1 improving quality of life measures by knowledge management methods tamar kakiashvili 1,waldemar w....
TRANSCRIPT
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Improving quality of life measures by knowledge management methods
Tamar Kakiashvili1,Waldemar W. Koczkodaj1,3, Duncan Matheson1,Phyllis Mongomery1, Kalpdrum Passi1, Ryszard Tadeusiewicz2
1 Laurentian University, Sudbury, Ontario, Canada2 AGH University of Science and Technology, Poland 3 the corresponding author: [email protected]
Presenter: Dr. Tengiz Bochorishvili, Academia Podlaska (University of Podlasie), Siedlce, Poland
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Outline
• Medicine and health – measures and instruments
• quality of life and WHOQOL
• consistency-driven pairwise comparisons (CDPC) can be used to improve WHOQOL measure
• Our approach assumes that not all items in an instrument are of equal importance or equally contribute to the total score
• it is expected that computing new weights for each separate item will contribute to the precision of WHOQOL
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Outline
Let us look at WHOQOL web site:
http://www.who.int/substance_abuse/research_tools/whoqolbref/en/
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WHOQOL-BREF labels
Rate QoL• Q1 - Your quality of life (self-assessment)• Q2 - Health satisfaction• Q3 - Pain prevents doing• Q4 - Need medical treatment• Q5 - Enjoy life• Q6 - Life is meaningful• Q7 - Concentrate• Q8 - Safe in your daily life• Q9 - Healthy physical environment• Q10 - Energy for everyday life• Q11 - Accept bodily appearance• Q12 - Money to meet needs
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WHOQOL-BREF variable labels
• Q13 - Information available• Q14 - Opportunity for leisure activities• Q15 - Able to get around• Q16 - Sleep• Q17 - Daily living activities• Q18 - Capacity for work• Q19 - Satisfied with yourself• Q20 - Personal relationships• Q21 - Sex life• Q22 - Friends• Q23 - Conditions of your living place
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• The quality of life definition proposed by World Health Organization (WHO) is important because of its universal acceptability.
• It is a combined effort of 15 research centers who jointly developed a quality of life instrument.
• unfortunately both Canada and Poland are not represented by their research teams but hopefully not for long
WHOQOL
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The pairwise comparisons preliminaries
• Pairwise comparisons method creates a matrix (A) of values (aij) of the i-th object compared with its corresponding (j-th) object (in our case, questionnaire item)
• PC matrix is reciprocal: (aij) =1/(aji) since i to j is (or at least, is expected to be) the reciprocal of j to i.
• A small scale [1/c,c] is used for for comparisons from 5 to 9 (in most practical applications)
• inconsistency analysis is essential since it allows to locate the most inconsistent input
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Inconsistency analysis in brief
The first ever defined: in 1977 by Saaty as a deviation of an eigenvalue of the pairwise comparing matrix.
Eigenvalue is a global characteristic of a matrix
It does not localizes inconsistency
In 1993, a localizing distance based inconsistency definition was proposed by Koczkodaj
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What is inconsistency?
It occurs when we have at least three object to compare. For example taking into consideration their area, we may come to
the following input:
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What is inconsistency?
• The previous picture is fuzzy since our knowledge is anearly always: fuzzy, inexact, incompletem, and inaccurate
• by looking at the above picture, one can even wrongly conclude that if “a” is two times bigger than “b” and “b” is three times bigger than “c” than “a” should be 6, not 5, times bigger than “c”.
• Why? Our input in undisputable! We really do not know if 3 is correct or not (it could be 2.5) or 2 could be 5/3!
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What is inconsistency?
• Our comparisons can be subjective and in the case of QOL, even highly subjective. Often, we cannot be even sure of them. This is a true case of “approximate reasoning” and “incomplete knowledge”
• for a triad, we define inconsistency index as follows:
and it is the minimum distance from the nearest consistent triad
It is not the purpose of this presentation to explain “why” or even “how” the above inconsistency index works but how to use it to improve the QOL measure by using the inconsistency index
1 , 1ij ik kj
ik kj ij
a a aii Min
a a a
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Let us begin with a basic model:
• Explanation: all WHOQOL items have been organized into hierarchical structure
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So let us do it by looking at several screen images:
• This is a part of a model for WHOQOL measure since the full model has not fit into the screen
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screen images:• When we have inconsistency 1/3 or less (but do not even try to
get not zero since it is unrealistic for highly subjective values), we obtain weights:
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In conclusion…
• Many health measures, including the WHOQOL, do not have weights for items
• Applying the pairwise comparisons method to WHOQOLhelps to improve its precision as the preliminary results show (slide or screen image) shows.
• There is very little dispute that pain is more important for QOL than transportation
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In conclusion…
• It is a work-in-progress report
• an initial undertaking is the examination of the feasibility of CDPC method to improve the precision of QOL
• for the final results to be clinically applicable, true assessments must be consulted with the WHOQOL experts and it may not be easy