Cessation in Pregnancy Incentives Trial (CPIT): effectiveness & cost

effectiveness Linda Bauld & Kathleen Boyd

on behalf of The CPIT Research Team

Jun-14

Outline

• CPIT Trial– Background & context– Design– Main Results

• Economic Evaluation– Within-trial analysis– Lifetime analysis– Results

• Conclusions

Background

• 70% women have babies - pregnancy ideal opportunity to help

• > 20% of pregnant women smoke in Scotland - < 1 in 20 quit

• Protects from miscarriage, stillbirth, pre-term birth & low birth weight

• Lifelong benefits include reduced incidence asthma, ADD & adult CVD

• Children of smokers often smoke themselves

• Extra pregnancy (£100-£700) & first year health services costs (£150 - £300) per smoker

Why Financial Incentives?

• Used in other areas of public health with some success

• Evidence that increase engagement, retention & cessation

• Best evidence of efficacy for incentives in pregnancy

• Cochrane review - financial incentives more effective than other intervention strategies

• Growing evidence of ‘real world’ effectiveness from incentives schemes across UK

• NICE Recommendation for UK trial of incentives

All women in Greater Glasgow & Clyde HB area who smoked offered enrolment over 15 months

612 pregnant smokers enrolled

306 normal care

Usual NHS support

9% quitters

306 incentives

Up to £400 contingent on setting quit date & abstinence @ 4, 12 & 34-38 weeks PLUS normal NHS support

23% quitters

Intervention &

control

Primary O/CCessation in late

pregnancy (saliva cotinine validated )

Allocation

Assessment

Trial Design

Main Trial ResultsPrimary Outcome • 14% absolute reduction in quit rates late pregnancy (9% vs 23%)• RR smoking at end of pregnancy 0.85 [95% CI 0.79-0.91, p<0.0001] • Results unaffected after control for nicotine dependence• Around 20% may have ‘gamed’ cotinine assay• ‘True’ quit rate perhaps more modest 18% vs 7%

Secondary Outcomes• 81% intervention vs 78% control engaged with SPS • Improved cessation rate at 4 weeks with incentives (43% vs 21%)• SR abstinence postnatally (>=12 months after quit date) did not

show increase in relapse rate in incentives group• No difference in birthweight, stillbirth, miscarriage, or premature

births between groups

Qualitative & Health Economic Results• Qualitative analysis indicates: - accounts of trial participation positive

- home based monitoring visits acceptable - incentives generally acceptable to women & HCPs - women & HCPs thought ‘gaming’ was possible

• Health economic analysis indicates: - short term cost effectiveness £1127 per additional quitter - lifetime analysis incremental cost of £482 per QALY gained - uncertainty around sustained quit rates postnatally & results sensitive to this

Voucher Spend

Ernest Jones SemichemShoezone

Spend

£72£4,485£4,872£3,915

£1,184£1,183

£202£462

£51,363£461

£3,891£313

£25

The Factory Shop

Retailer

Wilkinson

Superdrug

River Island

Total

TJ HughesToys R Us

£2,666

Peacocks £114Poundstretcher £1,360

New LookOfficers Club

MatalanMothercare

Retailer Spend

BHS £755Argos £11,053

H Samuel £149

Boots £3,312Comet £50Debenhams £1,842DW Fitness £139Early Learning Centre £153

JJB Sports £170

Halfords £248HMV £418Homebase £287House Of Fraser £40Iceland £8,626

Economic Evaluation• We know that smoking cessation is cost-effective• Could Financial Incentives offer value for money

compared to other cessation support?• Financial Incentives+ usual care V’s usual care• Incremental cost-effectiveness ratio (ICER)

• Within-trial analysis: Incremental cost per quitter• Lifetime analysis: Incremental cost per QALY

QALY per £20,000EffectEffect

CostCost:ICER

BA

BA

Methods – Within trial • Estimate Resource Use

– NRT– Cessation support

• Face to face, phone calls – Financial Incentive vouchers

• Combine with unit costs– PSSRU, BNF– NHS Reference Costs

• Estimate Quit Rate– 34-38 week cotinine validated

• Incremental cost, Incremental quit

Pregnant woman who smokes

TreatmentFinancial incentive

+ usual care

Quit 34-38 weeks

Not quit

Within trial analysis - trial duration

ControlUsual care

outcomes

£ cost

£ cost

Quit 34-38 weeks

Not quit

Decision Tree pathway

Lifetime analysis - Markov Model

£ cost low birth weight baby

Utility

Model Specifics• 2 Cohorts• Mean age 28 yrs (CPIT trial)• Time horizon 75 years• Annual cycles• Discount rate 3.5%

