scholarly journals Asymptotic convergence in distribution of the area bounded by prevalence-weighted Kaplan–Meier curves using empirical process modelling

2018 ◽  
Vol 5 (11) ◽  
pp. 180496
Author(s):  
Aaron Heuser ◽  
Minh Huynh ◽  
Joshua C. Chang

The Kaplan–Meier product-limit estimator is a simple and powerful tool in time to event analysis. An extension exists for populations stratified into cohorts where a population survival curve is generated by weighted averaging of cohort-level survival curves. For making population-level comparisons using this statistic, we analyse the statistics of the area between two such weighted survival curves. We derive the large sample behaviour of this statistic based on an empirical process of product-limit estimators. This estimator was used by an interdisciplinary National Institutes of Health–Social Security Administration team in the identification of medical conditions to prioritize for adjudication in disability benefits processing.

1993 ◽  
Vol 108 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Kerry D. Olsen ◽  
Jon V. Thomas ◽  
Lawrence W. Desanto ◽  
Vera J. Suman

Select early glottic carcinomas in patients with normal vocal cord mobility can be successfully treated with cordectomy, performed either endoscopicaliy or by means of an open operation (laryngofissure-cordectomy). From 1976 to 1986, 95 patients underwent cordectomy at our institution. There were 88 men and 7 women, with an age range at the time of surgery of 27 to 84 years. A laryngofissure was used to perform a cordectomy in 61 patients and an endoscopic approach was used in 34. The median number of days in the hospital for the endoscopic group was 2, and for the laryngofissure group it was 6. The Kaplan-Meier product-limit method showed the probability of no recurrence in the first 3 years after an endoscopic cordectomy was 0.9099, and in the laryngofissure-cordectomy group it was 0.9502. To date, there have been four recurrences (11.8%) in the endoscopic group and three (4.9%) in the laryngofissure group. Only one patient with recurrent tumor is known to have died of the cancer. Laryngectomy was necessary for ultimate control in three patients. The Kaplan-Meier survival curve for the 95 patients was the same as that for a sex- and age-matched control group. Cordectomy is an effective treatment option that results in minimal morbidity for select early glottic carcinomas.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wang Miao ◽  
Junshuang Guo ◽  
Shuyu Zhang ◽  
Nannan Shen ◽  
Xiaoping Shang ◽  
...  

Objective: There is currently no effective treatment for Japanese encephalitis, which has a high rate of morbidity and mortality. This study assessed the effectiveness of a ganciclovir, methylprednisolone, and immunoglobulin combination (TAGMIC) therapy in decreasing cognitive impairment and mortality among patients with Japanese encephalitis.Methods: We retrospectively assessed the clinical data of 31 patients diagnosed with Japanese encephalitis, who were admitted to an intensive care unit. Patients were divided into the TAGMIC and non-TAGMIC group according to their treatment regime. We compared the 60-day, 6-month, and overall mortality and survival curves between groups. We also compared Barthel Index scores, Montreal Cognitive Assessment (MoCA) scores, and diffusion tensor imaging (DTI) results.Results: There was no significant difference in the 30-day mortality rate or Kaplan–Meier survival curve between groups. The 60-day, 6-month, and overall mortality rates in the TAGMIC group were significantly reduced (P = 0.043, P = 0.018, and P = 0.018, respectively) compared with the non-TAGMIC group (0, 0, 0 vs. 31.25, 37.5, 37.5%, respectively). The 60-day, 6-month, and overall Kaplan–Meier survival curves were significantly different between groups (P = 0.020, P = 0.009, P = 0.009, respectively). There was no significant difference in the Barthel Index scores of surviving patients. Among the five patients who underwent MoCA and DTI, four had a score of 0/5 for delayed recall (no cue), while the remaining patient had a score of 2/5. All five patients were able to achieve a score of 5/5 with classification and multiple-choice prompts, and had sparse or broken corpus callosum (or other) fibre bundles.Conclusion: TAGMIC treatment can reduce mortality due to severe Japanese encephalitis. The memory loss of surviving patients is mainly due to a disorder of the memory retrieval process, which may be related to the breakage of related fibre bundles.


