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? 2023 Elsevier Inc.Objective: The authors aimed to investigate life expectancy after adult cardiac surgery. Setting: Nationwide study including University and non-University hospitals. Participants: Consecutive adult patients who...
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? 2023 Elsevier Inc.Objective: The authors aimed to investigate life expectancy after adult cardiac surgery. Setting: Nationwide study including University and non-University hospitals. Participants: Consecutive adult patients who underwent heart valve and coronary artery surgery from a nationwide administrative registry. Interventions: Surgical procedures on the heart valves and coronary arteries. Methods: The authors estimated the 10-year relative survival of adult patients who underwent surgery for heart valve diseases and coronary artery disease taken from a nationwide administrative registry. Measurements and Results: Overall, data on 415,472 patients were available for this study. Among them, 394,445 (94.9%) survived 90 days after surgery, and their 10-year survival was 58.0% (95% CI 57.8-58.3); the expected survival was 70.1%, and the relative survival was 0.83 (95% CI 0.82-0.83). Patients who underwent surgical repair of the mitral valve and aortic valve had relative survival of 0.96 and 0.92, respectively. Isolated coronary artery bypass grafting had a relative survival of 0.88. Surgical replacement of the heart valves had a relative survival below 0.80. Poor results with relative survival <0.70 were observed after complex cardiac surgery. Relative survival was <0.60 in patients who underwent double- or triple-valve surgery combined with coronary artery surgery. The authors observed markedly lower relative survival among women (0.77, 95% CI 0.77-0.78) compared with men (0.86, 95% CI 0.85-0.86) at 10 years. Such a difference was observed after almost all different procedures. Conclusions: The present findings provided a picture of the real expectation in terms of the late survival of patients after having undergone adult cardiac surgery. This information should be communicated to patients and their relatives before surgery, and it may be relevant in the decision-making process and in planning tertiary prevention.
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Net survival, estimated in a relative survival (RS) or cause-specific survival (CSS) framework, is a key measure of the effectiveness of cancer management. We compared RS and CSS in men with prostate cancer (PCa) according to age ...
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Net survival, estimated in a relative survival (RS) or cause-specific survival (CSS) framework, is a key measure of the effectiveness of cancer management. We compared RS and CSS in men with prostate cancer (PCa) according to age and risk category, using Prostate Cancer data Base Sweden, including 168,793 men younger than age 90 years, diagnosed 1998-2016 with PCa. RS and CSS were compared according to age and risk category based on TNM (tumor, nodes, and metastases) stage, Gleason score, and prostate-specific antigen level. Each framework requires assumptions that are unlikely to be appropriate for PCa. Ten-year RS was substantially higher than CSS in men aged 80-89 with low-risk PCa: 125% (95% confidence interval: 113, 138) versus 85% (95% confidence interval: 82, 88). In contrast, RS and CSS were similar for men under age 70 and for all men with regional or distant metastases. Both RS and CSS produce biased estimates of net survival for men with low-and intermediate-risk PCa, in particular for men over 80. Due to biases, net survival is overestimated in analysis of RS but underestimated in analysis of CSS. These results highlight the importance of evaluating the underlying assumptions for each method, because the "true" net survival is expected to lie between the limits of RS and CSS.
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In the 2000s, the introduction of the tyrosine kinase inhibitor, imatinib, improved the survival outcomes of patients with chronic myeloid leukemia (CML). In Lebanon, we rapidly adopted this treatment strategy. We retrospectively ...
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In the 2000s, the introduction of the tyrosine kinase inhibitor, imatinib, improved the survival outcomes of patients with chronic myeloid leukemia (CML). In Lebanon, we rapidly adopted this treatment strategy. We retrospectively reviewed the medical records of 46 patients diagnosed with CML and treated with front-line imatinib 400 mg/day from 2000 and followed up to 2015. The achievement of a major molecular response and complete cytogenetic response and overall survival, progression-free survival, and event-free survival were similar to previous published data.
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Cryopreservation of ovarian tissue is known to affect follicular survival. Several variables may be responsible for this. Little attention has focused on the effect of the size of the fragment to be cryopreserved. This study was c...
