public investment in bariatric surgery - queensland health · public investment in bariatric...

CentreforAppliedHealthEconomics

Public Investment in Bariatric Surgery

Economics and Evidence

Prof Paul Scuffham FAAHMS

Queensland Clinical Senate23-24th March 2017


Outline

• Cost-effectiveness• BudgetimpactinQueensland• Publicviews- whomtotreat

• Citizenjuries• Preferencesofthegeneralpublic


Cost-effectiveness analysis:

AIMS:

• Estimatemostefficientsurgicalapproachforbariatricsurgeryforsevere(BMI>35)andverysevere(BMI>40)obesecomparedtousualcare(UC)

• EstimateimpactonbudgetfromprovidingbariatricsurgeryinQueenslandpublichospitals

3


Model structure

4

5BMIweightclasses(healthstates):• normalweight(NW)• overweight(OW)• obese1(OB1)• obese2(OB2)• obese3(OB3)


Economic evaluation: parametersPerspective PublichealthcaresystemComparator Usualcare(UC)(conventionalpharmacotherapy,diet,exercise)Econeval type Cost-utilityanalysisSourcesofevidence Publishedclinicaltrials,systematic reviewsandmeta-analyses

Cohort 30year oldAustralianfemalewithmoderate(48%)tosevereobesity(52%)

Timehorizon Lifetime(50year duration)Outcomes CostsandQALYs

CostingsourcesQueenslandHealth.Samplecostdata:activitycosting(personalcommunication);AR-DRGsK10A,10B,11A,11B,12Z);MBSandPBSdataforcostsofUC,pre/postsurgery

Utilities•Australianpopulationnorms(SF-6D;Norman2013)•UtilityweightsperBMI classandco-morbidities(Kortt &Clarke2005)

Discountrate 5%forbothcostsandbenefits

5


Assumptions

• RepeatsurgeryforAGBandRYGB:• Basecasemodel:occurredwithinfirst2years• Scenarioanalysis:usedreoperationratesfromlongterm(>10years)studies.

• Note:nolong-termevidenceforreoperationratesforSG

• Regainofweight:• Basecasemodel:completeweightregainwithAGBbandremoval

• Scenarioanalysis:completeweightregainatdifferenttimeperiods

6


Results: Base case ICER (50 years / rest of life)

Basecase UC AGB RYGB SG

TotalCosts $118,965 $131,192 $135,043 $140,158

TotalQALYs 11.89 12.39 12.60 12.65

IncrementalCosts - $12,227 $16,078 $21,193

IncrementalQALYs - 0.50 0.71 0.77ICER(inc. cost/QALYgained) - $24,454 $22,645 $27,523

7

0

0

BenefitBenefitCostCostICER

i

i

--

=• QALY = quality-adjusted life year is a

generic measure including both quality and quantity of life lived.

• 1 QALY = one year in perfect health


Sensitivity analysis - ICERsAGB RYGB SG

ICER:basecase $24,454 $22,645 $27,523SensitivityanalysisAllmalepatients $24,623 $22,638 $27,615TreatOB3only $30,883 $40,067 $31,068TreatOB2only $17,652 $9,437 $24,041Fullweightregainat5years $378,180 $298,628 $487,691Fullweightregainat10years $130,253 $122,077 $158,256Fullweightregainat20years $54,399 $53,492 $65,18910%regainweightfor allbariatricsurgeries

$42,368 $39,571 $47,873

HigherratesforAGBandRYGBreoperations

$30,139 $36,096 $27,624

40yearsold $26,482 $26,355 $31,74150yearsold $30,472 $33,154 $39,42360yearsold $40,374 $48,065 $56,559

