scholarly journals Joint Modeling of  Longitudinal Ordinal Data on  Quality of Life and Survival

2021 ◽  
Author(s):  
◽  
Kemmawadee Preedalikit
Keyword(s):  
Quality Of Life ◽  
Survival Data ◽  
Latent Variable ◽  
Ordinal Data ◽  
Likelihood Function ◽  
Joint Model ◽  
Hiv Progression ◽  
Bayesian Joint Model ◽  
Lower Hazard

<p>Joint models for longitudinal and survival data have been widely discussed in the literature. This thesis proposes a joint model using a stereotype model for the longitudinal ordinal responses and a Cox proportional hazards model for survival time. Our current joint model has a new feature since no literature has examined the joint model under the stereotype model. The stereotype model can improve the fit by adding extra score parameters, but it still has the advantage of requiring only a single parameter to describe the effect of a predictor on the item response levels. We give an example to model longitudinal ordinal data and survival data for patients being followed up after treatments. The main focus is on modeling both the quality of life data and the survival data simultaneously with a goal of understanding the association between the two processes over time. These two models are linked through a latent variable that characterizes the quality of life of an individual and is assumed to underlie the hazard rate. In other words, the latent variable serves as a shared variable in the joint model. We present the joint model in two different aspects: one based on a Bayesian approach and the other one a semiparametric approach using the EM algorithm. For the Bayesian approach, the latent variable is treated as a continuous variable and is assumed to have a multivariate normal distribution. The partial survival likelihood function is used in the survival component of the Bayesian joint model, while the full likelihood function is considered in the semiparametric joint model. In the latter approach the baseline hazard is assumed to be a step function and has no parametric form. The latent variable in the semiparametric joint model is then treated as a discrete variable. We illustrate our methodologies by analyzing data from the Staccato study, a randomized trial to compare two treatment methods, for Human Immunodeficiency Virus (HIV) infection of Thai patients on Highly Active Antiretroviral Therapy (HAART), in which the quality of life was assessed with a HIV Medical Outcome Study (MOS-HIV) questionnaire. Furthermore, we extend the study further to the case of multiple failure types in the survival component. Thus, the extension of the joint model consists of the stereotype model and the competing risks model. The Bayesian method is employed to estimate all unknown parameters in this extended joint model. The results we obtained are consistent for both the Bayesian joint model and the semiparametric joint model. Both models show that patients who had a better quality of life were associated with a lower hazard of HIV progression. Patients on continuous treatment also had a lower hazard of HIV progression compared with patients on CD4-guided interruption treatment.</p>

scholarly journals Joint Modeling of  Longitudinal Ordinal Data on  Quality of Life and Survival

2021 ◽  
Author(s):  
◽  
Kemmawadee Preedalikit
Keyword(s):  
Quality Of Life ◽  
Survival Data ◽  
Latent Variable ◽  
Ordinal Data ◽  
Likelihood Function ◽  
Joint Model ◽  
Hiv Progression ◽  
Bayesian Joint Model ◽  
Lower Hazard

<p>Joint models for longitudinal and survival data have been widely discussed in the literature. This thesis proposes a joint model using a stereotype model for the longitudinal ordinal responses and a Cox proportional hazards model for survival time. Our current joint model has a new feature since no literature has examined the joint model under the stereotype model. The stereotype model can improve the fit by adding extra score parameters, but it still has the advantage of requiring only a single parameter to describe the effect of a predictor on the item response levels. We give an example to model longitudinal ordinal data and survival data for patients being followed up after treatments. The main focus is on modeling both the quality of life data and the survival data simultaneously with a goal of understanding the association between the two processes over time. These two models are linked through a latent variable that characterizes the quality of life of an individual and is assumed to underlie the hazard rate. In other words, the latent variable serves as a shared variable in the joint model. We present the joint model in two different aspects: one based on a Bayesian approach and the other one a semiparametric approach using the EM algorithm. For the Bayesian approach, the latent variable is treated as a continuous variable and is assumed to have a multivariate normal distribution. The partial survival likelihood function is used in the survival component of the Bayesian joint model, while the full likelihood function is considered in the semiparametric joint model. In the latter approach the baseline hazard is assumed to be a step function and has no parametric form. The latent variable in the semiparametric joint model is then treated as a discrete variable. We illustrate our methodologies by analyzing data from the Staccato study, a randomized trial to compare two treatment methods, for Human Immunodeficiency Virus (HIV) infection of Thai patients on Highly Active Antiretroviral Therapy (HAART), in which the quality of life was assessed with a HIV Medical Outcome Study (MOS-HIV) questionnaire. Furthermore, we extend the study further to the case of multiple failure types in the survival component. Thus, the extension of the joint model consists of the stereotype model and the competing risks model. The Bayesian method is employed to estimate all unknown parameters in this extended joint model. The results we obtained are consistent for both the Bayesian joint model and the semiparametric joint model. Both models show that patients who had a better quality of life were associated with a lower hazard of HIV progression. Patients on continuous treatment also had a lower hazard of HIV progression compared with patients on CD4-guided interruption treatment.</p>

scholarly journals Nutrition and Breast Cancer: A Literature Review on Prevention, Treatment and Recurrence

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1514 ◽  
Author(s):  
Paola De Cicco ◽  
Maria Valeria Catani ◽  
Valeria Gasperi ◽  
Matteo Sibilano ◽  
Maria Quaglietta ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Survival Data ◽  
Saturated Fatty Acids ◽  
Nutritional Intervention ◽  
Dietary Factors ◽  
Current Evidence ◽  
Drug Induced ◽  
Term Survival