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Cryopreservation of ovarian tissue is known to affect follicular survival. Several variables may be responsible for this. Little attention has focused on the effect of the size of the fragment to be cryopreserved. This study was conducted to assess the effect of the size of the tissue on follicular histology after freezing with 1,2-propanediol. Histological evaluations were performed of control and cryopreserved tissue. Fragments were cut 10 x 3 x 2 mm(3) (2 mm group) or 10 x 3 x 4 mm(3) (4 mm group). Percentages of normal follicles in control fragments cut into 2 and 4 mm slices were 56% and 34%, respectively. The relative risks to obtain normal follicles in the 2 mm and the 4 mm fragments after cryopreservation were 0.63 and 0.47, respectively. Freezing reduced follicle survival to a significantly greater extent in the larger tissue fragments. There is an increased risk of damage to primary and primordial follicles, when the tissue slices are cut with all dimensions larger than 2 mm.
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Net survival, the survival which might occur if cancer was the only cause of death, is a major epidemiological indicator required for international or temporal comparisons. Recent findings have shown that all classical methods use...
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Net survival, the survival which might occur if cancer was the only cause of death, is a major epidemiological indicator required for international or temporal comparisons. Recent findings have shown that all classical methods used for routine estimation of net survival from cancer-registry data, sometimes called "relative-survival methods," provide biased estimates. Meanwhile, an unbiased estimator, the Pohar-Perme estimator (PPE), was recently proposed. Using real data, we investigated the magnitude of the errors made by four "relative-survival" methods (Ederer I, Hakulinen, Ederer II and a univariable regression model) vs. PPE as reference and examined the influence of time of follow-up, cancer prognosis, and age on the errors made. The data concerned seven cancer sites (2,51,316 cases) collected by FRANCIM cancer registries. Net survivals were estimated at 5, 10 and 15 years postdiagnosis. At 5 years, the errors were generally small. At 10 years, in good-prognosis cancers, the errors made in nonstandardized estimates with all classical methods were generally great (+2.7 to +9% points in prostate cancer) and increased in age-class estimations (vs. 5-year ones). At 15 years, in bad- or average-prognosis cancers, the errors were often substantial whatever the nature of the estimation. In good-prognosis cancers, the errors in nonstandardized estimates of all classical methods were great and sometimes very important. With all classical methods, great errors occurred in age-class estimates resulting in errors in age-standardized estimates (+0.4 to +3.2% points in breast cancer). In estimating net survival, cancer registries should abandon all classical methods and adopt the new Pohar-Perme estimator. What's new? "Net survival" refers to the risk of dying from a particular cancer, after all other risks are removed. Unfortunately, due to inherent biases, most of the statistical methods used to estimate net survival are quite inaccurate. In this study, the authors used a new method called the "Pohar-Perme estimator, " (PPE) to analyze data from cancer registries, with various combinations of prognosis and age distribution. They conclude that PPE lacks the biases of the other methods and should become the preferred standard for estimating net survival.
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The number of older adults worldwide is increasing as societies gain success in improving the health and lifespan of their citizens. As a result, increasing numbers of older adults are presenting to the medical community with adva...
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The number of older adults worldwide is increasing as societies gain success in improving the health and lifespan of their citizens. As a result, increasing numbers of older adults are presenting to the medical community with advanced kidney failure. Historically, dialysis treatments were withheld from older adults particularly those with severe co-existing illnesses. This has changed in most parts of the world, and there is now an increasing emphasis on shared decision-making to determine whether dialysis is appropriate and to determine which modality meets the needs, expectations, and desire of patients. Evidence examining the difference in risk for death of older adults treated with hemodialysis (HD) or peritoneal dialysis (PD), and the probability of those treated with PD to transfer to HD among older compared to younger adults, is largely derived from prospective cohort studies or analyses of data from national registries. In such studies, it is difficult to distinguish whether differences in outcomes reflect the effect of dialysis modality or differences in health status of different groups of patients. Longevity and technique survival are important, albeit not the only or most important consideration in such decision-making. Given the risk for bias in observational studies and the profound effect of dialysis modality on patients' lifestyle, the selection of dialysis modality should remain a decision made by the patient, caregivers, and his/her physician after thorough education and review of the available data.
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Farmer profit depends on the number of slaughter rabbits. The improvement of litter size (LS) at birth by two-stage selection for ovulation rate (OR) and LS could modify survival rate from birth to slaughter. This study was aiming...