8

OB2 = better value for money

Longer weight kept off = better

SG best if repeat surgery for AGB or RYGB > ~20%

Younger = better value for money


Incremental costs & QALYs for T2 diabetic sub-group

Diabetic cohort

varied by age

AGB vs UC RYGB vs UC SG vs UC

Inc costInc

QALYInc cost Inc QALY Inc cost Inc QALY

Base Case: 30

years-$85,774 0.85 -$105,671 1.22 -$97,930 1.18

40 years -$115,297 0.85 -$134,885 1.18 -$126,925 1.15

50 years -$143,926 0.82 -$159,318 1.09 -$151,041 1.06

60 years -$156,403 0.70 -$164,476 0.90 -$155,748 0.87

9


Sensitivity analysis (T2 diabetics): Undiscounted

Diabetic cohort

varied by age

AGB vs UC RYGB vs UC SG vs UC

Inc costInc

QALYInc cost

Inc

QALYInc cost Inc QALY

Base Case: 30

years-$351,734 2.47 -$489,110 3.56 -$485,432 3.47

40 years -$344,731 2.11 -$442,526 2.91 -$437,397 2.84

50 years -$320,285 1.68 -$380,561 2.21 -$374,032 2.16

60 years -$267,409 1.16 -$294,094 1.47 -$286,235 1.44

10


Conclusions - cost-effectiveness

Bariatric surgery is:• cost-effective option for the management of severe

obesity, relative to usual care• cost saving for diabetic patients with severe obesity

(≥ BMI 35)• Substantial costs for surgery which take years to recoup• RYGB was more cost-effective than AGB and SG, but

results were sensitive to rates of reoperations• Follow-up care is crucial to prevent patients from regaining

their surgical weight loss

11


Financialestimates


Financial impact estimation:

Prevalence of obesity in QLD• Used epidemiological approach • Used incremental costs from base case ICER • Queensland 2014: 420,500 adults classified with severe obesity

(OB2/OB3)

Incidence of obesity in Qld• 21% increase over 2007/8 to 2014/15 (3% yearly)

• Used to estimate incidence rate of moderate-to-severe obesity (OB2/3)

• We assumed all patients were eligible for surgery (100% uptake rate over 5 years)

• Financial impact likely overestimated due to prevalence of comorbidities (surgery contraindications)

13


OB 3 = 33.7%; diabetes = 11.6%

Patient population (OB2/3+)

Year 1 Year 2 Year 3 Year 4 Year 5

Prevalent 426,892

Prevalent treated* 85,378 85,378 85,378 85,378 85,378 Incident (treated annually) 3,232 3,257 3,281 3,306 3,331

Total potential pool for treatment 88,610 88,635 88,659 88,684 88,709

14


BMI and T2 diabetes subgroups

15

259,876

34,101

132,000

17,321

OB 2 without diabetes OB 2 with diabetes OB 3 without diabetes OB 3 with diabetes


Cost in year 1 – treat incident population only:

16

Numbers treated Costs ($m)

OB 3+ without diabetes 962 $48.1OB 3+ with diabetes 126 $6.3OB 2 without diabetes 1,895 $94.7OB 2 with diabetes 249 $12.4Total 3,232 $161.6

If treat OB3+ only – minimum cost is $54m

Assumptions:• $50,000 per surgery


Cost in year 1:Incident population plus 20% of prevalent population

17

Numbers treated Costs ($m)OB 3 without diabetes 26,385 $1,319

OB 3 with diabetes 3,462 $173OB 2 without diabetes 51,946 $2,597OB 2 with diabetes 6,816 $341Total 88,610 $4,430

If treat OB3+ only – minimum cost is $1.5bn (incl 20% prevalent pop)

Assumptions:• $50,000 per surgery


Long-run financial impact of bariatric surgeries (annual)

18

For diabetic subgroups, RYGB has highest annual cost savings, for OB2 and OB3

For w/o diabetes subgroups, AGB is cheapest, for OB2 and OB3

The proportions in each subgroup will drive the total cost……..


Implications from treating T2 diabetes patients:

19

• For every 100 T2DM patients treated, can treat some non-diabetic patients and remain cost-neutral:

• AGB: 702• RYGB: 658• SG: 462

• However, cost-neutrality obtained over rest of life


Financial impact conclusions

20

• Substantial costs initially

• To keep pace with increasing obesity, need to treat at least 3500 patients annually = min of $161 million

• Treat prevalent population?• 45% funded through ABF, remainder has to be found

through State funding• Reduce other services to fund Bariatric surg?• Theatre capacity?