2021 ◽  
Vol 49 (1) ◽  
pp. 030006052098154
Author(s):  
Xin Yuan ◽  
Yize Zhang ◽  
Zujiang Yu

Objective To investigate the association between microRNA-3615 (miR-3615) expression and the prognosis and clinicopathological features in patients with hepatocellular carcinoma (HCC). Methods We obtained clinicopathological and genomic data and prognostic information on HCC patients from The Cancer Genome Atlas (TCGA) database. We then analyzed differences in miR-3615 expression levels between HCC and adjacent tissues using SPSS software, and examined the relationships between miR-3615 expression levels and clinicopathological characteristics. We also explored the influence of miR-3615 expression levels on the prognosis of HCC patients using Kaplan–Meier survival curve analysis. Results Based on data for 345 HCC and 50 adjacent normal tissue samples, expression levels of miR-3615 were significantly higher in HCC tissues compared with adjacent tissues. MiR-3615 expression levels in HCC patients were negatively correlated with overall survival time and positively correlated with high TNM stage, serum Ki-67 expression level, and serum alpha-fetoprotein level. There were no significant correlations between miR-3615 expression and age, sex, and pathological grade. Conclusion MiR-3615 may be a promising new biomarker and prognostic factor for HCC.


2020 ◽  
pp. 1-9
Author(s):  
Dong Zhao ◽  
Keming Yang ◽  
Wei Feng ◽  
Shoujun Li ◽  
Jun Yan ◽  
...  

Abstract Objective: This study aimed to investigate the association between long-term survival and different management of major aortopulmonary collateral arteries in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries. Methods: From November, 2009 to October, 2018, a total of 98 consecutive patients with pulmonary atresia, ventricular septal defect, major aortopulmonary collateral arteries, and hypoplastic pulmonary arteries treated with modified Blalock–Taussig shunt or right ventricle–pulmonary artery connection were included. Fifty-five patients who received occlusion or ligation of major aortopulmonary collateral arteries during or after palliative procedure were occlusion group, and the other 43 patients were no occlusion group. The early and late outcomes were compared. Results: The mean duration of follow-up was 30.9 months in no occlusion group and 49.8 months in the occlusion group (p < 0.001). Multivariate analysis showed that only no occlusion of major aortopulmonary collateral arteries was predictive of total mortality (Hazard Ratio: 4.42, 95% CI: 1.27 to 15.42, p = 0.02). The Kaplan–Meier survival curves confirmed that patients without occlusion of major aortopulmonary collateral arteries demonstrated worse survival as compared with the occlusion group (p = 0.013). The Kaplan–Meier survival curves of patients who underwent different palliative procedures showed no differences. Conclusions: For patients with pulmonary atresia, ventricular septal defect and major aortopulmonary collateral arteries when a primary repair is not feasible, those without occlusion of major aortopulmonary collateral arteries have a higher risk of death following an initial palliative procedure compared with patients who underwent occlusion of major aortopulmonary collateral arteries. The occlusion of major aortopulmonary collateral arteries is not associated with a higher rate of complete repair or better improvement of pulmonary artery growth.


2021 ◽  
Vol 2 (3) ◽  
pp. 253-263
Author(s):  
Het Patel ◽  
Nikhil Agrawal ◽  
Voravech Nissaisorakarn ◽  
Ridhi Gupta ◽  
Francesca Cardarelli

Malignancy is the third major cause of death among transplant recipients. Patient and kidney transplant outcomes after the diagnosis of malignancy are not well described. We reviewed incidences and outcomes of colorectal, lung, PTLD, and renal malignancy after transplant among patients who received a transplant from January 2000 to December 2018 using the UNOS/OPTN database. Incidence of each malignancy was measured at 5 years and 10 years of transplant. The Kaplan–Meier curve was used for time-to-event analysis (graft and patient outcomes). Additionally, we sought to identify the causes of graft failure among these recipients. We found that 12,764 (5.5%) patients suffered malignancy, excluding squamous and basal cell skin carcinoma after transplant. During the first 5 years of transplant, incidence of colorectal, lung, PTLD, and renal malignancies was 2.99, 9.21, 15.61, and 8.55 per 10,000 person-years, respectively. Rates of graft failure were 10.3%, 7.6%, 19.9%, and 18.8%, respectively, among these patients at 5 years. Mortality rate was highest among patients who suffered lung malignancy (84%), followed by colorectal (61.5%), PTLD (49.1%), and renal (35.5%) at 5 years after diagnosis of malignancy. In conclusion, kidney transplant recipients diagnosed with lung malignancy have the lowest graft survival, compared to PTLD, colorectal, and renal malignancy. PTLD has the highest incidence rate in the first 5 years of transplant.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Janne J. Näppi ◽  
Tomoki Uemura ◽  
Chinatsu Watari ◽  
Toru Hironaka ◽  
Tohru Kamiya ◽  
...  

