Transcript Document

Behnam Sharif
Star team trainee
Webinar APRIL 29-2011
Outline
 Background: Cost of Osteoarthritis(OA)
 Direct cost:
 Results of the OA direct cost study
 Implementing in (POHEM)
 Indirect cost:
 Components of indirect cost in OA
 Issues of Implementing in (POHEM)
 Future projects of indirect cost of OA
Background
 Arthritis is a leading cause of chronic pain and
mobility limitation .
 Osteoarthritis (OA) accounts for approximately
50-65% of arthritic diseases (most common form
of arthritis )
 Total cost of OA, including direct and indirect
cost, accounts for up to 0.2–0.8% of the gross
domestic product of western nations (1)
Background (cont’d)
 Authors in (1) report that by the year 2026, over 6
million Canadians will suffer from arthritis (almost
two fold increase compare to 2000).
 Arthritis cost is substantial ( in comparison to other
chronic diseases) and will be higher in future.
 ADVANTAGES of using POHEM in cost projection studies:
 Cost of illness (COI) studies project the future burden of OA by
only considering the trend in population aging.
 However, there is a large gap in projection studies of OA, which is
due to ignoring the trend of obesity prevalence, an epidemic in
western countries
Cost of OA
 Direct cost: in-patient, out-patient, medication, out-
of-pocket cost, and side effects of medications.
Indirect cost categories are
 Indirect cost : Absenteeism, Presenteeism, Informal
caregiver’s productivity loss, work transition
productivity loss.
Indirect cost
 Work transitions (early retirement, changing jobs,
reduced hours, etc.)
 Work transitions have been discussed as being negligible in OA while
early retirement discussed to be significant in OA patients
 Absenteeism: OA-related productivity loss because
of missed work days
 Presenteeism: , OA-related at-work productivity loss
 On average 56% (35%-77%) of total cost of OA including medical,
pharmacy, absenteeism and presenteeism is attributed only to
presenteeism (4)
 Informal caregiver cost: Unlike RA, it constitute a significant portion of
the indirect cost of OA (40% reported in (1).
Ratio of direct and indirect cost
in OA
 A cost study in Ontario in 2004 reported an average
cost of 12,200$ per year for OA patients, with 80%
accounted for indirect cost. (4)
 Yelin and Callahan(7) estimates the costs of
productivity losses to be $49.6 billion, 3.26 times
greater than the total medical costs of 15.2 billion for
OA patients in $US, year 2000
 Gabriel and colleagues(8), found average indirect cost
to be $824 (1992 US dollars), i.e., 31% of the $2654 =
direct medical charges for sample of patients with OA
Problems in COI studies
 In a recent review, Lee et al.(4) mentioned the existence of huge
variation among the cost estimates of OA in different studies. In (5):
Observed an up to 40-fold variation in cost of Illness (COI) estimates
for the same disorder.
 Major problems in COI studies(5): Using cross-sectional data and lack
of controls, one data source and ignoring comorbidities and
heterogeneity of patients Advantages of using microsimulation
for cost projection
 Human capital vs. friction-based approach : Recent studies
agree that :
 indirect cost has been reported to be 4 times higher than direct cost
in all types of arthritis
 indirect cost of OA is 25-50% of its direct cost from a societal
perspective
Cost in POHEM (Cont’d)
 POHEM-cancer models (Lung, Breast and colorectal)
have DIRECT COST only
 For cost-effectiveness studies (and technology
assessment models) both direct and indirect cost are
needed.
Background-direct cost
 Previous work has been conducted either on a macro
level (e.g. cost of illness), comparison between types of
arthritis (e.g. OA vs RA), or on cost of specific events
(e.g. cost effectiveness of TJAs)
 Little work has been conducted on OA specifically at a
patient level, examining costs over time
Direct cost study of OA
 Study done by Mushfiqur, Nick Bansback et al. in
2008.
 Data source: BC Admin data, year 2003
 Methods:
 Population Data BC: hospital admissions as well as office
visits covered .
 PharmaNet Data: A stratified random sample of 100,000
individuals --stratified according to different OA stages(and
Non-OA)
 St.Paul’s hospital cost model: hip and knee replacements
 Out of Pocket cost: NPHS (Eric’s model)
Direct cost study of OA (Cont’d)
 States: : With the exception of the hip and knee
replacement analysis, patient records were categorized by
age group (0-49, 50-59, 60-69, 70-79, 80-89, 90+), gender,
stage (no OA, OA diagnosis, Surgeon visit, primary
hip/knee replacement, revised hip/knee replacement) and
time in stage (0-1.9 years, 2-4.9 years, 5 years+).
 Average person years and weighted person years and
cost were calculated and summed for each state.
 Total cost divided by weighted person years was then
used to calculate per person annual costs.
Direct cost study of OA (results)
NOOA
oa0.0 oa2.0 oa5.0 os0.0 os2.0 os5.0 prim0 prim2 prim5 revi0. revi2. revi5.
