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ABC Project Update WP2: Discrete choice experiment design Dyfrig Hughes, Emily Fargher, Val Morrison ABC Project Workin - PowerPoint PPT Presentation

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ABC Project Update WP2: Discrete choice experiment design Dyfrig Hughes, Emily Fargher, Val Morrison ABC Project Working Meeting September 2009. MARS (Adherence measure). LOT (Optimism). Prospect theory. Outcome expectancies X outcome value. B E H A V I O U R. Demographics

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ABC Project UpdateWP2: Discrete choice experiment designDyfrig Hughes, Emily Fargher, Val MorrisonABC Project Working MeetingSeptember 2009

Tpb abc questionnaire map l.jpg


(Adherence measure)



Prospect theory


expectancies X

outcome value











e.g. age, gender


Past experience




MDQ Add On

(Behaviour intention)


(Adherence measure)

Time Pref. Questions

(Economic theory)

Bilateral Bargaining

(Economic theory)

TPB Questionnaire

Adapted MDQ

(Theory of planned behaviour)

Time preference



Normative beliefs

X motivation to comply

Subjective norm



Perceived internal

and external

control factors




TPB: ABC Questionnaire Map


(Self-regulation theory)

Health Beliefs Model


(Self-regulation theory)


(Stated preference)

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Discrete choice experiments

  • Developed in the 1990s to elicit views on health care

  • Based on the idea that goods and services are described by characteristics (attributes)

  • The levels of these characteristics determines the extent to which the individual values these goods and service

  • DCE is used to

    • Show how people are willing to trade between characteristics

    • Produce overall benefit scores for alternative ways of providing health care

    • Estimate the relative importance of different characteristics of a service

    • Estimate whether an attribute is important

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Example choice question

Hypothetical scenario


Varying levels

Binary choice


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DCE methodology

  • Identification of attributes

    • Policy, RCTs, literature

    • Source: policy, RCTs, literature

  • Identification of associated levels

    • ACTIONABLE, PLAUSIBLE and capable of being TRADED OFF

      • Cardinal (dose frequency OD, BD)

      • Ordinal (severe vs. moderate ADR)

      • Categorical (GP versus pharmacist)

  • Design choice scenarios

  • Questionnaire

  • Input, analysis and interpretation

    • U = β1Sym + β2Freq + β3S_ADR + β4M_ADR ... + e

  • Checklist!

    Lancsar E. & Louviere J. (2008) Conducting discrete choice experiments to inform healthcare decision making. Pharmacoeconomics 26(8): 661-677.

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Stage 3: Choice scenarios

  • Greater the number of attributes and levels, the greater the number of possible profiles

    • Possible profiles = LevelsAttributes

    • 2 attributes at 2 levels = 22 = 4

    • 4 attributes at 4 levels = 44 = 256

    • 3 attributes at 3 levels and 1 attributes at 2 levels

      • = 33 x 21 = 54

      • Design catalogue e.g.

      • 24 runs

  • Substantial questionnaire of Multiple pages

    • Coast J., Flynn T.N., Sailsbury C., Louviere J., & Peters T.J. (2006) Maximising responses to discrete choice experiments - a randomised trial. Appl Health Econ Health Policy 5(4): 249-260.

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What next?

  • Confirm survey content

    • Confirmation of questionnaires to be inc. in survey

    • Confirmation of DCE design (length)

  • Translation

  • Validation of instruments

  • Co-ordination of ethics

  • Pilot – all countries?

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ABC Project UpdateWP3: Econ & psychological determinants reviewDyfrig Hughes, Emily Fargher, Val MorrisonABC Project Working MeetingSeptember 2009

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Systematic Review of behavioural models of adherence to medicines: Economic & psychological perspectives

T3.1 “Systematic review of the literature: Studies that have assessed the psychological and economic basis for non-compliance, together with structured models of compliance behaviour will be identified using computerised search in relevant databases, retrieved and analysed.”

Review Question: Which models in the economics and psychology literature may explain adherence to medicine?

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Search strategy

A series of independent search strategies, across databases, will be used to identify papers in the economics and psychology literature.

For consistency the search strategy used to identify adherence papers in WP1 will be used throughout this work package.

Databases to be searched: MEDLINE, EMBASE, The Cochrane Library, CINAHL, PsycINFO, PsycLit, EconLit

Inclusion Criteria: Papers containing EMPRICIAL data reporting adherence OR reporting a behavioural model or theory or adherence

Exclusion Criteria: Non-pharmaceutical studies

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Search strategy stages

Search One

Economic models based on cost

1. Adherence terms

2. Cost terms

3. 1 AND 2

4. Limit 3 to review

Search Two

Economic models exc. cost

1. Adherence terms

2. Econ theory terms

3. 1 AND 2

Search Three

All other

economic models

1. Adherence terms

2. Generic catch all

3. Econ Eval. terms

4 2 NOT 3

5. 1 AND 4

Search Five

All other psychological models

1. Adherence terms

2. Generic catch all

3. 1 AND 2

Search Four

Psychological models

1. Adherence terms

2. Psychological theory terms

3. 1 AND 2

Economic models

Psychological models

screen all papers using the same criteria

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What next?

  • Held teleconference and decided …

  • Run searches & re-convene in October to agree next stage:

  • Independent screen of titles and abstracts by 2 reviewers

  • Data Extraction:

    • Study characteristics

    • Measure of adherence (+ critique of measure of adherence)

    • Key Findings

    • Behavioural model e.g. Consumer choice theory, Theory of planned behaviour etc. (+ Critique of experiment used to test model)

  • Final stage: using results of review & expertise within the group develop the model.

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Thank youDyfrig Hughes, Emily Fargher, Val MorrisonABC Project Working MeetingSeptember 2009