Duc Anh Ha MD., MS. DrPH Candidate Boston University School of Public Health

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Application of WHO-CHOICE for Cost Effectiveness Analysis of Interventions

to prevent Cardiovascular disease in Vietnam

Duc Anh Ha MD., MS. DrPH Candidate

Boston University School of Public HealthBoston, February 3, 2010

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Outline

• Introduction• Epidemiology and intervention• Methods and data• Results• Discussion and policy Implications• Question and answer

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Introduction

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Scarcity in healthcare

• Resources for healthcare are limited, especially in LMICs

• G8 spent 10% GDP on healthcare in 2007

• All LMICs spent half of G8’s spending

• Health spending in the poorest countries ($20-50 per capita) is 1/30 the level of that in developed countries

• Burden of financing is becoming heavier

• Rationale choices must be made to meet the health care needs and to deal with scarcity

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Economic evaluation in healthcare

• Definition: “The comparative analysis of alternative courses of action in terms of both their costs and consequences” (Drummond 2005).

• Involves: identifying, measuring, valuing, and comparing costs and consequences

• Deals with both scarcity and choices

• An established tool to aid health policy makers

• Be applied in a variety of healthcare areas in many developed countries, but in only few LMICs

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Economic evaluation and efficiency

Heath financing functions Intermediate outcomes Health system goals

Source: Adapted from Roberts at al, and WHO’s report 2000

Equity

Access

Quality

Efficiency Responsiveness

Equity in health

Financial risk protection

Health gainResources mobilization

Pooling

Purchasing/ provision

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CHOosing Interventions that are Cost Effective (WHO-CHOICE)

• Central notion– Allocate resources across interventions and population

groups to attain the highest possible level of health

• Key features– Permits analysts to evaluate the costs and health benefits of

a set of related interventions singly or in combination – Presents the results of CEA in a single table, in which

interventions form an “expansion path” – Overcomes time, technical, data, budget constraints facing

developing countries

• Application of WHO-CHOICE in Vietnam– Adaptation of regional information down to the national level– Availability of national data on demographic and

epidemiological parameters

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The context of Vietnam

• Recent socio-economic development– Population: 85 million, 30% of whom live in urban areas– Innovation process (Doi moi) was launched in 1986– Economic growth: 7-8% over the last decade– Poverty rate: 18% (2007) compared to 75% in the mid 80s

• Health reforms– Liberalization of the health care and pharmaceutical markets– Introduction of official user fees and health insurance

• Health care financing – State budget for health care: 5% of GDP ($18 per capita) in

2006– Out-of-pocket payment: 70% of total health expenditures– Resources are allocated on the basis of past expenditure and

unscientific norms, and request-give mechanisms

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• CVD in Vietnam– Leading cause of death (one third of total deaths)– Account for 20% of total burden of DALYs– Risk factors of CVD (hypertension, smoking, obesity) are either on

the rise or already at alarming levels– Among 23 countries accounting for 80% of global chronic disease

deaths

• Milestones of the prevention and control of CVD in Vietnam:

– 2000: issue of National Tobacco Control policy– 2001: ratification of the National Strategy for People’s Health Care

for the period 2001-2010– 2002: ratification of Prevention and Control Program for certain

NDCs – 2007: establishment of the NCDs program attached to the MOH

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Objectives

• Overall objective:– To inform policy makers about the costs, effects, and cost-

effectiveness of prevention interventions, and how they can be combined to efficiently prevent and reduce CVD risk factors in Vietnam.

• Specific objectives– To describe the burden of cardiovascular disease and its

risk factors;– To estimate the costs, health effects, and cost-effectiveness

of interventions to prevent cardiovascular disease in Vietnam;

– To propose interventions to efficiently prevent and reduce the risk factors of CVD in Vietnam;

– To share lessons learned from the contextualization of WHO-CHOICE into Vietnam’s setting.

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Epidemiology and prevention

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Definitions

• Cardiovascular disease:– A term referring to a class of diseases involving not only

conditions of the heart such as coronary artery, valvular, muscular, and congenital disease, but also hypertension and conditions of the cerebral, carotid, and peripheral circulation (Howson 1998).

• Ischemic heart disease:– includes acute-myocardial infarction (AMI), angina, and

congestive heart disease following AMI.

• Stroke:– rapidly developing clinical signs of focal (or global)

disturbance of cerebral function, with symptoms lasting 24 hours or longer or leading to death, with no apparent cause other than of vascular origin (Hatano 1976).

