Reducing the First-Type Error Rate of the Log-Rank Test: Asymptotic Time Complexity Analysis of An Optimized Test’s Alternative

Author(s):  
Lubomír Štěpánek ◽  
Filip Habarta ◽  
Ivana Malá ◽  
Luboš Marek
Swiss Surgery ◽  
2000 ◽  
Vol 6 (1) ◽  
pp. 6-10
Author(s):  
Knoefel ◽  
Brunken ◽  
Neumann ◽  
Gundlach ◽  
Rogiers ◽  
...  

Die komplette chirurgische Entfernung von Lebermetastasen bietet Patienten nach kolorektalem Karzinom die einzige kurative Chance. Es gibt jedoch eine, anscheinend unbegrenzte, Anzahl an Parametern, die die Prognose dieser Patienten bestimmen und damit den Sinn dieser Therapie vorhersagen können. Zu den am häufigsten diskutierten und am einfachsten zu bestimmenden Parametern gehört die Anzahl der Metastasen. Ziel dieser Studie war es daher die Wertigkeit dieses Parameters in der Literatur zu reflektieren und unsere eigenen Patientendaten zu evaluieren. Insgesamt konnte von 302 Patienten ein komplettes Follow-up erhoben werden. Die gebildeten Patientengruppen wurden mit Hilfe einer Kaplan Meier Analyse und konsekutivem log rank Test untersucht. Die Literatur wurde bis Dezember 1998 revidiert. Die Anzahl der Metastasen bestätigte sich als ein prognostisches Kriterium. Lagen drei oder mehr Metastasen vor, so war nicht nur die Wahrscheinlichkeit einer R0 Resektion deutlich geringer (17.8% versus 67.2%) sondern auch das Überleben der Patienten nach einer R0 Resektion tendenziell unwahrscheinlicher. Das 5-Jahres Überleben betrug bei > 2 Metastasen 9% bei > 2 Metastasen 36%. Das 10-Jahres Überleben beträgt bislang bei > 2 Metastasen 0% bei > 2 Metastasen 18% (p < 0.07). Die Anzahl der Metastasen spielt in der Prognose der Patienten mit kolorektalen Lebermetastasen eine Rolle. Selbst bei mehr als vier Metastasen ist jedoch gelegentlich eine R0 Resektion möglich. In diesen Fällen kann der Patient auch langfristig von einer Operation profitieren. Das wichtigere Kriterium einer onkologisch sinnvollen Resektabilität ist die Frage ob technisch und funktionell eine R0 Resektion durchführbar ist. Ist das der Fall, so sollte auch einem Patienten mit mehreren Metastasen die einzige kurative Chance einer Resektion nicht vorenthalten bleiben.


1986 ◽  
Vol 56 (03) ◽  
pp. 268-270 ◽  
Author(s):  
M Morfini ◽  
D Rafanelli ◽  
G Longo ◽  
A Messori ◽  
P Rossi Ferrini

SummaryPost-infusion hepatitis is known to occur very frequently in haemophiliacs after treatment with unheated commercial clotting factor concentrates, obtained from large plasma donation pool. On the contrary, single-donor cryoprecipitate is likely to carry a lower risk of transmitting hepatitis.To evaluate this hypothesis, we retrospectively reviewed the medical records of 25 first infused haemophiliacs (from 1981 to 1984) treated with unheated commercial clotting factor concentrates (n = 19) or cryoprecipitate (n = 6).The hepatitis-free interval after the beginning of therapy was expressed as exposure days. The end point of each patient, i.e. the hepatitis occurrence, was defined as an increase of aminotransferases (ALT and AST) and/or the seroconversion of HBV-markers, which were checked every three months.The life-table method and log-rank test showed that cryo-precipitates had a significantly longer hepatitis-free interval (p = 0.0131, log-rank test) and a lower risk of transmitting hepatitis (p = 0.01-0.05, life-table method) than the commercial concentrates. However, the safety of cryoprecipitate therapy was shown to cover only a few exposure days, and so the real advantage of this product depends on the bleeding frequency of the patient concerned.We believe that these methods and our findings may be useful to assess and compare the safety of the new “heat-treated” clotting factor concentrates.


2018 ◽  
Vol 15 (8) ◽  
pp. 751-763 ◽  
Author(s):  
Antonio Martinez-Torteya ◽  
Hugo Gomez-Rueda ◽  
Victor Trevino ◽  
Joshua Farber ◽  
Jose Tamez-Pena ◽  
...  

