A unified approach for synthesizing population‐level covariate effect information in semiparametric estimation with survival data

2020 ◽  
Vol 39 (10) ◽  
pp. 1573-1590
Author(s):  
Chiung‐Yu Huang ◽  
Jing Qin
Keyword(s):  
Survival Data ◽  
Semiparametric Estimation ◽  
Population Level ◽  
Covariate Effect ◽  
Unified Approach

scholarly journals EPID-36. ANTIDEPRESSANT DRUG USE IN GLIOBLASTOMA PATIENTS: AN EPIDEMIOLOGICAL VIEW

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii86-ii86
Author(s):  
Dorothee Gramatzki ◽  
James Rogers ◽  
Marian Neidert ◽  
Caroline Hertler ◽  
Emilie Le Rhun ◽  
...  
Keyword(s):  
Overall Survival ◽  
Multivariate Analysis ◽  
Drug Use ◽  
Survival Data ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Methylation Status ◽  
Antidepressant Drug ◽  
Antidepressant Drugs ◽  
Population Level ◽  
Disease Course

Abstract PURPOSE Antidepressant drugs have shown anti-tumor activity in preclinical glioblastoma studies. Antidepressant drug use, as well as its association with survival, in glioblastoma patients has not been well characterized on a population level. METHODS Patient characteristics, including the frequency of antidepressant drug use, were assessed in a glioblastoma cohort diagnosed in a 10-year time-frame between 2005 and 2014 in the Canton of Zurich, Switzerland. Cox proportional hazards regression models were applied for multivariate analysis. Kaplan-Meier survival curves were used to estimate overall survival data and the log-rank test was performed for comparisons. RESULTS Four hundred four patients with isocitrate dehydrogenase (IDH) wildtype glioblastoma were included in this study. Sixty-five patients (16.1%) took antidepressant drugs at some point during the disease course. Patients were most commonly prescribed selective serotonin reuptake inhibitors at any time (N=46, 70.8%). Nineteen patients (29.2%) were on antidepressant drugs at the time of their tumor diagnosis. No differences were observed in overall survival between those patients who had taken antidepressants at some point in their disease course and those who had not (p=0.356). These data were confirmed in a multivariate analysis including age, Karnofsky performance status, gender, extent of resection, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status, and first-line treatment as cofounders (p=0.315). Also, there was no association of use of drugs modulating voltage-dependent potassium channels (citalopram; escitalopram) with survival (p=0.639). CONCLUSIONS This signal-seeking study does not support the hypothesis that antidepressants have antitumor efficacy in glioblastoma on a population level.

scholarly journals Semiparametric Estimation of Task-Based Dynamic Functional Connectivity on the Population Level

2019 ◽  
Vol 13 ◽  
Author(s):  
Maria A. Kudela ◽  
Mario Dzemidzic ◽  
Brandon G. Oberlin ◽  
Zikai Lin ◽  
Joaquín Goñi ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Semiparametric Estimation ◽  
Population Level ◽  
Dynamic Functional Connectivity

scholarly journals Recording of fluid, beverage and water intakes at the population level in Europe

2016 ◽  
Vol 116 (4) ◽  
pp. 677-682 ◽  
Author(s):  
Joan Gandy ◽  
Laurent Le Bellego ◽  
Jürgen König ◽  
Ana Piekarz ◽  
Gabriel Tavoularis ◽  
...  
Keyword(s):  
Economic Status ◽  
Population Level ◽  
Activity Level ◽  
Total Water ◽  
Unified Approach ◽  
Large Variability ◽  
Socio Economic Status ◽  
Dietary Reference Values ◽  
Scientific Opinion ◽  
Food Diaries

AbstractThe European Food Safety Authority’s 2010 scientific opinion on dietary reference values for total water intakes was partly based on observed intakes in population groups. Large variability was observed, and it is unlikely that these differences can be explained by differences in climate, activity level and/or culture. This suggests that there are uncertainties in the methodologies used to assess water intake from food and fluids, including all types of beverages. To determine current methods for recording and reporting total water, beverages and fluid intakes, twenty-one European countries were surveyed using an electronic questionnaire. In total, twelve countries responded and ten completed surveys were summarised. Countries reported that their survey was representative of the population in terms of age and socio-economic status. However, a variety of methods were used – that is, repeated 24-h recalls, estimated food diaries and FFQ. None of the methods were validated to assess water and fluid intakes. The methods used to record liquid foods – for example, soup and diluted drinks – were inconsistent. Clarity and consistency on definitions of categories of beverages to facilitate comparisons between countries are needed. Recommendations for a unified approach to surveying and quantifying intake of water from fluids and foods are proposed.

scholarly journals Population-Level Trends in Early Mortality and Overall Survival of Patients with Multiple Myeloma. Are We Facing Stagnation?