AbstractThe rapid increase of patients with coronavirus disease 2019 (COVID-19) has introduced major challenges to healthcare services worldwide. Therefore, fast and accurate clinical assessment of COVID-19 progression and mortality is vital for the management of COVID-19 patients. We developed an automated image-based survival prediction model, called U-survival, which combines deep learning of chest CT images with the established survival analysis methodology of an elastic-net Cox survival model. In an evaluation of 383 COVID-19 positive patients from two hospitals, the prognostic bootstrap prediction performance of U-survival was significantly higher (P < 0.0001) than those of existing laboratory and image-based reference predictors both for COVID-19 progression (maximum concordance index: 91.6% [95% confidence interval 91.5, 91.7]) and for mortality (88.7% [88.6, 88.9]), and the separation between the Kaplan–Meier survival curves of patients stratified into low- and high-risk groups was largest for U-survival (P < 3 × 10–14). The results indicate that U-survival can be used to provide automated and objective prognostic predictions for the management of COVID-19 patients.


1996 ◽  
Vol 59 (1) ◽  
pp. 16-23 ◽  
Author(s):  
R. H. LINTON ◽  
W. H. CARTER ◽  
M. D. PIERSON ◽  
C. R. HACKNEY ◽  
J. D. EIFERT

The heat resistance of Listeria monocytogenes was determined in infant formula for all possible combinations of temperature (50, 55, and 60°C), pH level (5, 6, and 7), and NaCl concentration (0, 2, and 4%). Survival curves were fit using nonlinear regression with a Gompertz equation. The Gompertz equation was flexible enough to fit the three most commonly observed survival curves: linear curves, those with an initial lag region followed by a linear region, and sigmoidal shaped. Parameter estimates obtained by the method of nonlinear least squares were used to describe the effect(s) of different heating treatments on the lag region, death rate, and tailing region of survival curves. These estimates were further used to predict single and interactive effects of temperature, pH, and percentage of NaCl on the log of the surviving fraction (LSF) of bacteria. Interactions among these variables significantly (P ≤ .05) affected the LSF. Generally, increased pH or NaCl concentration lead to an increased LSF, whereas increased time or temperature lead to a decreased LSF. All multiple-factor interactions significantly (P ≤ .05) affected the LSF. The correlation of observed LSF versus predicted LSF (R2 = .92) indicated that the estimated Gompertz equation was in close agreement with the observation. This study demonstrated that the Gompertz equation and nonlinear regression can be used as an effective means to predict survival curve shape and response to heat of L. monocytogenes under many different environmental conditions.


2008 ◽  
Vol 99 (1) ◽  
pp. 65-72 ◽  
Author(s):  
N.N. Gómez ◽  
R.C. Venette ◽  
J.R. Gould ◽  
D.F. Winograd

AbstractPredictions of survivorship are critical to quantify the probability of establishment by an alien invasive species, but survival curves rarely distinguish between the effects of temperature on development versus senescence. We report chronological and physiological age-based survival curves for a potentially invasive noctuid, recently described as Copitarsia corruda Pogue & Simmons, collected from Peru and reared on asparagus at six constant temperatures between 9.7 and 34.5°C. Copitarsia spp. are not known to occur in the United States but are routinely intercepted at ports of entry. Chronological age survival curves differ significantly among temperatures. Survivorship at early age after hatch is greatest at lower temperatures and declines as temperature increases. Mean longevity was 220 (±13 SEM) days at 9.7°C. Physiological age survival curves constructed with developmental base temperature (7.2°C) did not correspond to those constructed with a senescence base temperature (5.9°C). A single degree day survival curve with an appropriate temperature threshold based on senescence adequately describes survivorship under non-stress temperature conditions (5.9–24.9°C).


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 180-181
Author(s):  
L. Chatzis ◽  
V. Pezoulas ◽  
A. Goules ◽  
I. Stergiou ◽  
C. Mavragani ◽  
...  

