PENDEKATAN HIERARCHICAL LIKELIHOOD UNTUK MODEL LOGNORMAL FRAILTY SATU KOMPONEN DALAM ANALISIS DATA SURVIVAL DUA LEVEL; HIERARCHICAL LIKELIHOOD APPROACH FOR ONE-COMPONENT LOGNORMAL FRAILTY MODEL IN TWO- LEVEL SURVIVAL DATA ANALYSIS

DEWI WULANDARI, Abdurakhman

2014 | Disertasi | PROGRAM STUDI S2 MATEMATIKA

In survival analysis, it’s known a hazard function. It’s a risk or rate of an individual get an event with one conditional, that individual survives until an event occurs. The hazard function may depend on observed risk variables but usually not all variables are known or measurable. This unknown factor of the hazard function is usually termed the individual heterogeneity or frailty. In its simplest form, a frailty is an unobserved random factor that modifies multiplicatively the hazard function of an individual or group or cluster of individuals. In this thesis will be discussed about lognormal frailty model, an extension of Cox regression. Hierarchical likelihood method will be used to estimate the regression coefficients and to find the effect of frailty in the two level survival data.

Kata Kunci : Survival analysis, Cox regression, Hierarchical likelihood, Lognormal frailty model, Two-level survival data