Sensitivity Analysis• Probabilistic analysis• 6 scenario analyses

• Postnatal relapse

Successful quit 34-38 weeks

No postnatal relapse 3 months

No quit 34-38 weeks

3 months postnatal relapse

Risk relapse

up to 8 yrs

Background

mortality rate

Utility

£ cost (scenario analysis)

Smoking related

mortality rate

Base-case results

  Within trial outcomesLifetime model outcomes (discounted 3.5%)

InterventionWithin trial Mean Cost

Prob quit 34-38 wks

Lifetime Mean cost

Lifetime QALY gained

Control £85.38 0.086 £1,265 19.10

Incentives £242.75 0.227 £1,282 19.14

Difference £157.36 0.14 -£17.21 0.036

(95% CI) (£155, £162) (0.08, 0.19) (-£93, £107) (-0.058, 0.145)

ICER  £1127 per quitter £482 per QALY gained

Cost-effectiveness plane: Incentives vs usual care

1000 incremental cost & QALY results from PSA

Considerable uncertainty!Driven by uncertainty in postnatal relapse

-assumed 60% Incentives, 30% Usual care

-0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25

-£250

-£200

-£150

-£100

-£50

£0

£50

£100

£150

£200

Incremental QALYs

Incr

emen

tal C

osts

Conclusions

• Financial incentives may double the rates of abstinence from smoking at the end of pregnancy (8.6% to 22.5%) when added to existing cessation services

• Financial Incentives are likely to be highly cost-effective & well below the NICE threshold of £20,000/QALY

• Uncertainty remains regarding post-natal relapse– When we use self-reported postnatal estimates at 3 months Financial

incentives are cost saving and improve QALYs!

• Larger trial now required to demonstrate if this can work in other areas

Acknowledgements

• This study was funded by the Chief Scientist’s Office of the Scottish Government, NHS Greater Glasgow and Clyde, the Glasgow Centre for Population Health and the Yorkhill Children’s Foundation

• Research Team members included:

• Prof David Tappin, Prof Linda Bauld, Ms Lesley Sinclair, Dr Kathleen Boyd, Prof Andy Briggs, Dr Alex McConnachie, Mr David Purves, Dr Andrew Radley, Prof Tim Coleman, Mrs Margaret McFadden, Mrs Sue Stevenson and colleagues

• Particular thanks to:• NHS GG&C Smokefree Pregnancy

Service staff, Prof Carol Tannahill, Dr Linda de Caesteker, Mrs Brenda Friel, and Mrs Janet Ferguson

Thank you

Linda.Bauld@stir.ac.ukKathleen.Boyd@glasgow.ac.uk

Additional Info – Scenario analyses

1 Self- reported postnatal relapse Control £1,245 19.08

Incentives 33%, Control 54% Incentives £1,267 19.21 £21 0.13 £164 0.99

(-£87, £101) (0.018, 0.228)

2 Incentive arm assume higher Control £1,257 19.10

Postnatal Risk Relapse Incentives £1,277 19.09 £20 - 0.017 Usual Care 0.30

(mean 80%, se 0.18) (-£101, £99) (-0.092, 0.15) Dominates3 Include cost for Control £25,397 19.10

smoking related disease Incentives £24,820 19.14 - £577 0.039 Incentives 0.73(£32,658, se £6532) (-£2382, £821) (-0.05, 0.15) Dominates

4 Discount rate 0% Control £1,254 40.02

Incentives £1,274 40.14 £20 0.117 £167 0.75

(-£90, £100) (-0.187, 0.459)

5 Gaming: exclude 20% quitters Control £1,273 19.09Probability 34- 38 week quit: Incentives £1,320 19.12 £47 0.033 £1,443 0.74 Incentives 18%, Control 7% (-£47, £111) (-0.036, 0.121)

6 Use self reported quit rates Control £1,137 19.21 IncentivesProbability quit 34- 38 weeks: Incentives £1,121 19.21 - £16 0.003 Dominates 0.49 Incentives 39%, Control 21% (-£153, £86) (-0.14, 0.196)