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Trends in morbidity in Vietnam

0

10

20

30

40

50

60

70

1976 1986 1996 2006

Year

Perc

ent

Communicabledisease

Non-communicabledisease

Injuries,poisoning

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Burden of mortality in Vietnam

GBD cause Estimated total deaths per 1,000

Cardiovascular diseases 168.8

Infectious and parasitic diseases 67.6 Malignant neoplasms 64.1

Respiratory diseases 51.2

Unintentional injuries 33.5

Source: WHO, Disease and injury country estimates

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Burden of DALYs in Vietnam

0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20%

Cardiovascular diseases

Unintentional injuries

Neuropsychiatric conditions

Malignant neoplasms

Respiratory diseases

Infectious and parasitic diseases

Digestive diseases

Sense organ diseases

Intentional injuries

Musculoskeletal diseases

Percentage of total DALYs

YLL

YLD

Source: Vos et al, unpublished report

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Risk factors and economic burden

• High blood pressure:– Prevalence: 16.9% among people aged 25-65 (a 51% increase

since 1992), and 50% among people aged over 65 in 2002• Obesity:

– increases 2.5 times over the 1992-2002 period• Smoking

– 56% males aged 16 and over smoke• Salt intake:

– Predominant use of salt to preserve meat and fish, and in seasoning and sauces

• Knowledge of CVD and its risk factors:– Poor perception on risk factors: correct perception 23%; wrong

perception: 37%• Economic burden:

– Direct costs for treatment and management – Indirect costs: lost of productivity, future earnings, and loss of care

givers

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Prevention intervention

• Population-wide interventions – The majority of cases of CVD occur among persons with

medium and low levels of risk– A small change in risk factors in the population at large may

bring greater benefits than a large change in only a small group of high risk people

– Lifestyle modification/environment changes

• Individual interventions– Identify high risk susceptible persons, and offer them some

protection– Based on elevated levels and absolute risks– Thrombosis prevention (aspirin), blood pressure lowering

(diuretics, beta-blockers, and Angiotensin-converting enzyme (ACE) inhibitors), and cholesterol lowering (statin)

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Methods and Data

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Methodological framework

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Selected interventions

A Population-wide interventions

P1 Health education program through the mass media to reduce salt intake

P2 Health education program through the mass media to reduce smoking

P3 Health education program through the mass media to reduce cholesterol concentration

P4 Combination of P1, P2 and P3

B Individual interventions

I1-2 Individual treatment of systolic blood pressure (SBP >140 and >160 mmHg)

I3-4 Individual cholesterol-lowering drug treatment (statins) (CHOL> 5.7 and >6.2 mmol/l)

I5 -8

Combination treatment with triple therapy of hypertension lowering drug for individuals with absolute risks of cardiovascular event in the next 10 years of 5%, 15%, 25%, and 35%

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Data collection of intervention effectiveness• Demographic data:

– United Nations Population’s Division Bureau (2007)• Current epidemiology of IHD and stroke:

– National Burden of Disease study• Prevalence information:

– Systolic blood pressure: Vietnam National Health survey;– Smoking: the 2001 and 2008 risk factor surveys;– Salt intake profile: Intersalt project

• Relative risk for IHD and stroke:– The Comparative risk assessment project (WHO)

• Health state valuation/disability weight: – National Burden of Disease study

• Preventive intervention effectiveness:– Systematic review, meta-analysis, and published articles

• Current coverage of intervention and compliance: – Experts’ opinions

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Summaries of effect sizes

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Intervention costs

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Data sources

• Data on physical inputs (ingredients) and quantities– WHO-CHOICE database

• Drug prices– International Drug Price Database (MSH 2007)

• Personnel costs– United Nations and European Union’s salary scale and Government

of Vietnam’s regulation

• Media operating and IEC materials– Vietnam Television – Voice of Vietnam– Local television and radio stations– Thanh Nien publishing

• Patient costs– Vietnamese costing study 2004

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Prices/Unit costs

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Prices/Unit costs

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Cost analysis

• CostIt (Costing Intervention Templates) was used to aggregate the cost components

• Perspective: societal perspective

• Choice of discount rate: 3%

• Capacity utilization assumption: 80%

• Program implementation horizon: 10 years

• Annualization: subjected costs will be annualized over the intervention implementation horizon

• Exchange rate: US$ 1= 16421 VND for the base year 2007

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Modeling the impacts on disease outcomes

