Frailty, Advanced Statistics

Assignment Help:

A term usually used for unobserved individual heterogeneity. Such variation is of main concern in the medical statistics particularly in the analysis of the survival times where hazard functions can be strongly influenced by the selection effects operating in the population. There are several possible sources of this heterogeneity, the most apparent of which is that it reflects the biological differences, so that, for instance, some individuals are born with the weaker heart, or a genetic disposition for cancer. A further prospect is that the heterogeneity happens from the occured weaknesses which result from the stresses of life. Failure to take account of this kind of variation might often obscure comparisons between groups, for instance, by measures of relative risk. A simple model which attempts to permit for the variation between individuals is given as follows


1270_fraility.png 


where Z is the quantity specific to an individual, considered as the random variable over the population of individuals, and the base rate is denoted by λ(t) . What is observed in a population for which this type of model holds is not the individual hazard rate but the net result for several individuals with different values of Z.

 


Related Discussions:- Frailty

Disease mapping, The method of displaying the geographical variability of t...

The method of displaying the geographical variability of the disease on maps using different colors, shading, etc. The logic is not new, but the arrival of computers and computer g

Z-tests, Hello! I am currently in graduate school earning a masters in ment...

Hello! I am currently in graduate school earning a masters in mental health counseling. I am in a stats course at current and we are reviewing z-scores. I am a little lost because

Fiducial inference, The problematic and enigmatic theory of an inference in...

The problematic and enigmatic theory of an inference introduced by the Fisher, which extracts a probability distribution for the parameter on the basis of the data without having f

Blinding, Blinding : A procedure used in clinical trials to get rid of the ...

Blinding : A procedure used in clinical trials to get rid of the possible bias which might be introduced if the patient and/or the doctor knew which treatment the patient is receiv

Mosaic displays, Mosaic displays  is the graphical display of the standardi...

Mosaic displays  is the graphical display of the standardized residuals from the fitting a log-linear model to a contingency table in which the colour and outline of the mosaic's '

LASPEYERES QUANTITY INDEX, HOW TO OBTAIN THE LASPEYRES QUANTITY INDEX AND T...

HOW TO OBTAIN THE LASPEYRES QUANTITY INDEX AND THE FORMULA

Staitistics project, I need a statistics project done. How much will it cos...

I need a statistics project done. How much will it cost?

Consolidated standards for reporting trials (consort) , Consolidated Standa...

Consolidated Standards for Reporting Trials (CONSORT) statement : The protocol for reporting the results of the clinical trials. The core contribution of the statement comprises of

Zero sumgame, Zero sumgame is a game played by the number of persons in wh...

Zero sumgame is a game played by the number of persons in which the winner takes all stakes given by the losers so that the algebraic sum of gains at any stage is zero. Number of

Chain-binomial models, Chain-binomial models : Models arising in mathematic...

Chain-binomial models : Models arising in mathematical theory of the quite infectious diseases, which postulate that at any stage in the epidemic there are a certain number of the

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd