Prioritising HTA funding: The benefits and challenges of using value of information in anger
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Transcript of Prioritising HTA funding: The benefits and challenges of using value of information in anger
Prioritising HTA funding: The benefits and challenges of using value
of information in anger
CENTRE FOR HEALTH ECONOMICS
K Claxton, L Ginnelly, MJ Sculpher, Z Philips.
Centre for Health Economics,
University of York, UK
Overview
• Overview of methods• Screening for age-related macular degeneration
– Considered by NCCHTA diagnostic and screening panel
• Manual chest physiotherapy techniques for asthma and chronic obstructive pulmonary disease – Considered by NCCHTA therapeutic procedures panel
• long-term antibiotic treatment for preventing recurrent urinary tract infections (UTI) in children– Considered by Prioritisation Strategy Group (PSG)
An overview of methods
Background• Other methods
– Research as a means changing clinical practice
• Statistical decision theory– Reduction in the costs of decision uncertainty– Value consistent with objective and constraints of service provision
Methods• Constructions of decision analytic model• Probabilistic analysis to characterise decision uncertainty• Value of information analysis
Identifying research priorities
• EVPI– Maximum return to research (decision problem)– Comparing the EVPI to the costs of research– Comparing EVPI across technologies
• Partial EVPI– Maximum return to research (endpoint)– Comparing partial EVPIs– Considering the costs of research
Options• Weekly self screening with Amsler grid• No screen but self referral on decline in visual acuity• No PDT treatment and no screening
Indications• 1st eye neovascular AMD • 20/40 and 20/80 visual acuity • Male and female (age 55-64)• Eligibility of PDT consistent with NICE guidance
Time horizon of 10 yearsNHS Perspective
Screening for age-related macular degeneration (AMD)
Model structure for AMD screening
Angiography
p(Classic|NV AMD)
1- p(Classic|NV AMD)
1-p(Sub|classic)
p(Sub|classic)
No AMD (starting Visual
accuity)
AMD Visual Accuity
(0)
AMD Visual Accuity
(-1)
AMD Visual Accuity
(-2)
AMD Visual Accuity
(-3)
p(T+|no AMD)
Eye examination
Net Benefit of PDT| VA (0)
p(T+|AMD) Eye
examination
p(NV AMD|AMD)=1
p(T+|AMD) Eye
examination
p(NV AMD|AMD)=1
Angiography
p(Classic|NV AMD)
1- p(Classic|NV AMD)
1-p(Sub|classic)
p(Sub|classic) Net Benefit of PDT| VA (-1)
p(T+|AMD) Eye
examination
p(NV AMD|AMD)=1
Angiography
p(Classic|NV AMD)
1- p(Classic|NV AMD)
1-p(Sub|classic)
p(Sub|classic) Net Benefit of PDT| VA (-2)
p(T+|AMD) Eye
examination
p(NV AMD|AMD)=1
Angiography
p(Classic|NV AMD)
1- p(Classic|NV AMD)
1-p(Sub|classic)
p(Sub|classic) Net Benefit of PDT| VA (-3)
p(AMD)
p(VA loss)
p(VA loss)
p(VA loss)
p(refer|VA-3)
p(refer|VA-2)
p(refer|VA-1))
Patient groups• Children treated in the community• Adults treated in the community• Children treated in hospital
Options• Massage therapy• Chiropractic spinal manipulation (CSM)• Physical therapy• No manual therapy
Time horizon of 30-daysNHS perspective
Manual chest physiotherapy techniques for asthma
Patient groups• Adults with stable COPD
Options• Autogenic drainage• Active breathing, • Heat lamp • Chest percussion with drainage• No manual therapy
Time horizon of 30-daysNHS perspective
Manual Chest Physiotherapy Techniques for adults with Chronic Obstructive Pulmonary Disease (COPD)
Structure of the asthma and COPD model
* physical therapy in children with severe asthma only
Baseline FEV
Predicted Quality of Life
Predicted drug cost
proportional change from trials
Intervention FEV
Predicted Quality of Life
Predicted drug cost
Intervention cost
Predicted hospital cost*
Predicted hospital cost*
Patient groups• Infants of 1 year and children age 3• Girls and boys• Recurrent UTI (no abnormalities)• Mild VUR (grade I and II)
Options• Long-term low dose antibiotics (Cochrane review)
(Trimethoprim, Nitrofurantoin, Cotrimoxazole)• Intermittent treatment of UTIs
Time horizon• 3 years of long-term antibiotics and follow-up to end stage renal disease
NHS perspective
long-term antibiotic treatment for preventing recurrent urinary tract infections (UTI) in children
Model Structure for UTI
No UTI
1 UTI
2 UTIs
3 UTIs
4 UTIs
Age atESRD onset
Frequency of recurrent UTIs
Number of pyelonephritic attacks
Progressive renal scaring
End-stage renal disease
TransplantPyelonephritic
