EVIDENCE-B

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HEALTH

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Fellow 52 (EBM course): 26 Oct 10

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OUTLINE

Why focus on decision making ?

How the decision is made ?

Analytic tools and approaches to enhance the uptake of EBPH

Examples and shared experience

Assignment

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WHY FOCUS ON DECISION MAKING ?

1. An enormous number of decisions is made

2. Under limited of health care resources

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HOW THE DECISION IS MADE ?

evidenceValuesneeds

resources

OBDM –opinion-based decision making

EBDM –opinion-based decision making

Increasing pressure

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EVIDENCE- BASED PUBLIC HEALTH INTERVENTIONAny intervention to improve the public health must act on at

least one of the health determinants of health

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genetic Health status

Physical env Social env

Biological env Health services

FOUR TYPES OF INTERVENTION

Health care

Educational

Social and community action

legislative

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HEALTH CARE

Effect population health > individual

Evidence of effectiveness of these intervention should meet the same requirement

Systematic review and RCT: gold standard

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EDUCATIONAL

Currently subject to less rigorous scrutiny then health care intervention

The Campbell Collaboration

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SOCIAL AND COMMUNITY ACTION

Difficult to evaluate in RCT

Unit of intervention = community

Cautious to interpreting the results

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THE USE OF LEGISLATIVE POWER TO IMPROVE THE PUBLIC HEALTH

Pragmatic about the influence of evidence during the decision making process

Public health profession VS politician

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ANALYTIC TOOLS AND APPROACHES TO ENHANCE THE UPTAKE OF EBPHWhat is the size of the public health problem?

Are there effective interventions for addressing problem?

What information about the local context and this particular intervention is helpful in deciding its potential use in the situation at hand?

Is a particular program or policy worth doing and will it provide a satisfactory return on investment, measured in monetary terms or in health impacts?

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PUBLIC HEALTH SURVEILLANCE

On going systematic collection, analysis and interpretation of specific health data

Integrated with the timely dissemination of these data to responsible person

Regularly evaluate the effectiveness of the use of the disseminated data

Exp: lead level in blood in the US population

used as the justification for eliminating lead painting and gasoline

Exercise: Identify the public health surveillance systems in your workplace and discussion about the systems, strength, weakness and possibility to improve

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SYSTEMATIC REVIEWS AND EVIDENCED-BASED GUIDELINES

One of the most useful sets of review for public health intervention:

the guide to community preventive services (http://www.thecommunityguide.org)

The quality of systematic review articles: see checklists

the local context condition

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Cost-effectiveness analysis (CEA)

Cost-utility analysis (CUA)

Cost-benefit analysis (CBA)

Economic evaluation

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MAJOR DIFFERENCE OF THESE ANALYSIS

Method Outcome Example Application

CEA Natural unit Life year saveFunctional status

Compare between programme measured in same unit

CBA Monetary term $, Baht Compared between programme producing different type of health outcomes

CUA Both qualitative and quantitaive aspects of health outcome

Quality-adjusted life years (QALYs)

Compared between programme producing different type of health outcomes

ECONOMIC EVALUATION: OTHERS

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Sensitivity analysisOptimization of resource allocation

PARTICIPATORY APPROACH

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Promise communities in EBPHStakeholdersThree groups: program operations

: those affected by the program : primary users of the evaluation

CASE STUDY 1: กองทุ�นทุ�นตกรรม

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evidenceValuesneeds

resources

Evidence: unit cost for specific servicePapers: Thai and other countriesAppraisal: methods and context : main papersAnalytic tool: Sensitivity analysis Present monetary valueApplication: based on these information

  paper 1     paper2  

Service UC-original Min%indirect Max%indirect Mean%indirect Min%LC Max%LC Mean%LC

Hexam 109 101 128 112 103 106 104OHImobile 41 37 49 42 38 40 39Hsealant 134 126 153 137 128 131 129Msealant 93 90 101 94 90 92 91HextractAdult 140 132 159 143 134 137 135HextractChild 125 117 144 128 119 122 120Mextract 84 81 92 85 81 83 82HfillAmgAdult 191 183 210 194 185 188 186HfillAmgChild 154 146 173 157 148 151 149MfillAmg 144 141 152 145 142 143 142HfillLC 318 310 337 320 311 315 313RCT 400 392 419 403 394 397 395Fixed 1758 1751 1778 1761 1752 1755 1754CD/SD 2693 2685 2712 2696 2687 2690 2688RPD 2265 2258 2285 2268 2259 2262 2261TP 603 595 622 606 597 600 598HScalingAdult 212 205 232 215 206 209 208HScalingChild 154 146 173 156 147 151 149MScaling 162 159 170 163 159 161 160

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CASE STUDY 2: RESOURCE ALLOCATION

Resource allocation for caries control program

in school dental health services

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nalysis of resource allocation in health care

The distribution of factors of production such as money, plant and equipment, and skilled labor among alternative uses

( Shim JK, Siegel JG, Dictionary of Economics, 1995 )

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Resource allocation

General objective

To identify optimal level and mix of three basic dental services (sealant and filling for permanent teeth and extraction of primary teeth) provided to primary school children under two different dental settings; hospital-based and mobile dental clinics under specified resources, service need and setting preference constraints

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Examples of developing modelExamples of developing model

A company produces 2 products: A and B

Resource requirements

are summarized in table

Resources available

Space 1,500 m2

Material 1,575 kg

Total hour 420 minutes

product

A B

Resource

Storage space (m2) 4 5

Material (kg) 5 3

Production time (mins) 60 30

Outcome

Selling price ($) 13 11

Developing LP model

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Resource dataResource data

Because of rigidities in hospital budget allocations, separate resource constraints were identified.

