the comparison of the total alzheimer disease cost of
TRANSCRIPT
Research Proposal
For
The Comparison Of The Total Alzheimer
Disease Cost Of Living Among 22 Countries
Around The World
By
John Wong
MMI 409 Winter 2012
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Introduction: The year 2011 represents the first batch of the post war baby boomers entering
into a “segment of the life span when Alzheimer’s disease (AD) increases exponentially”
(Trojanowski, 2010). Worldwide, 35.6 million people were estimated to have AD in 2010, with
the cost estimated at US$604 billion in the next 20 years (Handels, 2011). In this proposal, we
want to find out if the total AD cost of living (TADCL) is significantly higher in the USA, in
comparison with other countries in the world.
Background: The first case of “presenile dementia” was described by Alois Alzheimer in 1906.
(Mimica, 2010). The development of AD is thought to be caused by disintegration and structural
dysfunction of the tau protein within the neurofibrillary tangles (Bacher, 2010). The disease is
characterized by a deterioration of cognitive behavioral function, with loss of memory, reasoning
and functional capacity (L’opez-Bastidaa, 2009).
Current Treatment: The drug cost for the treatment of AD, represents a good portion of the
total expense incurred by the patient (Handels, 2011). Donepezil, Galantamine, Rivastigmine
and Memantine are approved by the USA Food and Drug Administration (FDA) (Atri, 2011).
Recently, new and expensive intravenous immunoglobulin (IVIG) injections are also used for the
treatment of patients with AD (Bacher, 2010) (Bayry, 2007). For the four FDA approved drugs,
a 10 mg tablet costs as follows: Donepezil $6.6; Galantamine $3.4; Rivastigmine $3.5;
Memantine $2.9 (Suh, 2009). Donepezil is the preferred medication followed by Galantamine
and Rivastigmine (Hollingworth, 2011). The cost per quality adjusted life year (QALY) of
Donepezil is £80,000 (US$128,000); Galantamine £68,000 (US$108,800); Rivastigmine £57,000
(US$91,200); Memantine £37,000 (US$59,200) (Loveman, 2006). Other analysis shows an
incremental cost-effectiveness ratio of Donepezil to be between US$40,000 / QALY (mild AD)
to US$100,000 / QALY (severe AD) (L’opez-Bastidaa, 2009). Furthermore, studies have shown
that benefits may be greatest when treatment is started while patients are still in the mild stages
of AD (Getsios, 2010). Therefore, a patient’s decision to start AD treatment early during the
onset of the disease can be significantly impacted by the cost of the AD treatment.
Problem Statement: Although various studies (Suh, 2009) (Machado, 2011) provide
comprehensive comparisons of AD drug costs across nations , they do not take into account other
expenditures for a total AD cost of living (TADCL) for AD patients. This proposal seeks to
determine if there is significant differences among the TADCL values in various nations, and
whether the TADCL value in the USA is significantly higher than other nations. A by-product
of this analysis is to explore what options exist for a US AD patient to get affordable treatment
outside of the USA. In addition, we want to derive a linear regression equation to predict the
TADCL value. This may allow us to develop strategies to lower the costs, and thereby may help
us to address the un-affordability problem of drugs around the world (Steinbrook, 2007).
Variables: The dependent variable, the total AD cost of living (TADCL), is computed by
multiplying the total cost of care for the patient with the cost of living index, and dividing by the
quality of life index. The higher the cost of living, the higher is the TADCL, whereas a lower
quality of life index means more hardship, which therefore increases the TADCL.
The list of associated variables and their definitions are summarized in Table 1 of Appendix A.
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For the total cost of care for the patient, we will derive the number by the total expenditure paid
for by the AD patient, that includes the annual cost of the AD medication paid by the patient, the
cost of AD medication paid by insurance, the annual cost per caregiver utilized, and the annual
medical checkup expenditures. All costs will be converted by the International Monetary Fund
(IMF) purchasing power parity (PPP) conversion rates (International Monetary Fund, 2010). For
the quality of life index, we will use the quality of life index as suggested by the Economist in
the 2005 World report (The Economist, 2005) (Numeo, 2011). For the cost of living index, we
will use USA, Washington DC as the base location, with a base index value of 100. The cost of
living index for various locations will be calculated by the COLI calculator from Xpatulator.com
(Xpatulator, 2012).
Formula: TADCL = (Cost of the AD medication paid by the AD patient + Cost of the AD
medication paid by insurance + the annual cost per caregiver utilized + annual medical checkup
expenditures) x Cost of Living Index / Quality of Life index [Formula 1.1].
Constraints: Since countries have different health coverage rules, we cannot take into account
every single cost and reimbursement detail from every country. Therefore, the simplification of
the total cost of care calculation represents a potential weakness of this research study.
Method: For the research, we will work with local Alzheimer Associations in each country.
Participants for the research will be randomly picked from the associations’ registries.
Volunteers will call the potential candidates to obtain the values for the list of variables listed in
Appendix A Table 1. In order to prevent over counting the TADCL due to combination drug
therapies, we will limit our samples to AD patients who are taking one type of medication only.