Background: Diagnosing Alzheimer’s disease (AD) in its earliest stages is important for therapeutic and support planning. Similarly, being able to predict who will convert from mild cognitive impairment (MCI) to AD would have clinical implications. Objectives: The goals of this study were to identify features from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database associated with the conversion from MCI to AD, and to characterize the temporal evolution of that conversion. Methods: We screened the publically available ADNI longitudinal database for subjects with MCI who have developed AD (cases: n=305), and subjects with MCI who have remained stable (controls: n=250). Analyses included 1,827 features from laboratory assays (n=12), quantitative MRI scans (n=1,423), PET studies (n=136), medical histories (n=72), and neuropsychological tests (n=184). Statistical longitudinal models identified features with significant differences in longitudinal behavior between cases and matched controls. A multiple-comparison adjusted log-rank test identified the capacity of the significant predictive features to predict early conversion. Results: 411 features (22.5%) were found to be statistically different between cases and controls at the time of AD diagnosis; 385 features were statistically different at least 6 months prior to diagnosis, and 28 features distinguished early from late conversion, 20 of which were obtained from neuropsychological tests. In addition, 69 features (3.7%) had statistically significant changes prior to AD diagnosis. Conclusion: Our results characterized features associated with disease progression from MCI to AD, and, in addition, the log-rank test identified features which are associated with the risk of early conversion.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Brandao ◽  
J Goncalves Almeida ◽  
J Monteiro ◽  
F Montenegro Sa ◽  
P Fonseca ◽  
...  

Abstract Background Upgrade to resynchronization therapy (CRT) from conventional pacemaker (P) or defibrillator (D) is common practice in Europe. However, guidelines (GL) are discordant: Pacing GL give a class I recommendation, while Heart Failure (HF) GL provide a class IIb indication. Previous studies suggested worse outcomes in upgraded patients (pts). Aim To compare response rate and clinical outcomes in a cohort of pts receiving de novo or upgrade to CRT. Methods Single-center retrospective study of consecutive pts submitted to CRT implantation (2007–2017). Major adverse cardiac events (MACE) included HF hospitalization (HHF) or all-cause mortality. Clinical response was defined as New York Heart Association class improvement without MACE in the first year of follow-up (FU). Left ventricle end-systolic volume reduction of &gt;15% denoted echocardiographic (echo) response. Survival analysis with Kaplan-Meier method and Log-rank test was performed. Propensity-score matching (PSM) analysis was made to adjust for possible confounder variables. Results 230 CRT recipients (70.9% male, mean age 67±11 years, 71.5% non-ischemic cardiomyopathy, 39.6% CRT-P) were included, of whom 46 (20%) underwent an upgrade. Upgraded pts were older (69.8 vs 65.9 years, p=0.015), with higher rates of permanent atrial fibrillation (37.0% vs 12.7%, p=0.001), moderate to severe valve disease (45.7% vs 22.3%, p=0.002), chronic kidney disease (37.0% vs 17.2%, p=0.005) and treatment with mineralocorticoid receptor antagonists (79.1% vs 52.0%, p=0.002). They were more likely to receive CRT-P (65.2% vs 33.2%, p&lt;0.001) and CRT-D were more often implanted for secondary prevention (60.0% vs 17.9%, p=0.001). No differences emerged in procedural complications, clinical (74.4% vs 71.4%, p=0.712) or echo (66.7% vs 69.7%, p=0.822) response rates. During a median FU of 3±4 years, all-cause mortality was similar among groups (Log Rank test, p=0.522, unadjusted hazard ratio [HR] 1.25, confidence interval [CI] 95% 0.62–2.49, p=0.534). There was a statistical tendency for higher MACE rate in the upgrade group (Log Rank test, p=0.064, HR 1.66, CI 95% 0.95–2,91, p=0.076). No differences were found in lead dislodgement (10.9% vs 7.1%, p=0.368) or endocarditis (2.2% vs 4.3%, p=0.692) rates. PSM analysis identified 88 matched pairs (46 upgrade/42 de novo pts). In this cohort, all-cause mortality (Log Rank test, p=0.77, HR 0.89, CI 95% 0.39–2.03, p=0.78) and MACE (Log Rank test, p=0.36, HR 1.38, CI 95% 0.68–2.81, p=0.37) were comparable between groups [graph no. 1]. Conclusion Upgrade to CRT was similar to de novo implantation in terms of complications and clinical and echo response, in this cohort. The risk for MACE and mortality was also comparable. Graph 1 Funding Acknowledgement Type of funding source: None


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1606.2-1606
Author(s):  
L. Verardi ◽  
E. De Lorenzis ◽  
G. Natalello ◽  
L. Gigante ◽  
U. La Porta ◽  
...  