• Stata modeling– Estimates population effects (expected rates of IHD and

stroke incidence) with or without the implementation of the prevention measures

– Undertaken by means of a simulation model based on APCSC that applies the aforementioned effect sizes to the observed risk factor profile of different age and sex groups in the Vietnamese population

• PopMod modeling– Estimates the lifetime health gains experienced by the

population as a result of the intervention-induced changes in disease incidence

– Both IHD and stroke were explicitly modeled first without any intervention and then with the various interventions in place for 10 years

– Tracks the effects over lifetime (100 years)– Quantifies population health effects to DALYs averted

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Calculating cost-effectiveness

• Both single or combined interventions were assessed

• Null scenario: none of the proposed interventions was implemented

• Classifications of average CER– Very cost-effective: averting each DALY at a cost less than

1 time GDP per capita; – Cost-effective: averting each DALY at a cost between one

and three times GDP per capita; and – Cost-ineffective: averting each DALY at a cost over three

times GDP per capita.

• GDP per capita: VND13,456,000 (US$ 820) in 2007

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Uncertainty analysis

• One-way sensitivity analysis– Lower and upper limits of intervention effects– Half and double the base estimates of drug prices– Age-weight and discounting of health

effectiveness

• Multi-way sensitivity analysis– Best-case and worst-case scenarios

• Probabilistic, multivariate sensitivity analysis– Monte Carlo League

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Results

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Costs

Intervention Total cost per year Total cost per capita per

VND billion US$ millionyear

VND US$

Media salt campaign 89 5.4 1,050 0.06

Media smoking campaign 89 5.4 1,050 0.06

Media cholesterol campaign 89 5.4 1,050 0.06

Mass media combination 167 10.2 1,960 0.12

Treatment of SBP>140mmHg 941 57.2 11,044 0.67

Treatment of SBP>160mmHg 264 16.0 3,094 0.19

Treatment of Chol >5.7mmol/l 2,460 149.8 28,934 1.76

Treatment of Chol >6.2mmol/l 1,174 71.5 13,805 0.84

Combination treatment (>5% risk) 4,121 250.3 48,345 2.94




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Typical percentage shares in program costs of population-wide interventions

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Typical percentage shares in total costs of individual interventions

0%

10%

20%

30%

40%

50%

60%

Treatment of SBP Treatment of Cholesterol Combination treatmentof absolute risk

Perc

ent

HospitalBed Days

Hospitalvisits

Healthcentre visits

Drugs

Lab tests

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Health effectiveness in DALYs averted

InterventionAge-weighted,

discountedDiscounted

only No age-weight,

undiscounted

Media salt campaign 459,392 656,679 1,138,693

Media smoking campaign 72,502 101,219 176,041

Media cholesterol campaign 369,822 463,835 837,193

Mass media combination 753,790 993,757 1,775,259

SBP>140mmHg 2,565,593 3,576,194 6,301,577

SBP>160mmHg 2,053,290 2,901,530 5,081,202

Chol >5.7mmol/l 781,795 966,973 1,740,646

Chol >6.2mmol/l 523,916 636,085 1,150,521

AR>5% 4,046,844 5,709,669 9,893,910

AR>15% 3,448,683 4,975,973 8,530,057

AR >25% 3,037,140 4,428,497 7,555,891

AR>35% 2,647,161 3,898,727 6,623,977

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Cost-effectiveness of interventions

Intervention

ACER per DALY saved

ICER per DALY saved

CMH category

VND US$

Media salt campaign 1,945,002 118 Dominated Very cost-effective

Media smoking campaign 12,324,059 751 Dominated Very cost-effective

Media cholesterol campaign 2,416,075 147 Dominated Very cost-effective

Mass media combination 2,211,140 135 Dominated Very cost-effective

SBP>140mmHg 3,660,315 223 13,194,115 Very cost-effective

SBP>160mmHg 1,281,596 78 1,281,596 Very cost-effective

Chol >5.7mmol/l 31,469,764 1,916 Dominated Cost-effective

Chol >6.2mmol/l 22,404,550 1,364 Dominated Cost-effective

AR>5% 10,157,911 619 30,240,689 Very cost-effective

AR>15% 6,674,633 406 17,547,288 Very cost-effective

AR >25% 5,201,348 317 13,585,810 Very cost-effective

AR>35% 4,251,785 259 Dominated Very cost-effective

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Point estimated expansion path

