP Tests for Testing the Equality of K Distributions for Right-Censored Data
Description
An implementation of the K-sample omnibus non-proportional hazrds (KONP) tests.
The KONP tests are powerful non-parametric tests for comparing K (>=2) hazard functions based on right-censored data. These tests are consistent against any differences between the hazard functions of the groups.
The KONP tests are often more powerful than other existing tests, especially under non-proportional hazard functions.
Details
The package contains one function:
konp_test: non-parametric tests for equality of K distributions using right-censored data.
Author(s)
Author and Maintainer: Matan Schlesinger matan.schles@gmail.com
Author: Malka Gorfine gorfinem@tauex.tau.ac.il
References
Gorfine, M., Schlesinger, M., & Hsu, L. (2020). K-sample omnibus non-proportional hazards tests based on right-censored data. Statistical Methods in Medical Research, 29(10), 2830–2850.
doi: 10.1177/0962280220907355
Examples
  
# gastric cancer data  
data(gastric)
konp_test(gastric$time, gastric$status, gastric$group, n_perm=10^3)
  
Urothelial carcinoma.
Description
Survival data from a trial comparing chemotherapy versus atezolizumab in the treatment of Urothelial carcinoma.
Usage
data(carcinoma)
Format
A data frame with 625 observations (316 in the atezolizumab group and 309 chemotherapy group) with the following 3 columns:
- time
- the observed follow-up times in days. 
- status
- the event indicators, 0=right censored, 1= event. 
- group
- the group labels, 1 = atezolizumab, 2 = chemotherapy. 
References
Powles T, Dura?n I, van der Heijden MS, et al. Atezolizumab versus chemotherapy in patients with platinum-treated locally advanced or metastatic urothelial carcinoma (IMvigor211): a multicentre, open-label, phase 3 randomised controlled trial. Lancet 2018; 391: 748-757.
Gastric Cancer Data.
Description
Survival data from a trial comparing chemotherapy versus combined chemotherapy plus radiotherapy in the treatment of gastric cancer.
Usage
data(gastric)
Format
A data frame with 90 observations (45 in each treatment group) with the following 3 columns:
- time
- the observed follow-up times in days. 
- status
- the event indicators, 0=right censored, 1= event. 
- group
- the group labels, 1 = chemotherapy, 2 = chemotherapy plus radiotherapy. 
Source
Stablein, D. M. and Koutrouvelis, I. A. (1985) A two-sample test sensitive to crossing hazards in uncensored and singly censored data. Biometrics 41, 643–652. (Page 649).
References
Gastrointestinal Tumor Study Group: Schein, P. D., Stablein, D. M., Bruckner, H. W., Douglass, H. O., Mayer, R., et al. (1982). A comparison of combination chemotherapy and combined modality therapy for locally advanced gastricarcinoma. Cancer 49, 1771-1777.
KONP tests are K-sample Omnibus Non-Proportional hazards tests for right-censored data.
Description
KONP tests are K-sample Omnibus Non-Proportional hazards tests for right-censored data.
Usage
konp_test(time, status, group, n_perm, n_impu = 1)
Arguments
| time | A vector of the observed follow-up times. | 
| status | A vector of event indicators, 0=right censored, 1= event at  | 
| group | A vector denoting the group labels, must contain at least two different values. | 
| n_perm | The number of permutations. | 
| n_impu | The number of imputations, for each imputation n_perm permutations will be executed. | 
Details
The KONP tests are powerful non-parametric tests for comparing K (>=2) hazard functions based on right-censored data.
These tests are consistent against any differences between the hazard functions of the groups.
The KONP tests are often more powerful than other existing tests, especially under non-proportional hazard functions.
Value
Three test statistics and their respective p-values are returned: 
 
pv_chisq - returns the p-value based on the KONP test chi-square statistic. 
 
pv_lr - returns the p-value based on the KONP test likelihood ratio statistic. 
 
pv_cauchy - returns the p-value based on the KONP-based Cauchy-combination test statistic. 
 
chisq_test_stat - returns the KONP test chi-squared test statistic. 
 
lr_test_stat - returns the KONP test likelihood-ratio test statistic. 
cauchy_test_stat - returns the KONP-based Cauchy-combination test statistic.
Examples
# gastric cancer data
data(gastric)
konp_test(gastric$time, gastric$status, gastric$group, n_perm=10^3)