Piecewise Survival Models: An Application on the COVID-19 Lung Cancer Dataset

Öz

The Cox regression model analyzes the time until an event occurs and is based on the proportional hazards assumption. If this assumption is not met, alternative models should be preferred. In this study, we consider piecewise survival models, which can better reflect time-varying hazard rates. Piecewise survival models divide the survival time into specific intervals and assume that the hazard ratio is constant within each interval. This model can be used as an alternative to the Cox regression model, parametric survival models, and discrete survival models. It is more flexible than parametric models and allows for observing how the hazard ratio changes over time. In this study, piecewise survival models with exponential, Weibull, and frailty terms were analyzed. In the application on lung cancer data, the piecewise Weibull survival model was found to be the most appropriate model for reflecting time-varying hazard ratios.

Anahtar Kelimeler

• Parametric
• Piecewise Exponential Survival Models
• Piecewise Weibull Survival Models
• Frailty Survivals Models

Destekleyen Kurum

The author(s) acknowledge that they received no external funding to support this research.

Etik Beyan

It is declared that scientific and ethical principles were followed during the preparation of this study and that all studies used are stated in the bibliography.

Üstel ve Weibull Parçalı Yaşam Modelleri: COVID-19 Dönemi Akciğer Kanseri Veri Kümesi Üzerine Bir Uygulama

Öz

Cox regresyon modeli, olay gerçekleşene kadar geçen süreyi analiz eder ve orantılı tehlikeler varsayımına dayanır. Bu varsayım sağlanmazsa alternatif modeller tercih edilmelidir. Bu çalışmada, zamanla değişen tehlike oranlarını daha iyi yansıtabilecek parçalı yaşam modelleri ele alınmıştır. Parçalı yaşam modelleri, yaşam süresini belirli aralıklara böler ve her aralıkta tehlike oranının sabit olduğu varsayımına dayanır. Bu model, Cox regresyon modeli, parametrik yaşam modelleri ve kesikli yaşam modellerine alternatif olarak kullanılabilir. Parametrik modellere göre daha esnek bir yapıya sahip olan bu model, tehlike oranının zamanla nasıl değiştiğini gözlemlemeye imkân tanır. Çalışmada, üstel, Weibull ve zayıflık terimli parçalı yaşam modelleri incelenmiştir. Akciğer kanseri verisi üzerinde yapılan uygulamada, parçalı Weibull yaşam modelinin, zamanla değişen tehlike oranlarını yansıtma konusunda en uygun model olduğu belirlenmiştir.

Anahtar Kelimeler

• Parametrik
• Parçalı Üstel Yaşam Modeli
• Parçalı Weibull Yaşam Modeli
• Zayıflık Terimli Yaşam Modeli

Destekleyen Kurum

Bu araştırmayı desteklemek için dış fon kullanılmamıştır.

Etik Beyan

Bu çalışmanın hazırlanma sürecinde bilimsel ve etik ilkelere uyulduğu ve yararlanılan tüm çalışmaların kaynakçada belirtildiği beyan olunur.

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