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4760-4760 ◽  
Author(s):  
Luciano J. Costa ◽  
Susan Bal ◽  
Saurabh Chhabra
Keyword(s):  
Multiple Myeloma ◽  
Survival Data ◽  
Research Funding ◽  
Unmet Need ◽  
Malignant Neoplasm ◽  
Relative Survival ◽  
Population Level ◽  
Early Mortality ◽  
Significant Difference ◽  
Race Ethnicity

Background: Therapeutic advances in multiple myeloma (MM) in the last two decades resulted in population-level reduction in early mortality (EM) and improvements in overall and relative survival when consecutive cohorts are compared. We utilized updated information from the Surveillance Epidemiology and End Result (SEER-18) program to test whether prior improvement trends have persisted in more recent years. Methods: Patients diagnosed with MM as first malignant neoplasm between the years of 2001 and 2015 were included in the analysis. Survival data are available up to the end of 2016. We analyzed year-by-year EM, herein defined as death from any cause within the first year of diagnosis of MM. Updated 5-year OS was available for patients diagnosed 2001-2011 and analyzed year-by-year. We also analyzed outcomes using age brackets (<65, 65-74 and 75+ years) and race/ethnicity subgroups [non-Hispanic White (NHW), non-Hispanic Black (NHB) and Hispanic]. Results: There were 54,475 patients included in the EM analysis and 37,452 in the 5-year OS analysis. For the EM analysis, 42.7% of patients were <65, 29.0% were 65-74 and 28.4% were 75+. NHW were 62.0%, NHB 19.7%, Hispanic 11.4% , and 54.6% of patients were male. We observe a year-by-year decline in EM between 2001 (31.0%) and 2012 (20.5%), however no significant reduction in EM was noted between 2013 (19.5%) and 2015 (18.5%) (P= 0.24). Such plateau in EM was also noted in each of the age brackets (Figure 1) and race/ethnicity subsets, with no significant difference seen in the last 3 years of data. For patients diagnosed in 2015, EM remained high at 11.6% for patients <65, 17.1% for patients 65-74, 31.5% for patients 75+, 19.5% for NHW, 18.8% for NHB and 16.8% for Hispanics. Five-year OS improved between cohorts of patients diagnosed in 2001 (29.3%) and patients diagnosed in 2008 (43.3%) (P<0.001), but remained stable for patients diagnosed between 2009 (44.4%) and 2011 (44.2%) (P=0.86). Similar pattern was seen for all age (Figure 2) and race/ethnicity subsets. Conclusions: These data indicate possible stagnation in risk of EM and 5-year survival for patients diagnosed with MM in the US beyond the introduction of proteasome inhibitors and immunomodulatory agents. The absolute risk of EM remains unacceptably high for all ages pointing to an unmet need in MM care. Future data will indicate whether the introduction of monoclonal antibodies and other new classes of drugs will have sufficient impact to change population-level outcomes in MM. Disclosures Costa: Celgene: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding; Fujimoto Pharmaceutical Corporation Japan: Other: Advisor; Janssen: Research Funding, Speakers Bureau; Abbvie: Consultancy; Karyopharm: Consultancy; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau.

scholarly journals Flexible Bayesian excess hazard models using low-rank thin plate splines

2019 ◽  
Vol 29 (6) ◽  
pp. 1700-1714
Author(s):  
Manuela Quaresma ◽  
James Carpenter ◽  
Bernard Rachet
Keyword(s):  
Thin Plate ◽  
Survival Data ◽  
Cancer Survival ◽  
Likelihood Function ◽  
Population Level ◽  
Population Based ◽  
Bayesian Regression ◽  
Low Rank ◽  
Hazard Models ◽  
Thin Plate Splines

Excess hazard models became the preferred modelling tool in population-based cancer survival research. In this setting, the model is commonly formulated as the additive decomposition of the overall hazard into two components: the excess hazard due to the cancer of interest and the population hazard due to all other causes of death. We introduce a flexible Bayesian regression model for the log-excess hazard where the baseline log-excess hazard and any non-linear effects of covariates are modelled using low-rank thin plate splines. Using this type of splines will ensure that the log-likelihood function retains tractability not requiring numerical integration. We demonstrate how to derive posterior distributions for the excess hazard and for net survival, a population-level measure of cancer survival that can be derived from excess hazard models. We illustrate the proposed model using survival data for patients diagnosed with colon cancer during 2009 in London, England.

A Unified Approach to Study the Thermal Dynamics in Multilongitudinal Mode Semiconductor Lasers

2001 ◽  
Vol 20 (2) ◽  
pp. 159-169 ◽  
Author(s):  
M. Ganesh Madhan ◽  
P. R. Vaya ◽  
N. Gunasekaran
Keyword(s):  
Semiconductor Lasers ◽  
Unified Approach ◽  
Thermal Dynamics

The Effect of Partly Missing Covariates on Statistical Power in Randomized Controlled Trials With Discrete-Time Survival Endpoints

Methodology ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 41-60
Author(s):  
Shahab Jolani ◽  
Maryam Safarkhani
Keyword(s):  
Randomized Controlled Trials ◽  
Discrete Time ◽  
Treatment Effect ◽  
Survival Data ◽  
Controlled Trials ◽  
Missing Covariates ◽  
Indicator Method ◽  
Imputation Methods ◽  
Randomized Controlled ◽  
Baseline Covariates

Abstract. In randomized controlled trials (RCTs), a common strategy to increase power to detect a treatment effect is adjustment for baseline covariates. However, adjustment with partly missing covariates, where complete cases are only used, is inefficient. We consider different alternatives in trials with discrete-time survival data, where subjects are measured in discrete-time intervals while they may experience an event at any point in time. The results of a Monte Carlo simulation study, as well as a case study of randomized trials in smokers with attention deficit hyperactivity disorder (ADHD), indicated that single and multiple imputation methods outperform the other methods and increase precision in estimating the treatment effect. Missing indicator method, which uses a dummy variable in the statistical model to indicate whether the value for that variable is missing and sets the same value to all missing values, is comparable to imputation methods. Nevertheless, the power level to detect the treatment effect based on missing indicator method is marginally lower than the imputation methods, particularly when the missingness depends on the outcome. In conclusion, it appears that imputation of partly missing (baseline) covariates should be preferred in the analysis of discrete-time survival data.

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