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Farmer profit depends on the number of slaughter rabbits. The improvement of litter size (LS) at birth by two-stage selection for ovulation rate (OR) and LS could modify survival rate from birth to slaughter. This study was aiming to estimate direct and correlated response on LS traits and peri- and postnatal survival traits in the OR_LS rabbit line selected first only for OR (first period) and then for OR and LS using independent culling levels (second period). The studied traits were OR, LS measured as number of total born, number of kits born alive (NBA) and dead (NBD), and number of kits at weaning (NW) and young rabbits at slaughter (NS). Prenatal survival (LS/OR) and survival at birth (NBA/LS), at weaning (NW/NBA) and at slaughter (NS/NW) were also studied. Data were analysed using Bayesian inference methods. Heritability for LS traits were low, 0.07 for NBA, NW and NS. Survival traits had low values of heritability 0.07, 0.03 and 0.03 for NBA/LS, NW/NBA and NS/NW, respectively. After six generations of selection by OR (first period), a small increase in NBD and a slight decrease in NBA/LS were found. However, no correlated responses on NW/NBA and NS/NW were observed. After 11 generations of two-stage selection for OR and LS (second period), correlated responses on NBA, NW and NS were 0.12, 0.12 and 0.11 kits per generation, respectively, whereas no substantial modifications on NBA/LS, NW/NBA and NS/NW were found. In conclusion, two-stage selection improves the number of young rabbits at slaughter without modifying survival from birth to slaughter.
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Time is an important variable for retailers. The concepts of survival and duration, linked to this time variable, can be very interesting in franchising research. For instance, what are the determinants of the survival of a networ...
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Time is an important variable for retailers. The concepts of survival and duration, linked to this time variable, can be very interesting in franchising research. For instance, what are the determinants of the survival of a network or a store? Which elements decrease the period before franchising or internationalising a network? There is a well adapted but little-exploited methodology in this research area: survival analysis. Consequently, this methodological paper presents in detail survival analysis methodology before giving relevant examples of applications in the franchising field. Managerial implications of these kinds of research are given before the conclusion.
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A crucial component of making individualized treatment decisions is to accurately predict each patient's disease risk. In clinical oncology, disease risks are often measured through time-to-event data, such as overall survival and...
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A crucial component of making individualized treatment decisions is to accurately predict each patient's disease risk. In clinical oncology, disease risks are often measured through time-to-event data, such as overall survival and progression/recurrence-free survival, and are often subject to censoring. Risk prediction models based on recursive partitioning methods are becoming increasingly popular largely due to their ability to handle nonlinear relationships, higher-order interactions, and/or high-dimensional covariates. The most popular recursive partitioning methods are versions of the Classification and Regression Tree (CART) algorithm, which builds a simple interpretable tree structured model. With the aim of increasing prediction accuracy, the random forest algorithm averages multiple CART trees, creating a flexible risk prediction model. Risk prediction models used in clinical oncology commonly use both traditional demographic and tumor pathological factors as well as high-dimensional genetic markers and treatment parameters from multimodality treatments. In this article, we describe the most commonly used extensions of the CART and random forest algorithms to right-censored outcomes. We focus on how they differ from the methods for noncensored outcomes, and how the different splitting rules and methods for cost-complexity pruning impact these algorithms. We demonstrate these algorithms by analyzing a randomized Phase III clinical trial of breast cancer. We also conduct Monte Carlo simulations to compare the prediction accuracy of survival forests with more commonly used regression models under various scenarios. These simulation studies aim to evaluate how sensitive the prediction accuracy is to the underlying model specifications, the choice of tuning parameters, and the degrees of missing covariates.
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Statistical models for survival data are typically nonparametric, for example, the Kaplan-Meier curve. Parametric survival modeling, such as exponential modeling, however, can reveal additional insights and be more efficient than ...
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Statistical models for survival data are typically nonparametric, for example, the Kaplan-Meier curve. Parametric survival modeling, such as exponential modeling, however, can reveal additional insights and be more efficient than nonparametric alternatives. A major constraint of the existing exponential models is the lack of flexibility due to distribution assumptions. A flexible and parsimonious piecewise exponential model is presented to best use the exponential models for arbitrary survival data. This model identifies shifts in the failure rate over time based on an exact likelihood ratio test, a backward elimination procedure, and an optional presumed order restriction on the hazard rate. Such modeling provides a descriptive tool in understanding the patient survival in addition to the Kaplan-Meier curve. This approach is compared with alternative survival models in simulation examples and illustrated in clinical studies.
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