The volunteers will continue to call until viable data are collected from 200 patients. Collected
information will be entered via secure SSL into an encrypted central database online. To ensure
HIPAA compliance, no identifiable patient information, such as name, id, etc., will be recorded.
The TADCL values will be calculated and presented in a matrix of n=200 subjects by k=22
countries (Appendix A Table 2).
The research will be conducted in 22 countries (Argentina, Australia, Brazil, the Dominican
Republic, France, Hong Kong, India, Japan, Macedonia, Mexico, New Zealand, Nigeria, the
Philippines, Portugal, Serbia, South Korea, Switzerland, Taiwan, Thailand, Uganda, the U.K.,
and the U.S.A.), similar to the ones used in the Suh study for logistic feasibility purpose.
Hypotheses: The hypotheses of the research are as follow:
H0: There is no significant differences in the TADCL among the various countries (i.e.
µ(1) = µ(2) = … = µ(k), where k = number of countries) versus
H1: There is significant differences in the TADCL among the various countries (i.e. µ(1)
≠µ(2) ≠… ≠ µ(k), where k = number of countries).
H2: The TADCL is significantly higher in the USA versus most other countries. (e.g.
µ(USA) > µ(Mexico))
Measures: For the analysis, we will group the 4400 subjects by the AD drugs used. The analysis
will be run using SPSS version 19 (IBM). Since we are comparing more than two sample
means, we will use ANOVA for the analysis (Analyze -> Compare Means -> One Way
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ANOVA). Then, we will use the Tukey procedure to perform post hoc pairwise analysis on the
countries. For the correlations among the various variables, we will use SPSS to perform a
multi-variable linear regression analysis (Analyze -> Regression -> Linear). The linear
regression analysis will tell us the contribution of each factor to the TADCL value.
Analysis: Since we have not conducted the experiment, we will hypothesize an analysis of the
results and the outputs from the experiment:
1) First, we can produce a box plot (simulated in Appendix B Graph 1) from the raw data
collected (Appendix A Table 1). In the simulated graph, we can see that the USA has a
higher median TADCL in comparison with other countries, while Japan, the UK, and
Hong Kong are also high. One would reason that these countries have higher AD drug
costs, and also higher costs of living, which contributes to the higher TADCL.
2) From the linear regression analysis, the R-squared value of 0.486 means that the
regression does a good job of modeling the TADCL, as nearly half of the variation in
TADCL is explained by the model (simulated in Appendix B Table 1). Among the
various variables, gender and quality of life index do not contribute to the model (p value
> 0.05) (simulated in Appendix B Table 2). Furthermore, from the standardized
coefficient column, we can see that $ drug paid by patient and $ medical procedures
contribute more to the model because they have larger absolute standardized coefficients.
3) From the calculated TADCL values (Appendix A Table 2), we can run an ANOVA
analysis (simulated in Appendix B Table 3): With the p value at 0.003, we can reject the
null hypothesis and conclude that there is a significant difference in the TADCL values
for Donepezil across the various countries. The same analysis can be performed for the
other AD drugs.
4) From the post hoc pairwise analysis (simulated in Appendix B Table 4), the simulated
result shows that TADCL level in Group 1 (USA) is significantly different than the
TADCL levels in Group 2, 3, 4, 5, and 20, as the p values are less than 0.05. In addition,
from the mean differences, we can see that the TADCL for the USA is higher than the
TADCLs for Group 2, 3, 4, 5, and 20. On the other hand, there are no significant
differences between the TADCL in the USA, and the TADCLs in Group 6, 7, 21, 22.
Summary: AD is the most common form of dementia among elderly populations and is the
fourth leading cause of death in the developed world (Bacher, 2010). It is estimated that 65
million people worldwide will suffer from some form of dementia by 2030 (Mimica, 2010). As
mentioned in the introduction, the total cost can amount to $604 billion as more baby boomers
reach 65 years old. The purpose of this research was to explore the differences among the Total
Alzheimer Disease Cost of Living in the 22 nations selected. More importantly, we wanted to
find out which countries’ TADCL values are most significantly different from that of the USA.
The result can be used as a possible guidance to patients for potential AD treatments outside of
the USA. And last, from the linear regression equation, we can determine which factors
contributed most to the TADCL value. This may allow us to devise strategies against those
factors to minimize the TADCL for better treatment and affordability of AD drugs around the
world.
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Appendix A: Data
Table 1: Variables Definitions
Variable Type Values Data Source
Age Scale Interview with Patient
Gender Nominal 0 = Male, 1 =
Female
Interview
Severity of AD Ordinal 1 to 5 (Mild to
Severe)
Interview
AD Drug Taken Nominal 1 = Donepezil
2 = Galantamine
3 = Rivastigmine
4 = Memantine
5 = IViG
6 = Other
Interview
Dosage per day Interval e.g. 5 mg, 10 mg,
etc.
