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<Articles JournalTitle="Journal of Biostatistics and Epidemiology">
  <Article>
    <Journal>
      <PublisherName>Tehran University of Medical Sciences</PublisherName>
      <JournalTitle>Journal of Biostatistics and Epidemiology</JournalTitle>
      <Issn>2383-4196</Issn>
      <Volume>2</Volume>
      <Issue>2</Issue>
      <PubDate PubStatus="epublish">
        <Year>2016</Year>
        <Month>12</Month>
        <Day>26</Day>
      </PubDate>
    </Journal>
    <title locale="en_US">Promotion time cure model with generalized Poisson-Inverse Gaussian Distribution</title>
    <FirstPage>68</FirstPage>
    <LastPage>75</LastPage>
    <Language>EN</Language>
    <AuthorList>
      <Author>
        <FirstName>Mitra</FirstName>
        <LastName>Rahimzadeh</LastName>
        <affiliation locale="en_US">Research Center for Social Determinations of Health, Alborz University of Medical Sciences, Karaj, Iran</affiliation>
      </Author>
      <Author>
        <FirstName>Behrooz</FirstName>
        <LastName>Kavehie</LastName>
        <affiliation locale="en_US">National  Organization   for  Educational  Testing  (NOET)  and  University  of  Social  Welfare  and  Rehabilitation   Science&#xD;
(USWR), Tehran, Iran</affiliation>
      </Author>
    </AuthorList>
    <History>
      <PubDate PubStatus="received">
        <Year>2016</Year>
        <Month>12</Month>
        <Day>25</Day>
      </PubDate>
    </History>
    <abstract locale="en_US">Background &amp; Aim: In the survival data with Long-term survivors the event has not occurred for all the patients despite long-term follow-up, so the survival time for a certain percent is censored at the&#xA0; end&#xA0; of the&#xA0; study.&#xA0; Mixture&#xA0; cure&#xA0; model&#xA0; was&#xA0; introduced&#xA0; by Boag,&#xA0; 1949&#xA0; for&#xA0; reaching&#xA0; a&#xA0; more efficient analysis of this set of data. Because of some disadvantages of this model non-mixture cure model was introduced by Chen, 1999, which became well-known promotion time cure model. This model was based on the latent variable distribution&#xA0; of N. Non mixture cure models has obtained much&#xA0; attention&#xA0; after the introduction&#xA0; of the latent activating&#xA0; Scheme&#xA0; of Cooner,&#xA0; 2007, in recent decades, and diverse distributions have been introduced for latent variable. 
Methods&#xA0; &amp; Materials:&#xA0; In this article,&#xA0; generalized&#xA0; Poisson- inverse&#xA0; Gaussian&#xA0; distribution&#xA0; (GPIG) will be presented for the latent variable of N, and the novel model which is obtained will be utilized in analyzing long-term survival data caused by skin cancer. To estimate the model parameters with Bayesian&#xA0; approach,&#xA0; numerical&#xA0; methods&#xA0; of&#xA0; Monte&#xA0; Carlo&#xA0; Markov&#xA0; chain&#xA0; will&#xA0; be&#xA0; applied.&#xA0; The comparison drawn between the models is on the basis of deviance information criteria (DIC). The model with the least DIC will be selected as the best model. 
Results: The introduced&#xA0; model&#xA0; with GPIG, with deviation&#xA0; criterion&#xA0; of 411.775, had best fitness than&#xA0; Poisson&#xA0; and&#xA0; Poisson-inverse&#xA0; Gaussian&#xA0; distribution&#xA0; with&#xA0; deviation&#xA0; criterion&#xA0; of 426.243&#xA0; and 414.673, respectively.
Conclusion: In the analyzing long-term survivors, to overcome high skewness and over dispersion using distributions that consist of parameters to estimate these statistics may improve the fitness of model. Using distributions which are converted to simpler distributions in special occasions, can be applied as a criterion for comparing other models.</abstract>
    <web_url>https://jbe.tums.ac.ir/index.php/jbe/article/view/80</web_url>
    <pdf_url>https://jbe.tums.ac.ir/index.php/jbe/article/download/80/57</pdf_url>
  </Article>
</Articles>