Views of the public:

1. Citizen Juries


Citizens’ Juries

• Increasingly used in health policy guidance in the UK (and globally) to seek informed public views (aka “citizen councils”)

• Democratic, deliberative process• Jurors engage with evidence presented by

experts and develop a community-centred focus

• Independent facilitator used


Citizens’ JuriesAIMS:• Develop criteria for patients to receive bariatric

surgery from a small random sample of the general (tax paying) population

• Make recommendations to Qld Health

---• Naïve sample but presented with evidence for

deliberation• At the end of the process = highly informed sample


The Process: Recruitment & Methods

Brisbane

• Sampling: Random + purposive

• 17 jurors*

• 3 day jury process

• 2 facilitators

• 6 witness sessions

• 445 mins total deliberation time

Adelaide

• Sampling: Convenience + purposive

• 12 jurors

• 1 day jury process

• (same) 2 facilitators

• 6 (shorter) witness sessions

• 195 mins total deliberation time

*18Brisbanejurors,however1jurorbecameillandcouldnotcompletethejuryprocess


The Process: Sessions and Expert Witnesses

Brisbane

1. Overview of Overweight and Obesity• Epidemiologist

2. Allied Health Professionals Panel• Exercise physiotherapist• Psychologist• Dietician

3. Surgery: Indications and Outcomes• Bariatric surgeon

4. Consumer Representatives Panel• Consumer who lost weight without surgery• Consumer who recently had surgery• Consumer who had surgery a number of

years ago

5. Bariatric Surgery: Should we do it?• Endocrinologist

Adelaide

1. Overview of Overweight and Obesity• Physician (kidney specialist, diabetes

researcher)

2. Allied Health Professionals Panel• Exercise physiologist• Psychologist• Dietician

3. Surgery Panel: Waitlists, Indications, Prioritisation and Outcomes

• Bariatric Surgery Coordinator• Bariatric Surgeon

4. Consumer Representatives Panel• Consumer on surgery waitlist since 2009• Consumer who recently had surgery• Consumer who had successful surgery


Outcomes: Criteria for determining access to public funding

Suggested Criteria

Brisbane verdict(All Brisbane criteria subject to a 5 year

review)

Adelaide verdict

Age 30 – 50 years No age restriction (Under 18 years considered in extreme cases)

Body Mass Index (BMI)

BMI ≥35 (Lower for certain (at risk) ethno cultural groups)

BMI ≥35

Comorbidity -Type II diabetes diagnosis-Other comorbidities considered

-Type II diabetes diagnosis in last 5yrs-If BMI ≥50, Comorbidity not required

Behavioural change

-Commitment shown through lifestyle changes over 6 months

-Commitment shown through changing diet and exercise-Opportunity to adopt a healthier lifestyle and demonstrate commitment


CJ Outcomes: Prioritisation of bariatric surgery in the public health system• Higher BMI• Comorbidities - develop methods to assess seriousness/ level

of risk• Demonstrated commitment to behavioural change • Age and means testing were considered of less importance

• Support programs to assist patients not eligible for public funding

• Brisbane: individually focussed support (from professional staff)

• Adelaide: public health approach


Views of the public:

2. Discrete Choice Experiments –general public


Discrete Choice Experiment (DCE)

Aims:• To measure the strength of preferences and

trade-offs for potential prioritisation criteria in a large sample of the general (tax-paying) public

• Derive importance weights for criteria that might be used to prioritise bariatric surgery for adults


DCE - design and administration• Rigorous scientific approach to elicit preferences

• Designed to identify trade-offs and strength of preferences• NOT an opinion survey

• Attributes and levels – criteria identified from expert focus group and literature

• e.g. Whitty et al., The Patient 2014• Design

• D-efficient design (9 blocks of 18) main + selected 2-way interaction effects, plus a consistency check Q

• Online survey Nov – Dec 2013• Sample – panel (target 2,000)

• quota by state (Qld, SA), age and gender


DCE– prioritycriteria forsurgeryScenarioThe following two people both need surgical management for their obesity. Surgery is likely to be the only way to reduce their body weight and their health risks. Both people meet the hospital’s clinical criteria for surgery, and the surgery has been recommended by their doctors.However, demand for the surgery is very high, and only one person can have their surgery now. The other person will have to wait at least another 12 months for surgery.