Background:Sjögren’s Syndrome (SS) is a chronic systemic autoimmune disease of unknown etiology, carrying the highest lymphoma risk among autoimmune diseases, with significant impact on mortality and morbidity of patients.Objectives:To describe: i) the clinical phenotype of SS, ii) the histologic type, stage, treatment options regarding lymphomas and iii) the prognosis of patients with SS related lymphoproliferative disorders.Methods:Eight hundred and fifteen consecutive SS patients’ records from a single center fulfilling the 2016 ACR/EULAR were reviewed retrospectively for the purpose of this study. One hundred twenty-one patients with a diagnosis of non-Hodgkin Lymphoma (NHL) were identified and enrolled in the study population. Cumulative clinical, laboratory and histologic data were recorded and overall survival as well as event free survival curves were constructed using the Kaplan-Meier method. An event was defined as a disease progression, lymphoma relapse, treatment failure, histologic transformation, development of a 2nd lymphoma or death from any cause.Results:From 121 pSS patients with lymphoma the most common histologic type encountered was MALT lymphoma (92/121, 76,0%) followed by DLBCL (11/121, 9.0%) and NMZL (8/119, 6.6%). The remaining 10 patients had various lymphomas of B (follicular, lymphoplasmacytic, chronic lymphocytic leukemia} and T cell origin (peripheral T cell lymphoma not otherwise specified, primary cutaneous T cell lymphoma, angioimmunoblastic t-cell lymphoma). Permanent salivary gland enlargement (66.1%, 80/121), palpable purpura (34,7% 42/121), peripheral nervous involvement (9,9%, 12/121), interstitial lung disease (8,2%, 10/121) presence of serum cryoglobulins (38,7%, 43/111) and C4 hypocomplementemia (69,8% 81/116) present at least 1 year before the development of lymphoma were the main pSS related features. The median age at lymphoma diagnosis was 58 years old (range 29-82) while MALT lymphomas developed earlier compared to DLBCL from pSS diagnosis (8 vs 3 OR= 3.84, 95%CI: 0.29 to 10.46; p=0.0266). The commonest biopsy proven extranodal sites included the labial minor salivary (43,8% patients) and parotid glands (30,5%) while 11% of patients had more than 1 extranodal sites affected. Bone marrow involvement was evident in 24,3% of patients (29/119) while nodal involvement in 35,5% (42/118). The majority of patients (65%) had limited disease (stage I or II). A watch and wait therapeutic policy was chosen in 40 patients while the rest received rituximab with or without chemotherapy. The 10-year survival and event free rates were 79% and 45,5% for MALT lymphomas, 40,9% and 24,2% for DLBCL and 46% and 31% for NMZL respectively (Figure 1). The Mantel-Cox log-rank comparison of the overall survival curves revealed a statistically significant difference (p=0.0016) among lymphoma subtypes.Figure 1.Overall and event free survival of SS-associated lymphoma patients. A. Kaplan-Meier overall survival analysis. B. A Kaplan-Meier event free survival analysis.Conclusion:This is the largest single center series of SS- associated lymphoma patients, providing a detailed description of SS and lymphoma related features, combined with a 10-year survival and event free curves for the first time in the literature.Disclosure of Interests:None declared.


Author(s):  
Minling Liu ◽  
Lei Li ◽  
Shan Huang ◽  
Xiaofen Pan ◽  
Huiru Dai ◽  
...  

Background: Triple-negative breast cancer (TNBC) is a highly aggressive malignancy with poor prognosis. Therefore, it is imperative to develop new prognostic or therapeutic biomarkers for TNBC. Objective: To explore the prognostic and therapeutic values of autophagy-related genes (ARGs) in TNBC. Methods: Overall, 157 TNBC patients’ data were obtained from The Cancer Genome Atlas database, and the ARGs were acquired from the Human Autophagy Database. Differentially expressed ARGs (DEGs) between tumor and normal tissues were identified and the prognostic ARGs were developed using R software. Kaplan–Meier survival curves and receiver operating characteristic (ROC) curves were both used to evaluate the accuracy of the signature. Patents about prognostic ARGs were reviewed through Worldwide Espacenet® and Patentscope®. Results: We obtained 28 DEGs and two prognostic ARGs (EIF4EBP1 and PARP1). The Kaplan–Meier survival curves showed that the survival rate of patients with low 2-ARG signature risk score was significantly higher than that of patients with high risk score (P=0.003). ROC at 5 years indicated that the signature had good prognostic accuracy (AUC=0.929). The signature was independent of T, N, M, and TNM stage (P<0.05). Patent review suggested that many mTOR inhibitors alone or in combination with another anticancer agent have been provided for treatment of many cancers and shown promising results. No drug patents about PARP1 overexpression were disclosed. Conclusion: We developed a 2-ARG signature (EIF4EBP1 and PARP1) which was an independent prognostic biomarker for TNBC. As EIF4EBP1 was upregulated in TNBC, mTOR inhibitors which blocked the mTOR/4EBP1/eIF4E pathway may be a promising therapeutic strategy for TNBC.


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