P1P2 P3P4

I 1

I 2

I 3

I 4

I 5

I 6

I 7I 8

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Tota

l cos

ts (V

ND

bill

ions

)

DALYs averted (millions)

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Incremental cost-effectiveness ratios

1.28

13.19 13.59

17.55

30.24

3.665.20

6.67

10.16

1.28

-

5

10

15

20

25

30

35

Individualtreatment

(SPB>160)

Individualtreatment

(SPB>140)

Combination drugtreatmen (>25%

absolute risk)

Combination drugtreatmen (>15%

absolute risk)

Combination drugtreatmen (>5%absolute risk)

CER

(VN

D m

illio

ns/D

ALY

ave

rted)

Intervention

ICERACER

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Results of sensitivity analysis

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Expansion path combination

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Uncertainty around ICERs

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

0 1 2 3 4 5 6 7

DALYs saved per year (millions)

Cos

t per

yea

r (VN

D b

illio

ns)

Salt campaign

Smoking campaign

Cholesterol campaign

Mass mediacombinationTreatment of SBP>140

Treatment of SBP>160

Treatment of Chol>5.7mmol/lTreatment of Chol>6.2mmol/lCombination treatment(>5% risk)Combination treatment(>15% risk)Combination treatment(>25% risk)Combination treatment(>35% risk)

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Stochastic budget expansion path

Media salt campaign

Media salt campaign

Media salt campaign

Media salt campaign

Media combination

Media combination

Media combinationMedia combination

Media combination



Treatment of SBP>160 Treatment

of SBP>160





20%

30%

40%

50%

60%

70%

80%

90%

100%

69 89 109 129 149 169 189 209 229 249 269 289 309 329 349 369 389 409 429 449 469 489

Budget per year (VND billions)

Prob

abili

ty o

f bei

ng c

ost-e

ffect

ive

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Discussion and policy implications

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Principal findings

• Vietnam is in the second stage of the epidemiologic transition

• CVD is the leading cause of death

• Risk factors of CVD are either on the rise or already at alarming levels

• Limited application and evidence of EE in Vietnam

• Majority of population-wide and individual interventions are cost-effective according to CMH

• Without budget constraint, treatment for SPB>160 and absolute risk approach should be implemented

• With highly restricted resources: Mass media to reduce salt intake and cholesterol are probable interventions

• Using local and context-specific information to apply WHO-CHOICE is a promising approach to improve evidence-based health policy making in developing countries

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Study limitations

• No local data on sodium consumption

• Effect sizes and equations were derived from developed countries

• Did not fully take into account other benefits or side effects into the models – Decrease of the risk of gastric cancer– Resistance caused by platelet-active drugs

• Care must taken when interpreting results of uncertainty analyses (stochastic league table)

• Not all parameters were assessed in sensitivity analyses– Hospital costs (double the base estimates) – Discount rate 10% or higher

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Comparison with other studies

• Many findings were consistent with those by Murray et al for the WPRB

• Average cost-effectiveness estimates are significantly higher than the regional estimates

• Different expansion path combination

• Pharmaceutical interventions had similar CE results as compared with other studies in developing countries

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Policy implications

• The proposed interventions are economically sustainable measures:– target well documented behaviors and risk factors;– could lead to favorable changes in behaviors or risk factors;– be very cost effective and financially feasible in the context of

Vietnam.

• Utilizing the results would lead to increased efficiency in resource allocation

• Contribute to reducing both economic and health burden of CVD

• Go in line with WHO’s recommendations and pro-poor viewpoint of Vietnamese government

• Improve health policy making based on evidence

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Specific recommendations

• Lifestyle modification education program via mass media– Affordable intervention at the current budget of VND

80billion per year– Pilot in some provinces before scaling up nationally– In the long run, should be a part of the national media

strategy

• Expanding individual treatment of systolic blood pressure – The budget is projected to increase– Combine follow up visit and health education– Attention should be paid to adherence to treatment

• Piloting treatment based on absolute risk – Use WHO guidelines for assessment and management – Training for health workers at the primary level

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Lessons learned

• Form a good panel of expert– Present multiple disciplines – Knowledgeable of local context and data sources

• Understand intervention pathways – Understand biological process of the disease and the

impact of the intervention

• Be focused on identifying and synthesizing evidence

– As a rule of thumb, the evidence should not be identified selectively, but derived from the best designed and least biased sources.

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Questions?

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Thank YOU!

Duc Anh Ha MD., MS. DrPH Candidate Boston University School of Public Health

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