Background:Systemic Sclerosis (SSc) is characterized by an increased incidence of macro- and microvascular complications. Current evidences on efficacy, safety and tolerability of acetylsalicylic acid (ASA) in SSc patients are limited, and the indication to this treatment is based on the experience of each single centre or physician. Esophagus and stomach are the portions of the digestive tract that are more frequently affected by adverse events due to ASA exposure.Objectives:We evaluated the incidence of adverse events associated with low-dose ASA treatment in a cohort of patients affected by SSc.Methods:Demographic data and disease features of 302 patients affected by SSc treated with low-dose ASA were collected and patients were followed-up for a median period of 6.9 years (range: 0-20 years). The proportion of patients taking ASA for secondary prevention for cardiovascular disease was also noted. The incidence of discontinuation of the drug, gastrointestinal intolerance, bleeding and death in the observation period was recorded.Results:Patients had a median age of 54.0 years (19.6-89.4); 91.9% were female, 13.2% were smokers and 44.0% had a BMI≥30Kg/m2. The prevalence of ischemic heart disease, peripheral vascular disease and stroke was of 8.6%, 5.3% and 3.3%, respectively; 48.7% of the patient took ASA in primary cardiovascular prevention. Therapy started after a median disease duration of 4.8 years (range: 0.0- 30.1 years) since the first non-Raynaud symptom and 56.6% of patients had an early disease (less than three years of disease duration). During the observation period, 30 patients (14.3 per 1000 person-years) discontinued ASA after an average period of assumption of 4.6 years (range: 0.3-18.0 years). The main adverse events were heartburn, dyspepsia and hematochezia, recorded in 18 patients (8.6 per 1000 person-years). Eight of them (3.8 per 1000 person-years) had evidence of digestive tract bleeding. Five patients (2.4 per 1000 person-years) discontinued ASA due to recurrent epistaxis. Twenty-eight patients (13.4 per 1000 person-years) died in the follow-up period, 16 of these (7.6 per 1000 person-years) because of SSc-related causes. None of them had evidence of major bleeding. We used Kaplan-Meier analysis to evaluate the incidence of ASA discontinuation. The history of digital ulcers (Log rank test X24.7, p=0.037) and male sex (Log rank test X24.3, p=0.03) were associated with a higher cumulative ASA discontinuation rate due to gastrointestinal intolerance.Conclusion:In our cohort of SSc patients, ASA resulted safe and well tolerated in most cases, despite the risk of gastroesophageal abnormalities due to disease. Although this comforting results, taking in account the lack of controlled-randomized trials about efficacy and safety, the choice to start antiplatelet therapy with ASA should be mandatorily preceded by a careful evaluation of risks and benefits. Furthermore, an attentive monitoring for possible adverse effects is needed during ASA treatment. Patients with digital ulcers and male sex could present less drug tolerability.References:[1]Valentini G et al. Ann Rheum Dis 2019. Beckett VL et al. Arthritis Rheum 1984. Kavian N et al. Vascul Pharmacol 2015. Lavie CJ et al. Curr Probl Cardiol 2017.Disclosure of Interests:Lucrezia Verardi: None declared, Enrico De Lorenzis: None declared, Gerlando Natalello: None declared, Laura Gigante: None declared, Umberto La Porta: None declared, Elisa Gremese Consultant of: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Merck Sharp & Dohme, Novartis, Sanofi, UCB, Roche, Pfizer, Speakers bureau: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Merck Sharp & Dohme, Novartis, Sanofi, UCB, Roche, Pfizer, Silvia Laura Bosello Speakers bureau: Abbvie, Pfizer, Boehringer


Author(s):  
Nanako Koyama ◽  
Chikako Matsumura ◽  
Yuuna Tahara ◽  
Morito Sako ◽  
Hideo Kurosawa ◽  
...  