Provider time Assistant time Material cost Capital depreciated cost Supportive cost The mobile clinic included 2 dental nurses, 1 dental

assistant and 1 driver The average levels of service provision per school visit 30 sealants, 20 fillings or 50 extractions

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Need data Need data

Minimum cases of service need: hospital policies Sealant : all caries free first permanent molars of grade 1

children Filling and extraction : urgent cases Urgent fillings defined as caries in permanent teeth without history of continuous pain or abscess could be restored by amalgam filling. Urgent extractions defined as severe caries in primary

teeth which caused difficulty in chewing and cleansing.

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Preference data Preference data

Setting preference: parent’s WTP WTP hospital service VS WTP mobile service Example: WTP SH = 200, WTP SM = 220 Setting preference for sealant mobile > sealant hospital Setting preference for sealant = mobile Benefit of the service = adjusted WTP of each service Adjusted for SES, perception of child oral health,

experience of three basic dental services, experience of hospital or mobile dental clinic

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Data analysis

Solver linear programming module in Microsoft excel The output of the analysis is the level of services to be

provided for each service setting

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ResultsResults

Model 1:included all constraint, Model 2: included resource, Model 3: included resource and need, Model 4: actual service

Optimization condition of service-mix and WTP produced by service from different model

Model Service-mixed produced by service (cases)WTP produced by service (baht)

Hospital sealant

Mobile Sealant

Hospital filling

Mobile filling

Hospitalextraction

Mobile extraction

1 27061,020

18030,420

552124,752

828178,848

22828,044

53262,776

2 978221,028

00

22450,624

1,164251,424

00

5590

3 668150,968

00

21849,268

1,037223,992

00

74487,792

4 4810,848

28147,489

19143,166

17036,720

47958,917

67779,886

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ExerciseSealant program

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Sealant program

What do you think aboutsealant situation inlocal context?

evidence values

resources

Rationale

First AuthorBaseline

Age, Tooth % Loss

Year

1 2 3 4 5 15

Forss,1994 5-14, All 4 82

Bravo,19966-8, M1,2 17 87 75 62

Messer,1997 6-12, All N.A. 67 56

Holst, 19986-10, M1,2 N.A. 91 85 81 76 69

Wendt, 2001 6-8, M1 38 65

Review of sealant retention in Western

Countries

Review of sealant retention in Western

Countries

M1 = First permanent molar M2 = second permanent molar All = All permanent teeth, premolar and molar

First AuthorBaseline

Age, Tooth % Loss

Year

1 2 3 4 5 6 15

Forss,1994 5-14, All 4 5

Holst, 19986-10, M1,2 N.A. 8

Wendt, 2001 6-8, M1 38 13

Review of caries on sealed surface in Western

Countries

Review of caries on sealed surface in Western

Countries

M1 = First permanent molar M2 = second permanent molar All = All permanent teeth, premolar and molar

Rationale

Rationale

First AuthorBaseline

Age, Tooth % Loss

Year

1 2 3 4 5

Bonyaves,1994 6-9, M1 N.A. 64 56 49

Prashaya,1993 6-8, M1 N.A. 35 28

Tianviwat,2001 6-8, M1 N.A. 19

Thipsoonthornchai, 2003 6-7, M1 16 20 9M1 = First permanent molar

Review of sealant retention in

Thailand

Review of sealant retention in

Thailand

First AuthorBaseline

Age, Tooth % Loss

Year

1 2 3

Prashaya,1993 6-8, M1 N.A. 30

Tianviwat,2001 6-8, M1 N.A. 22

Thipsoonthornchai, 2003 6-7, M1 16 24 25

Review of caries on sealed surface in Thailand

Review of caries on sealed surface in Thailand

M1 = First permanent molar

Rationale

Transition analysis of Retention and Caries

Transition analysis of Retention and Caries

Sealant in Mobile Dental ClinicSealant in Mobile Dental Clinic

Discussion

Discussion

1. This study has lower retention rate of sealant and higher caries rate on sealed surface compared to western countries, although slightly better result than other Thai studies

2. Probability of losing of full retention was high in the first 6 months, approximately 1/3

The rate of this loss become less at around 12-25% in subsequence cycle

However, the transition probability toward caries is small (2-4%)

3. After partial loss, the probability of getting caries remarkably increased to 11-20%, whereas, the probability of total loss turning to caries is around 2-5%

Summary of findings

FromMarkov process

FromDescriptive analysis

Discussion

4. Determinants of sealant retention includes moisture control, assistant and cooperation of children

5. Partial loss lead to caries within 6 months with a rate 2.8 times higher than total sealant loss and 6.5 times that of among full retention group

Discussion

DiscussionSummary of findings (cont.)

From Transition OR

From Life table

SEALANT PROGRAM IN LOCAL CONTEXT

What do you think about sealant program situation in your area?

Is it effective?

Is it worth to do? Good VS Harm

Any data or information do you need to answer this problem?

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