-1.9y -4.9y +y
-1.9y -4.9y +y
.0+y 00+y
.0.001.9y 4.9y
1.9y 4.9y
Fema
le
00-49
$24
$661
$166
$168
$778
$213
$8,810
$690
$291
$10,698
$886
$505
$24
$45
$842
$258
$277
$1,013
$313
$8,885
$810
$307
$10,807
$727
$429
$45
$32
$812
$282
$301
$1,114
$317
$8,920
$675
$327
$10,744
$609
$430
$32
$36
$788
$307
$296
$959
$305
$8,925
$858
$333
$10,685
$641
$338
$36
$47
$523
$192
$242
$593
$246
$8,823
$655
$250
$10,666
$519
$165
$47
$52
$259
$139
$162
$503
$216
$8,780
$417
$240
$10,637
$412
$231
$52
$39
$648
$224
$241
$827
$268
$8,857
$684
$292
$10,706
$632
$350
$39
$18
$758
$158
$198
$761
$141
$8,763
$856
$297
$10,837
$1,264
$579
$18
$36
$783
$205
$293
$882
$243
$8,854
$653
$251
$10,680
$601
$528
$36
$33
$750
$216
$306
$933
$218
$8,837
$642
$237
$10,673
$809
$395
$33
$29
$782
$232
$258
$892
$248
$8,874
$761
$238
$10,651
$598
$339
$29
$27
$408
$145
$166
$507
$200
$8,770
$596
$145
$10,595
$418
$198
$27
$33
$233
$99
$133
$451
$142
$8,729
$208
$112
$10,559
$324
$57
$33
$29
$619
$176
$226
$737
$199
$8,805
$619
$214
$10,666
$669
$349
$29
50-59
60-69
70-79
80-89
90+
Mean
Male
00-49
50-59
60-69
70-79
80-89
90+
Mean
Outline
 Background: Cost of Osteoarthritis(OA)
 Direct cost:
 Results of the OA direct cost study
 Implementing in (POHEM)
 Indirect cost:
 Components of indirect cost in OA
 Issues of Implementing in (POHEM)
 Future projects of indirect cost of OA
POHEM (Cost modules included)
Slide form Bill’s presentation (October-2009)Modified for inclusion of cost (by Bsh)
Starting Population: Canadian Community Health Survey 2001 (CCHS)
cross-sectional representation of the Canadian population aged 18+
2001
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
VARIABLE
age
sex
province
health region
immigration status
education level
income quartile
body mass index
smoking status
diabetic status
HUI
SROA
VALUE
44
male
Ontario
York
non-immigrant
post-secondary
Q4 (richest)
Survey sample weight
100.32
32.2 kg/m2 (obese)
smoker
non-diabetic
0.96
Yes
OA Prevalence in
2001?
Every year on
birthday
• Apply OA prevalence
• update risk
rates (conditional on
SROA, HUI, BMI, age, factor profile
sex)
 yes
• Assign OA status
OS1
o Assign direct cost
(conditional on sex,
age group, OA-status,
OA-cycle)
 OADirect_cost
• Assign survival time
to next OA event(s)
 3.7 years to OS2
 5.1 years to surgery
•evaluate
hazard of dying
 +48.9 years
POHEM example
Starting Population: Canadian Community Health Survey 2001 (CCHS)
cross-sectional representation of the Canadian population aged 18+
2001
2002
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
age
sex
province
health region
immigration status
education level
income quartile
body mass index
smoking status
diabetic status
HUI
OA status (OS1)
CostOA
Every year on
birthday
• update risk factor
profile
• evaluate hazard
of developing
disease
• evaluate hazard
of dying
POHEM
Starting Population: Canadian Community Health Survey 2001 (CCHS)
cross-sectional representation of the Canadian population aged 18+
2001
2002
2003
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
……..
…
……..
……..
Death
• >100,000 records on CCHS representing ~30 million Canadians
• 3 hours on a PC- 12 GHz RAM- Cpu=i7 Intel-980
Indirect cost?
Starting Population: Canadian Community Health Survey 2001 (CCHS)
cross-sectional representation of the Canadian population aged 18+
VARIABLE
2001 age
sex
……..
……..
province
……..
……..
health region
……..
immigration status
……..
……..
education level
……..
……..
income quartile
……..
……..
Income categories
body mass index
smoking status
diabetic status
HUI
SROA,
New
variables
form
CCHS
Survey sample weight
Job Status
Job Categories
VALUE
44
male
Ontario
York
non-immigrant
post-secondary
OA Prevalence in
2001?
Q4 (richest)
• Assign OA status
disease
32.2 kg/m2 (obese)
OS1
smoker
non-diabetic
0.96
Yes,
•Assign direct cost
(conditional on sex,
age group, OA-status,
OA-cycle)
no new
diseases in 2001
100.32
 OADirect_cost
20,000$-30,000$
Employed
Sales
Every year on
birthday
• Apply OA prevalence
• update risk
rates (conditional on
SROA, HUI, BMI, age, factor profile
sex)
• evaluate hazard
of developing
 yes
• Assign survival time
to next OA event(s)
 3.7 years to OS2
 5.1 years to surgery
• evaluate
hazard of dying
 8.9 years
Implementing direct cost in POHEM
Step 1. Defining new parameter  OADirect-cost
 Four dimensions -based on Direct cost final results :



(Age categories, Sex, OA cycle, OA state)
OAcost[sex][OA_age][OA_stage][OA_cycle]
Code: put the parameter in “base(OA).dat” file; Declare
it in “OA.mpp”
Step 2. Define a function to update the direct Cost
variable (the same way as done for other risk factors in the patient(ACTOR)
profile)
Step 3. Define a Table for output in “TAB.OA.mpp” to
output the: (1) Total direct cost of OA ( sex-specific),
(2) Average direct cost per OA patient (sex-specific),
etc.