Breast cancer (BC) is the second most common cancer worldwide and the most commonly occurring malignancy in women. There is growing evidence that lifestyle factors, including diet, body weight and physical activity, may be associated with higher BC risk. However, the effect of dietary factors on BC recurrence and mortality is not clearly understood. Here, we provide an overview of the current evidence obtained from the PubMed databases in the last decade, assessing dietary patterns, as well as the consumption of specific food-stuffs/food-nutrients, in relation to BC incidence, recurrence and survival. Data from the published literature suggest that a healthy dietary pattern characterized by high intake of unrefined cereals, vegetables, fruit, nuts and olive oil, and a moderate/low consumption of saturated fatty acids and red meat, might improve overall survival after diagnosis of BC. BC patients undergoing chemotherapy and/or radiotherapy experience a variety of symptoms that worsen patient quality of life. Studies investigating nutritional interventions during BC treatment have shown that nutritional counselling and supplementation with some dietary constituents, such as EPA and/or DHA, might be useful in limiting drug-induced side effects, as well as in enhancing therapeutic efficacy. Therefore, nutritional intervention in BC patients may be considered an integral part of the multimodal therapeutic approach. However, further research utilizing dietary interventions in large clinical trials is required to definitively establish effective interventions in these patients, to improve long-term survival and quality of life.

scholarly journals BERPIKIR KRITIS DAN BERPIKIR KREATIF PEKERJA PEREMPUAN DI SURABAYA UNTUK KESEJAHTERAAN KELUARGA MELALUI PENINGKATAN KUALITAS HIDUP KELUARGA

2020 ◽  
Vol 18 (3) ◽  
pp. 287
Author(s):  
Rina Dewi ◽  
Wiratna Wiratna
Keyword(s):  
Quality Of Life ◽  
Critical Thinking ◽  
Women Workers ◽  
Family Life ◽  
Latent Variable ◽  
Creative Thinking ◽  
Equation Modeling ◽  
Family Welfare ◽  
Quality Of Family Life

The purpose of this study is to look at the effect of critical thinking and creative thinking on family welfare through intervening variables of quality of life in women workers in Surabaya. The concept of a research framework is built on understanding existing theories about critical thinking, creative thinking and reconstruction of family welfare through the quality of family life. This study consisted of 305 samples of female workers in Surabaya who had school-age children. Data obtained from questionnaires distributed to respondents. Using Structural Equation Modeling statistical modeling techniques, with Stata 14 Software. Critical thinking and creative thinking are needed for women workers to be able to do time, mind and energy management for office work and household chores so that a better quality of life will ultimately lead to family welfare. From this study the results were obtained the first model Y = 0.51 X1 + 0.47 X2, which means that exogenous variables consisting of critical thinking (X1) and creative thinking have a positive and significant effect on intervening endogenous variables, namely quality of life (Y) The Second Model Z = 0.93 Y which means the quality of life variable (Y) has a positive and significant effect on the dependent variable namely family welfare (Z). All latent variable indicators have a positive and significant effect with z values> 1.96. This research illustrates the importance of critical thinking and creative thinking for women workers in fighting for the quality of family life in order to achieve a prosperous family. This cannot be formed quickly, it takes time to continue to enrich themselves with new knowledge and insights.

scholarly journals A semiparametric joint model for terminal trend of quality of life and survival in palliative care research

2017 ◽  
Vol 36 (29) ◽  
pp. 4692-4704 ◽  
Author(s):  
Zhigang Li ◽  
H.R. Frost ◽  
Tor D. Tosteson ◽  
Lihui Zhao ◽  
Lei Liu ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Palliative Care ◽  
Joint Model ◽  
Care Research

Transoral Laser Excision of Base of Tongue Cancer

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P47-P47
Author(s):  
April A. Camp ◽  
Guy J Petruzzelli ◽  
Christopher Fundakowski
Keyword(s):  
Quality Of Life ◽  
Overall Survival ◽  
Survival Data ◽  
Tertiary Care ◽  
Care Facility ◽  
Base Of Tongue ◽  
Tertiary Care Facility ◽  
Laser Excision ◽  
Disease Specific

Objective Recently, the use of laser in head and neck surgery has increased, consequent to technical advances in laser technology and visualization techniques. The objective of this study was to determine survival and qualitative results in patients who have undergone transoral laser excision of base of tongue (BOT) squamous cell carcinoma (SCCA). Methods A retrospective chart review was performed of patients with previously untreated, biopsy proven SCCA of the BOT treated with transoral laser excision at a tertiary care facility. All patients had follow-up for at least 24 months. Disease specific and overall survival data was determined using Kaplan-Meier approximations. Quality of life (QOL) data was obtained via interview using a well established questionnaire. Results Between 1995 and 2005, 71 patients, ages 38–85, were treated with transoral laser excision for BOT SCCA; 1.4, 12.7, 9.9, and 75% were stage I, II, III, and IV, respectively, at diagnosis. At 24 months, overall survival was 90%, while disease-specific survival was 94%. No correlation was found between survival and gender, overall stage, tumor size, nodal status, or adjuvant therapy. Local-regional recurrence occurred in 10% of patients. QOL data was obtained for 46 patients and yielded acceptable results, with 52% of patients reporting mild or no pain, 98% reporting minimal impairment to normal swallowing, and 70% reporting normal speech. Conclusions Transoral laser excision is an innovative method for excision of BOT SCCA and offers an improved approach in terms of survival and quality of life for treatment of these lesions.

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