Book ChapterDOI
Nonparametric Estimation from Incomplete Observations
Edward L. Kaplan,Paul Meier +1 more
TLDR
In this article, the product-limit (PL) estimator was proposed to estimate the proportion of items in the population whose lifetimes would exceed t (in the absence of such losses), without making any assumption about the form of the function P(t).Abstract:
In lifetesting, medical follow-up, and other fields the observation of the time of occurrence of the event of interest (called a death) may be prevented for some of the items of the sample by the previous occurrence of some other event (called a loss). Losses may be either accidental or controlled, the latter resulting from a decision to terminate certain observations. In either case it is usually assumed in this paper that the lifetime (age at death) is independent of the potential loss time; in practice this assumption deserves careful scrutiny. Despite the resulting incompleteness of the data, it is desired to estimate the proportion P(t) of items in the population whose lifetimes would exceed t (in the absence of such losses), without making any assumption about the form of the function P(t). The observation for each item of a suitable initial event, marking the beginning of its lifetime, is presupposed. For random samples of size N the product-limit (PL) estimate can be defined as follows: L...read more
Citations
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Journal ArticleDOI
Prognostic significance of the MIB-1 proliferation index for patients with squamous cell carcinoma of the esophagus
Emile M. Youssef,Tsutomu Matsuda,Nobuyasu Takada,Harushi Osugi,Masayuki Higashino,Hiroaki Kinoshita,Tomoyuki Watanabe,Yasunori Katsura,Hideki Wanibuchi,Shoji Fukushima +9 more
TL;DR: The aim of this study was to investigate whether any correlation exits between the MIB‐1 proliferation index and various clinicopathologic parameters in squamous cell carcinomas of the esophagus from 72 patients.
Journal ArticleDOI
Perioperative and long-term results after electrophysiologically directed ventricular surgery for recurrent ventricular tachycardia.
TL;DR: Inadequate endocardial resection was a significant predictor of arrhythmia recurrence and poor systolic function of the nonaneurysmal ventricular segments was the strongest and the only independent predictor of operative mortality among the clinical, hemodynamic, angiographic and electrophysiologic variables analyzed by stepwise logistic regression.
Journal ArticleDOI
Oral hygiene, periodontal conditions and carious lesions in patients treated with dental bridges. A 15-year clinical and radiographic follow-up study.
TL;DR: A longitudinal study, extending over a period of 15 years, was carried out in a group of 102 patients who received 108 bridges made by the senior students at the Dental Faculty, University of Oslo, in 1967/68 as mentioned in this paper.
Journal ArticleDOI
Phase II study of topotecan in metastatic non-small-cell lung cancer.
Thomas J. Lynch,Leslie A. Kalish,Gary M. Strauss,Anthony D. Elias,Arthur T. Skarin,Lawrence N. Shulman,Mitchell C. Posner,E Frei rd +7 more
TL;DR: No objective clinical responses were observed despite producing high-grade neutropenia in untreated patients with metastatic NSCLC, and the median survival duration of 7.6 months for 20 patients treated with an agent that failed to produce any obvious clinical responses compares favorably to the survival obtained with combinations of existing agents.
Journal ArticleDOI
Late Clonal Complications in Severe Aplastic Anemia
TL;DR: One hundred and seventy patients with severe aplastic anemia treated in Basel, from 1976 to 1992, underwent bone marrow transplantation and antilymphocyte globulin (ALG) therapy and none of the patients treated with BMT developed MDS or PNH.
References
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Journal ArticleDOI
Survival Curve for Cancer Patients Following Treatment
Joseph Berkson,Robert P. Gage +1 more
TL;DR: A simple function, in terms of two physically meaningful parameters, has been evolved, which fits survivorship data very well and can be used to compare succinctly the mortality of two groups, different in respect of treatment, type of cancer, or other characteristics.
Journal ArticleDOI
An analysis of some failure data
TL;DR: The rationale and statistical techniques employed in the analysis of some failure data obtained from operations performed by machines and people are summarized and the agreement between theory and data is evaluated.