Abstract Purpose The aims of the present study were to investigate the symptom clusters in terminally ill patients with cancer using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 15 Palliative Care (EORTC QLQ-C15-PAL), and to examine whether these symptom clusters influenced prognosis. Methods We analyzed data from 130 cancer patients hospitalized in the palliative care unit from June 2018 to December 2019 in an observational study. Principal component analysis was used to detect symptom clusters using the scored date of 14 items in the QLQ-C15-PAL, except for overall QOL, at the time of hospitalization. The influence of the existence of these symptom clusters and Palliative Performance Scale (PPS) on survival was analyzed by Cox proportional hazards regression analysis, and survival curves were compared between the groups with or without existing corresponding symptom clusters using the log-rank test. Results The following symptom clusters were identified: cluster 1 (pain, insomnia, emotional functioning), cluster 2 (dyspnea, appetite loss, fatigue, and nausea), and cluster 3 (physical functioning). Cronbach’s alpha values for the symptom clusters ranged from 0.72 to 0.82. An increased risk of death was significantly associated with the existence of cluster 2 and poor PPS (log-rank test, p = 0.016 and p < 0.001, respectively). Conclusion In terminally ill patients with cancer, three symptom clusters were detected based on QLQ-C15-PAL scores. Poor PPS and the presence of symptom cluster that includes dyspnea, appetite loss, fatigue, and nausea indicated poor prognosis.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Matsushita ◽  
B Marchandot ◽  
M Kibler ◽  
C Sato ◽  
J Heger ◽  
...  

Abstract Introduction Paravalvular leakage (PVL) following transcatheter aortic valve replacement (TAVR) is associated with greater mortality. In clinical practice, determining PVL severity after TAVR remains challenging and often requires multiparametric assessment. Purpose This study sought to evaluate the respective value of various modalities of PVL assessments, including transthoracic echocardiography (TTE), cine-angiography, aortic regurgitation index (ARI), and closure time with adenosine diphosphate (CT-ADP), in the prediction of adverse clinical outcomes. Methods We included 1044 patients from our prospective TAVR registry between February 2010 and May 2019. Major adverse cardiac and cerebrovascular events (MACCE) was defined as a composite of all-cause death, myocardial infarction, stroke, and heart failure hospitalization within 1-year. Established cutoff values of ARI (&lt;25) and CT-ADP (&gt;180 sec) were used to assess the presence of PVL after TAVR. Results Moderate to severe PVL occurred in 14.2% and 5.2% of patients as measured by TTE and angiography. The rate of patients with ARI &lt;25 and CT-ADP &gt;180 sec were 36.5% and 24.9%, respectively. Among the four modalities, PVL evaluated by angiography predicted poorer clinical outcomes (Log rank test; p=0.001), whereas TTE, ARI &lt;25, and CT-ADP &gt;180 sec were not associated with 1-year MACCE. By multivariate Cox regression analysis, moderate to severe PVL by angiography was an independent predictor of 1-year MACCE (hazard ratio: 1.96; 95% confidence interval: 1.22–3.00; p=0.007). Conclusions Paravalvular leakage measured by angiography was evidenced as the most meaningful modality in the prediction of adverse clinical outcomes. Future multicenter studies are warranted to ensure these findings in the current TAVR era. Figure 1 Funding Acknowledgement Type of funding source: None


Author(s):  
Khoa Pham ◽  
Micah J Maxwell ◽  
Heather Sweeney ◽  
Jesse Alt ◽  
Rana Rais ◽  
...  

Abstract Medulloblastoma is the most common malignant pediatric brain tumor. Amplification of c-MYC is a hallmark of a subset of poor-prognosis medulloblastoma. MYC upregulates glutamine metabolism across many types of cancer. We modified the naturally occurring glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) by adding 2 promoeities to increase its lipophilicity and brain penetration creating the prodrug isopropyl 6-diazo-5-oxo-2-(((phenyl (pivaloyloxy) methoxy) - carbonyl) amino) hexanoate, termed JHU395. This prodrug was shown to have a 10-fold improved CSF-to-plasma ratio and brain-to-plasma ratio relative to DON. We hypothesized that JHU395 would have superior cell penetration compared with DON and would effectively and more potently kill MYC-expressing medulloblastoma. JHU395 treatment caused decreased growth and increased apoptosis in multiple human high-MYC medulloblastoma cell lines at lower concentrations than DON. Parenteral administration of JHU395 in Nu/Nu mice led to the accumulation of micromolar concentrations of DON in brain. Treatment of mice bearing orthotopic xenografts of human MYC-amplified medulloblastoma with JHU395 increased median survival from 26 to 45 days compared with vehicle control mice (p &lt; 0.001 by log-rank test). These data provide preclinical justification for the ongoing development and testing of brain-targeted DON prodrugs for use in medulloblastoma.


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