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