Outline
 Background: Cost of Osteoarthritis(OA)
 Direct cost:
 Results of the OA direct cost study
 Implementing in (POHEM)
 Indirect cost:
 Components of indirect cost in OA
 Issues of Implementing in (POHEM)
 Future projects of indirect cost of OA
Indirect cost- future projects
Objective of Indirect cost projects:
 Estimating the Indirect Costs of Osteoarthritis
using POHEM
 This will include: Early retirement, Absenteeism and
presenteeism due to OA.
 Although numerous studies estimated cost of OA, this the
first study ( to our knowledge) that uses an individual-level
simulation model (POHEM-OA) to estimate and project
the cost burden of OA.
Indirect cost– future projects (Cont’d)
 Job status (Employed or not) are needed in all of the
indirect cost projects.
 Goal is to provide same type of table as in Direct cost for
absenteeism and presenteeism.
 For Early retirement, we will use an event-based approach
(Using Relative Risks of leaving the work force based on
sex, age and OA status) suing NPHS and PALS
 Absenteeism and presenteeism using MoH data
 Informal caregiver cost  Literature
Early retirement project
Methods
• Retrospective cohort
• NPHS : The NPHS longitudinal sample includes 17,276 persons from all
•
•
•
•
•
ages in 1994/1995 and these same persons will be interviewed every two
years.
We Used 7 available cycle of the National Population Health Survey
Data (NPHS) from (1994/1995) to (2006/2007).
In 2000, detailed question on Arthritis including: Surgery, type of
arthritis, medication, etc.
We used questions on arthritis type (Osteoarthritis, Rheumatoid
arthritis and other types), time of physician diagnosis, surgery status
for definition of OA(cycle, state) as our main explanatory variable.
Sample both non-OA and OA matching on Age and sex.
Performing a conditional logistic model to estimate the Relative risks
Absenteeism
 MoH data on 2250 OA patients,
 Questions on :Being absent last year or not? How many
days?
 Two stage model:
 Stage1- Estimating the differential probability of
absenteeism for OA cases. Explanatory variable : OA
stages, cycle, sex, age categories, job type, etc.
 Stage2- Estimating number of days for those who had
reported of being absent last year due to OA.
 Result of same table as in direct cost . One for probability for missing
work, one for number of days.
 Implemented in POHEM, based on the income calculated daily.
MoH Data- Absenteeism model
 Outcome: probability fo being absent (Stage 1),
Number of days absent (stage 2)
 Population: Only OA patients.
 Covariates: age categories, sex, time since diagnosis of
OA (<5 years, 5-9, 10-19 and >20), HUI and education
level
 Job categories: 16 groups of job-types (Accounting,
construction, management, etc)
 Comorbidities: hypertension, hyperlipidemia, anxiety disorders,
diabetes, or asthma
Discussion
 Individual-level cost estimates using microsimulation
model are different from Cost of illness studies. Since, the
final goal is to implement (unit) cost estimates into
microsimulation model (POHEM-OA)
 Two types of model for individual-level cost estimation:
 State-based: Providing a table of different stages of OA and cost
estimates for each cell of the table. This is done in direct cost ,
absenteeism and presenteeism projects.
 Event-based (Such as Early retirement model): we are able to include
the individual-level probability of early retirement into the simulation
model as an event based on an individual state (age, sex, type of job
and other covariates).
References
 (1) S. Gupta, G. A. Hawker4, A. Laporte, R. Croxford and P. C. Coyte. The
economic burden of disabling hip and knee osteoarthritis (OA) from the
perspective of individuals living with this condition. Rheumatology 2005;
44:1531–1537.
 (2)Systematic review of the long-term effects and economic consequences of
treatments for obesity and implications for health improvement, Health
Technology Assessment 2004; Vol. 8: No. 21 A Avenell, J Broom, TJ Brown, A
Poobalan, L Aucott, SC Stearns, WCS Smith, RT Jung, MK Campbell and AM
Grant
 (3). NHS Centre for Reviews and Dissemination. A systematic review of the
interventions for the prevention and treatment of obesity, and the
maintenance of weight loss. NHS CRD Report
No. 10. York: University of York; 1997.
 (4). CMAJ • April 10, 2007 • 176(8), Synopsis of the 2006 Canadian clinical
practice guidelines, on the management and prevention of obesity in adults
and children, David C.W. Lau, for the Obesity Canada Clinical Practice
Guidelines Steering Committee and Expert Panel
Questions
?