The name is absent



22

where i = 0.1,..., n; Di indicates the number of death at time ti∙, Si indicates the
number of survival at time
ti∕, Ni indicates the number of objects at risk at time ti.

The survival function calculated by the K-M estimator is a step function. The
K-M estimator is popular due to the simplicity of its calculation and its ease of
interpretation.

2.3.4 Cox regression model

Cox regression model is also called the Relative Risk model. It is a hazard function
including covariates, denoted as Zi, ...,Z⅛.

A(i∣Zι,...,Zfe) = λo{t)e0^+-+^-

= λ0(t')exp(Z' β)∙,                       (2.16)

Partial likelihood function:

-∣-ι- λp(t)exp{Z β}

L(∕3) =


ɪl Σ Ao(i)eτp(Z'√3)

j∈H(ti)

-∩- exp(Z'β)

ɪɪ ∑ exp{Z'jβ)

j∈B(ti)

ɪɪ exp(Z'β) ,

(2.17)


i=ι [∑e.τp(Z^)]'5fc

fc=l

where δ⅛ is an indicator function. It indicates the number of failures at time к (with
ties).



More intriguing information

1. Effects of a Sport Education Intervention on Students’ Motivational Responses in Physical Education
2. How much do Educational Outcomes Matter in OECD Countries?
3. The name is absent
4. Death as a Fateful Moment? The Reflexive Individual and Scottish Funeral Practices
5. Economic Evaluation of Positron Emission Tomography (PET) in Non Small Cell Lung Cancer (NSCLC), CHERE Working Paper 2007/6
6. The name is absent
7. The name is absent
8. The name is absent
9. EU Preferential Partners in Search of New Policy Strategies for Agriculture: The Case of Citrus Sector in Trinidad and Tobago
10. The name is absent