attack
Pyelonephritic attack
Pyelonephritic attack
Pyelonephritic attack
Number of attacks
Progressive renal
scaringDevelopment
of ESRD
Dialysis
No UTI
1 UTI
2 UTIs
3 UTIs
4 UTIs
Age atESRD onset
Frequency of recurrent UTIs
Number of pyelonephritic attacks
Progressive renal scaring
End-stage renal disease
TransplantPyelonephritic
attack
Pyelonephritic attack
Pyelonephritic attack
Pyelonephritic attack
Number of attacks
Progressive renal
scaringDevelopment
of ESRD
Dialysis
The evidence
Effectiveness• Existing reviews (variable quality)• Meta analysis, Multiple parameter synthesis• Probabilistic trial based model
Natural history• Epidemiological studies• Pooled trial baselines• Registry studies• Clinical judgement
Quality of life • Published studies• Survey
Costs • Published studies• Published unit costs and dosage (BNF, PSSRU, CIPFA)
Results: cost-effectiveness acceptability curve
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
£0 £10,000 £20,000 £30,000 £40,000 £50,000 £60,000
Threshold for cost-effectiveness
Pro
ba
bili
ty c
ost
-eff
ect
ive
Intermittent
Cotrimoxazole
Nitrofurantoin
Trimethoprim
Frontier
Population EVPI
£0
£500,000
£1,000,000
£1,500,000
£2,000,000
£2,500,000
£3,000,000
£3,500,000
£4,000,000
£0 £10,000 £20,000 £30,000 £40,000 £50,000 £60,000
Cost-effectiveness threshold
Po
pu
laio
n E
VP
I
Results: population EVPI (girls age 3 with no VUR)
Partial EVPI (girls age 3 with no VUR)
£0
£500,000
£1,000,000
£1,500,000
£2,000,000
£2,500,000
Full m
odel
Frequ
ency
of U
TI
Frequ
ency
of p
yelon
ephr
itis
Risk o
f PRS
Utility
of U
TI/pye
lonep
hritis
ESRD
Develo
pmen
t of E
SRD
Conse
quen
ces o
f ESRD
Effect
of L
ong-
term
ant
ibiot
ics
Effect
of co
trim
oxaz
ole
Effect
of n
itrof
uran
atoin
Effect
of tr
imet
hopr
im
Effect
< 6 m
onth
s
Effect
> 6 m
onth
s
Exp
ect
ed
Va
lue
of
Pe
rfe
ct I
nfo
rma
tion
Results: EVPI
Topic Patient Group Population EVPI Partial EVPI
AMD Screening 20/4020/80
£6,950,000£18,220,000
Quality of life with and without PDT
Asthma Physiotherapy
COPD Physiotherapy
Children in CommunityAdults in CommunityChildren in HospitalAdults in Community
£14,500,0000
£1,200,0000
Effect of massage-Effect on LOS and FEV-
UTI prophylaxis Girls 3, no VURGirls 3, VURGirls 1, no VURGirls 1, VURBoys 3, no VURBoys 3, VURBoys 1, no VURBoys 1, VUR
£2,240,000£613,000£690,000£544,000
£41,000£23,000
£267,000£176,000
Effect of prophylaxis on UTI Effect < 6 monthsEffect of: Trimethoprim Cotrimoxazole Nitrofurantoin
Conclusions
Asthma• Children treated in the community
– Massage therapy may be cost-effective– Further research is potentially cost-effective – Effect of massage therapy on FEV1 (no value in effect of CSM)
• Manual physiotherapy for adults treated in the community – Manual therapy not cost effective – Further research not cost-effective
• Children treated in hospital– Physical therapy may be cost-effective– Further research is potentially cost-effective – Effect of physical therapy on hospital length of stay and FEV1
COPD– Manual chest physiotherapy for stable COPD is not cost-effective. – Further research not cost-effective – Inpatient manual chest physiotherapy?
Conclusions
AMD– Screening may be cost-effective – Further research appears to be potentially cost-effective – Evidence about the quality of life with and without PDT
UTI Prophylaxis– Long-term antibiotics are cost-effective for all patient groups
• Which of the antibiotics should be used is uncertain – Primary research maybe required for selected patient groups
• girls age 3 with no VUR– Trials should include head to head comparisons
• Cotrimoxazole and trimethoprim or all three antibiotics– Longer follow-up would be worthwhile
• trials with 6 month follow-up are unlikely to be worthwhile
Feasibility and policy impact
• Feasibility– Completed despite not meeting selection criteria – Analysis conducted and presented within NCCHTA time
lines
• Policy impact– Mixed responses from panel members – Potential (selective) role at PSG – Impact on commissioning decisions
Methods and implementation
• Methods– More complex and resource intensive than anticipated– Comprehensive searching for model parameters– Methods of evidence synthesis– Quality of evidence (bias and exchangeability)– Sensitivity analysis (evidence, model structure)
• Implementation – Communicating complex material– Requires an iterative process– Identifying topics where VoI should be conducted