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ABC Project Update WP2: Discrete choice experiment design Dyfrig Hughes, Emily Fargher, Val Morrison ABC Project Working Meeting September 2009
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Behaviour intention Demographics e.g. age, gender Personality Past experience Outcome expectancies X outcome value Normative beliefs X motivation to comply Perceived internal and external control factors Attitude towards behaviour Subjective norm Perceived behavioural control BEHAVIOURBEHAVIOUR Time Pref. Questions (Economic theory) LOT (Optimism) TPB Questionnaire Adapted MDQ (Theory of planned behaviour) MDQ Add On (Behaviour intention) Bilateral Bargaining (Economic theory) BMQ (Self-regulation theory) Brief-IPQ (Self-regulation theory) Health Beliefs Model DCE (Stated preference) MARS (Adherence measure) Morisky (Adherence measure) TPB: ABC Questionnaire Map Prospect theory Time preference Human capital
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Questionnaire suggestions QuestionnaireNo. items Measure / Theory MARS5Adherence Morisky8/4Adherence Breif_IPQ9Self-regulation theory BMQ11Self-regulation theory LOT_R10Optimism TPB (Adapt_MDQ) 15Theory of planned behaviour Time Preference4/2Time preference DCE16Stated 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 Rank Binary choice Varying levels Attributes Hypothetical scenario
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Recent example
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DCE methodology 1. Identification of attributes Policy, RCTs, literature Source: policy, RCTs, literature 2. 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) 3. Design choice scenarios 4. Questionnaire 5. Input, analysis and interpretation U = β 1 Sym + β 2 Freq + β 3 S_ADR + β 4 M_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 1&2
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Stage 3: Choice scenarios Greater the number of attributes and levels, the greater the number of possible profiles Possible profiles = Levels Attributes 2 attributes at 2 levels = 2 2 = 4 4 attributes at 4 levels = 4 4 = 256 3 attributes at 3 levels and 1 attributes at 2 levels = 3 3 x 2 1 = 54 Design catalogue e.g. http://www.research.att.com/~njas/oadir/http://www.research.att.com/~njas/oadir/ 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 Update WP3: Econ & psychological determinants review Dyfrig Hughes, Emily Fargher, Val Morrison ABC Project Working Meeting September 2009
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ABC WP3 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 Four Psychological models 1. Adherence terms 2. Psychological theory terms 3. 1 AND 2 Search Five All other psychological models 1. Adherence terms 2. Generic catch all 3. 1 AND 2 Economic modelsPsychological models screen all papers using the same criteria
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Strategy examples
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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 you Dyfrig Hughes, Emily Fargher, Val Morrison ABC Project Working Meeting September 2009
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