Transplantation is the only viable therapy for end-stage liver
diseases (ESLD) such as hepatitis B. In the United States,
patients with ESLD are placed on a waiting list. When organs
become available, they are offered to the patients on this waiting
list. This dissertation focuses on the decision problem faced by
these patients: which offer to accept and which to refuse? This
decision depends on two major components: the patient's current
and future health, as well as the current and future prospect for
organ offers. A recent analysis of liver transplant data indicates
that 60\% of all livers offered to patients for transplantation
are refused.
This problem is formulated as a discrete-time Markov decision
process (MDP). This dissertation analyzes three MDP models, each
representing a different situation. The Living-Donor-Only Model
considers the problem of optimal timing of living-donor liver
transplantation, which is accomplished by removing an entire lobe
of a living donor's liver and implanting it into the recipient.
The Cadaveric-Donor-Only Model considers the problem of
accepting/refusing a cadaveric liver offer when the patient is on
the waiting list but has no available living donor. In this model,
the effect of the waiting list is incorporated into the decision
model implicitly through the probability of being offered a liver.
The Living-and-Cadaveric-Donor Model is the most general model.
This model combines the first two models, in that the patient is
both listed on the waiting list and also has an available living
donor. The patient can accept the cadaveric liver offer, decline
the cadaveric liver offer and use the living-donor liver, or
decline both and continue to wait.
This dissertation derives structural properties of all three
models, including several sets of conditions that ensure the
existence of intuitively structured policies such as control-limit
policies. The computational experiments use clinical data, and
show that the optimal policy is typically of control-limit type.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-07262004-183027 |
| Date | 13 September 2004 |
| Creators | Alagoz, Oguzhan |
| Contributors | Lisa Maillart, Andrew Schaefer, Cindy Bryce, Matthew Bailey, Mainak Mazumdar, Mark Roberts |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-07262004-183027/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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