Interview
Health Insurance
coverage
Nominal 0 = No, 1 = Yes Interview
$ paid by patient
per year
Scale Interview
$ paid by health
insurance
Scale Interview
$ per caregiver
per year
Scale Interview
$ medical
expenditures per
year (check up,
treatment)
Scale Interview
Cost of Living
Index
Scale Calculated from
Xpatulator.com, using
Washington, DC, USA as the
base location with index value
of 100
Quality of Life
index
Scale Obtained from
nationranking.wordpress.com
PPP Conversion
Rate
Scale Obtained from IMF.gov
Countries Nominal Listed from 1 to n
alphabetically
Interview
TADCL Scale Computed using formula 1.1*
* TADCL = (Annual cost of the AD medication paid by the AD patient + Annual cost of the AD
medication paid by insurance + the annual cost per caregiver utilized + annual medical checkup
expenditures) x Cost of Living Index / Quality of Life index. All costs adjusted by the PPP
conversion rate. [Formula 1.1]
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Table 2: Calculated TADCL table for ANOVA Analysis
US
A
Arg
enti
na
Au
stra
lia
Do
min
ica
n R
ep
ub
lic
Fra
nce
Ho
ng
Ko
ng
Ind
ia
Ja
pa
n
Ma
ced
on
ia
Mex
ico
New
Zea
lan
d
Nig
eria
Ph
ilip
pin
es
Po
rtu
ga
l
Ser
bia
So
uth
Ko
rea
Sw
itzer
lan
d
Ta
iwa
n
Th
ail
an
d
Ug
an
da
UK
TADCL
1.A
TADCL
1.B
… … … … … … … … … … … … … … … … … … TADCL
1.V
TADCL
2.A
TADCL
2.B
… … … … … … … … … … … … … … … … … … TADCL
2.V
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
… … … … … … … … … … … … … … … … … … … … …
TADCL
200.A
TADCL
200.B
… … … … … … … … … … … … … … … … … … TADCL
200.V
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Appendix B: Hypothesized Analysis
Graph 1: Simulated Box Plot
Appendix B: Hypothesized Analysis
Table 1: Simulated Linear Regression Analysis Model Summary
Model Summary
Model R R Square Adjusted R Square Std. Error of the Estimate
1 .697a .486 .449 .98960
a. Predictors: (Constant), Age, Gender, Severity of AD, AD drug taken, $ drug paid by patient, $ paid
by insurance, $ caregiver cost, $ medical procedures, Quality of Life index, insurance coverage,
Cost of living index
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Table 2: Simulated Linear Regression Coefficients
Coefficientsa
Model
Unstandardized
Coefficients
Standardized
Coefficients
t Sig.
Correlations
Collinearity
Statistics
B
Std.
Error Beta
Zero-
order Partial Part Tolerance VIF
1 (Constant) -3.017 2.741 -1.101 .273
Age .883 .331 .293 2.670 .008 .274 .219 .161 .304 3.293
Gender -.046 .013 -.002 -3.596 .611 -.552 -.290 -.217 .187 5.337
Severity of AD .356 .190 .281 1.871 .063 -.135 .156 .113 .162 6.159
AD Drug Taken -.002 .004 -.092 -.509 .021 -.389 -.043 -.031 .112 8.896
$ drug paid by patient .042 .023 .541 1.785 .006 .292 .149 .108 .200 4.997
$ drug paid by insurance .042 .023 .541 1.785 .006 .292 .149 .108 .200 4.997
$ caregiver cost -.028 .042 -.073 -.676 .070 .037 -.057 -.041 .313 3.193
$ medical procedures .015 .014 .448 1.032 .004 .215 .087 .062 .178 5.605
Quality of Life Index .156 .350 .075 .447 .655 -.041 .038 .027 .131 7.644
Insurance Coverage -.057 .047 -.167 -1.203 .031 -.016 -.101 -.073 .189 5.303
Cost of Living Index .081 .040 .262 2.023 .005 .121 .168 .122 .217 4.604
a. Dependent Variable: TADCL
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Table 3: Simulated ANOVA Analysis on TADCL for Donepezil
ANOVA
TADCL For Donepezil
Sum of
Squares df
Mean
Square F Sig.
Between
Groups
198.009 21 9.429 6.729 .003
Within Groups 582.816 416 1.401
Total 780.825 439
Table 4: Simulated Tukey Post Hoc Analysis
Multiple Comparisons
TADCL for Donepezil
Tukey HSD
(I)
Group (J) Group
Mean
Difference
(I-J)
Std.
Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
1 2 2.08333* .68341 .030 -3.9962 -.1705
3 2.25000* .68341 .018 -4.1628 -.3372
4 2.89167* .68341 .002 -4.8045 -.9788
5 2.08333* .68341 .030 .1705 3.9962
6 -.16667 .68341 .995 -2.0795 1.7462
7 -.80833 .68341 .644 -2.7212 1.1045
… 2.25000* .68341 .018 .3372 4.1628
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… .16667 .68341 .995 -1.7462 2.0795
… -.64167 .68341 .785 -2.5545 1.2712
20 2.89167* .68341 .002 .9788 4.8045
21 .80833 .68341 .644 -1.1045 2.7212
22 .64167 .68341 .785 -1.2712 2.5545
*. The mean difference is significant at the 0.05 level.
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