Marginal Partial Likelihood Approach in the Cox Model with Non-ignorable Missing Covariates

2009 ◽  
Author(s):  
Liu Huanbin ◽  
Sun Liuquan
Keyword(s):  
Cox Model ◽  
Partial Likelihood ◽  
Missing Covariates ◽  
Likelihood Approach

scholarly journals ESTIMASI PARAMETER PADA MODEL COX MULTIVARIAT DENGAN METODE MAXIMUM PARTIAL LIKELIHOOD ESTIMATION

2012 ◽  
Vol 4 (1) ◽  
pp. 185
Author(s):  
Irfan Wahyudi ◽  
Purhadi Purhadi ◽  
Sutikno Sutikno ◽  
Irhamah Irhamah
Keyword(s):  
Parameter Estimation ◽  
Likelihood Function ◽  
Cox Model ◽  
Hessian Matrix ◽  
Likelihood Estimation ◽  
Partial Likelihood ◽  
Estimation Methods ◽  
Hazard Functions ◽  
Score Vector ◽  
Parameter Estimation Methods

Multivariate Cox proportional hazard models have ratio property, that is the ratio of  hazard functions for two individuals with covariate vectors  z1 and  z2 are constant (time independent). In this study we talk about estimation of prameters on multivariate Cox model by using Maximum Partial Likelihood Estimation (MPLE) method. To determine the appropriate estimators  that maximize the ln-partial likelihood function, after a score vector and a Hessian matrix are found, numerical iteration methods are applied. In this case, we use a Newton Raphson method. This numerical method is used since the solutions of the equation system of the score vector after setting it equal to zero vector are not closed form. Considering the studies about multivariate Cox model are limited, including the parameter estimation methods, but the methods are urgently needed by some fields of study related such as economics, engineering and medical sciences. For this reasons, the goal of this study is designed to develop parameter estimation methods from univariate to multivariate cases.

scholarly journals Event history analysis of dynamic networks

Biometrika ◽  
2020 ◽  
Author(s):  
T Sit ◽  
Z Ying ◽  
Y Yu
Keyword(s):  
Event History Analysis ◽  
Dynamic Networks ◽  
Partial Likelihood ◽  
Event History ◽  
Dependence Structure ◽  
Counting Processes ◽  
Asymptotic Results ◽  
History Analysis ◽  
History Of ◽  
Likelihood Approach

Summary Statistical analysis on networks has received growing attention due to demand from various emerging applications. In dynamic networks, one of the key interests is to model the event history of time-stamped interactions among nodes. We model dynamic directed networks via multivariate counting processes. A pseudo partial likelihood approach is exploited to capture the network dependence structure. Asymptotic results are established. Numerical experiments are performed to demonstrate the effectiveness of our proposal.

Heterogeneous Capture-Recapture Models with Covariates: A Partial Likelihood Approach for Closed Populations

Biometrics ◽  
2011 ◽  
Vol 67 (4) ◽  
pp. 1659-1665 ◽  
Author(s):  
Jakub Stoklosa ◽  
Wen-Han Hwang ◽  
Sheng-Hai Wu ◽  
Richard Huggins
Keyword(s):  
Partial Likelihood ◽  
Capture Recapture ◽  
Likelihood Approach ◽  
Closed Populations

Outcome of octogenarian versus (vs) young patients (pts) with metastatic renal cell carcinoma (mRCC), treated with sunitinib (su).

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 538-538
Author(s):  
Igal Kushnir ◽  
Eli Rosenbaum ◽  
Avishay Sella ◽  
David Sarid ◽  
Maya Gottfried ◽  
...  
Keyword(s):  
Side Effects ◽  
Dose Reduction ◽  
Multivariate Analyses ◽  
Cox Model ◽  
Young Patients ◽  
Treatment Interruption ◽  
Partial Likelihood ◽  
Reduction Treatment ◽  
Baseline Characteristics ◽  
Group 1

538 Background: Su is a standard treatment (tx) for mRCC. Octogenarian pts (aged ≥ 80) are often considered to be unfit for su tx, and recommendations for their tx is limited by the paucity of clinical trials data in this population. We aimed to study baseline characteristics and outcome of octogenarian vs young (aged ≤45) pts with mRCC treated with su. Methods: We performed an international multicenter retrospective study of pts with mRCC, who were treated with su in 8 centers across 2 different countries. We compared baseline characteristics and outcome of octogenarian versus young pts. The effect of very old age on response rate (RR), progression free survival (PFS) and overall survival (OS), was tested with adjustment of other known confounding risk factors using a chi-square test and partial likelihood test from cox model. Furthermore, univariate and multivariate analyses of association between clinicopathologic factors and age, and outcome were performed using the entire pt cohort. Results: Between 2004-2013, 36 octogenarian (group 1; median age 83) and 37 young (group 2; median age 42) mRCC were treated with su. The groups were balanced regarding the following baseline clinicopathologic characteristics: gender, HENG risk, past nephrectomy, mRCC histology, ≥ 2 metastatic sites, lung/liver/bone metastasis, prior targeted tx, smoking status, use of angiotensin system inhibitors (ASIs), pre-tx neutrophil to lymphocyte ratio (NLR) >3, and sunitinib induced hypertension (HTN). In group 1 vs 2, 53% vs 27% (p=0.006) had dose reduction/treatment interruption d/t side effects. Clinical benefit (partial response + stable disease) in group 1 vs 2 was 76% vs 84%, while 24% vs 16% had disease progression within the first 3 months of tx (p=0.09). Median PFS was 11 vs 8 months (p=0.1). Median OS was 22 vs 20 months (p=0.7). In multivariate analyses of the entire pt cohort (n=73), age was not significantly associated with PFS or OS. Conclusions: Su is active in octogenarian mRCC pts. Vs young pts, a significantly higher proportion of octogenarian pts had dose reduction/treatment interruption d/t side effects.

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