Each person answered 18 choices like this one


DC

E At

tribu

tes

and

Leve

lsATTRIBUTE LEVELSCurrent level of obesity • Obesity (BMI 30 to less than 40 kg/m2)

• Severe Obesity (BMI 40 to less than 50 kg/m2)• Very Severe Obesity (BMI greater than 50 kg/m2)

Obesity-related conditions • Already has obesity-related conditions• Is at risk of developing obesity-related conditions

Age of person needing surgery

• 20 years• 35 years• 50 years

Family history • At least one parent or sibling is obese, has had weight issues since childhood

• No family history of obesityChance of maintaining a substantial (at least half) reduction in excess weight

• 30%• 50%• 70%

Has shown commitment by responding to prescribed lifestyle intervention (i.e. physical activity and diet)

• Has maintained a healthy lifestyle plan for several months, resulting in some weight loss, however is still in need of surgery

• Has not maintained a healthy lifestyle plan and has had no weight loss

Time already spent on surgery waiting list

• 6 months• 1 year• 2 years


DCE Participants – Public (n=1,994)CHARACTERISTIC N % AustraliaFemale Female 1038 52.1% 50.2%Age Mean (SD) 46.6 (16.5)

≥50 years 849 42.6% 41.5%State Qld 1484 74.4%ATSI Yes 50 2.5% 2.5%Education (highest) Cert, Dip, Degree 892 44.7% 59% (25-64 yrs)Employment Part/full time 1075 53.9% 60.5% (15yrs+) Income (annual household) >AU$100k 374 21.8% 35.1% (>$104k pa)Private health insurance Hospital cover 945 47.4% 47% (NHS 2004-5)HEALTH N % AustraliaAQoL-8D (utility) Mean (SD) 0.69 (0.21) Mean 0.86BMI ≥25 1171 60.1% 61.4%Perceived weight Overwt/Obese 1052 53.5%HEALTH SERVICE USE N %≥1 hospital admission in last 12 mths 399 20.0%≥4 GP visits last 12 mths 679 34.1%Previous bariatric surgery (self or family) 141 7.1%


Priority points (Marginal rate of substitution)

79.81

38.81

26.80

10.66

2.03 1.000

20

40

60

80

100

Shown lifestyle

commitment

Very severe obesity

Already has comorbidities

Family history

Wait list per mth

Chance per %

Severe Obesity

Age of person 50yrs

Wei

ght


Conclusions from Public DCEImportant factors:• Lifestyle commitment very important • Very severe obesity (BMI >50)• Existing comorbidities

Relatively non-important as priority criteria• Age • BMI<50• Time on wait list• Chance of maintaining weight loss


Keypoints• Surgery is more cost-effective in higher BMI and those

with diabetes • Substantial costs for surgery

• If treat OB3+ and 20% prevalent pop = $1.5bn (annual)• If treat OB3+ incident pop = $54m (annual)

• Benefits accrued over rest of life• Large prevalent population• Public acceptability:

• Must show evidence of lifestyle/behaviour change• Higher BMI takes priority• Greater priority for those with comorbidities


Acknowledgements

• Contributors:• MrRobbieJames(CAHE)• MsCassandraRanatunga (CAHE)• MrRyanSalton(UK)• DrJoshuaByrnes(CAHE)• ProfJennyWhitty(CAHE/UEA)

• Manyothersinvolvedincitizenjuries,focusgroups,provisionofdataetc

37


Questions?

Thank you

public investment in bariatric surgery - queensland health · public investment in bariatric...

Documents