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Ponnuraja, C.
- Correlated Frailty Model: an Advantageous Approach for Covariate Analysis of Tuberculosis Data
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PDF Views:91
Authors
Affiliations
1 Tuberculosis Research Centre (ICMR), Chennai-600 031, IN
1 Tuberculosis Research Centre (ICMR), Chennai-600 031, IN
Source
Indian Journal of Science and Technology, Vol 3, No 2 (2010), Pagination: 151-155Abstract
The demonstration of varying treatment effects among different subjects of patients is an important part of the analysis of clinical trials. But issues of censoring, truncation and inclusion criteria complicate the analysis of clinical trial data. Recent advances in proportional hazard methodologies provide regression diagnostics, improved point and interval estimates of the parameters of survival functions, handling of time dependent covariates in the analysis. This paper discusses the interactions between treatment and patient in the presence of censoring and to account heterogeneity using frailty model. The application of the frailty model with respect to pulmonary tuberculosis data are presented and discussed.Keywords
Tuberculosis, Cox Proportional Hazard Model, Time-dependent Covariates, Gamma Shared Frailty ModelFull Text
References
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- Tuberculosis Research Centre, ICMR, Chennai, India (2004) Split-drug regimens for the treatment of patients with sputum smear-positive pulmonary tuberculosis- a unique approach. Trop. Med. Int. Health. 9, 551-58.
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- Survival Models for Exploring Tuberculosis Clinical Trial Data - An Empirical Comparison
Abstract Views :442 |
PDF Views:112
Authors
Affiliations
1 Tuberculosis Research Centre (ICMR), Chennai-600 031, IN
1 Tuberculosis Research Centre (ICMR), Chennai-600 031, IN
Source
Indian Journal of Science and Technology, Vol 3, No 7 (2010), Pagination: 755-758Abstract
The proportional hazard (PH) model and its extension are used comprehensively to assess the effect of an intervention in the presence of covariates. The assumptions of PH model may not hold where the effect of the intervention is to accelerate the onset of an event. The accelerated failure time (AFT) model is the alternative when the PH assumption does not hold. The aim of this paper is to formulate a model that yields biological plausible and interpretable estimates of the effect of important covariates on survival time. The data consists of 1236 tuberculosis patients admitted in randomized controlled clinical trial. A total of six covariates are considered for modeling. The AFT model gives better prediction than the Cox PH model.Keywords
Accelerated Failure Time Model, Proportional Hazards Model, Time Dependent Covariate, TuberculosisFull Text
References
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- TRC (Tuberculosis Research Centre, ICMR, Chennai, India) (2004) Split-drug regimens for the treatment of patients with sputum smear-positive pulmonary tuberculosis-a unique approach. Tropical Med. Int. Health. 9, 551-558.